NIOS Lesson 30 - DRUGS AND MEDICINES

The association of mankind with pain and disease is probably as old as man himself.

Humans have always been looking for remedies to overcome their pain and suffering. The earliest attempts at this, involved use of various plants. The knowledge was based on experience and was handed on from generation to generation. It is being used even today.

In an attempt to conquer pain and disease, a large number of synthetic chemicals have been discovered. The chemicals used as medicines are known as pharmaceuticals. Today pharmaceutical industry has grown to be one of the biggest industries in the world.

In this lesson we will try to introduce you to the area of drugs and medicines. In the process we would attempt to differentiate between drugs and medicines (though commonly used interchangeably). You will also learn about classification of medicines and other important aspects of drugs and medicines.

OBJECTIVES

􀁺 define drugs and medicines;

􀁺 differentiate between drugs and medicines;

􀁺 classify medicines on the basis of their action (use);

􀁺 cite examples and effects of analgesics, antipyretic, antiseptics, disinfectants, antacids, antimalarials, anaesthetics, antimicrobials (sulpha drugs and antibiotics), anti-fertility drugs, etc.;

􀁺 differentiate between analgesics and antipyretics;

􀁺 differentiate between antiseptics and disinfectants;

􀁺 explain habit forming and non-habit forming drugs;

􀁺 differentiate between broad spectrum and narrow spectrum antibiotic;

􀁺 differentiate between local and general anaesthetics;

􀁺 describe self-medication and

􀁺 alternate systems of medicine.

30.1 WHAT ARE DRUGS AND MEDICINES?

When we fall ill we take some tablets, pills, injections or apply some ointments to get well. All these are collectively known as medicines. Some time we may use some parts of plants or some preparations made from herbs, minerals, animals, etc. All these substances used for the treatment or prevention of diseases, can also be called medicines. Medicines contain a single chemical or a number of chemicals in different amounts to have the desired effect.

The mode of action of the chemicals of a medicine is quite varied and complicated.

In many a cases mode of action may not be fully known to us, but we continue to use them as they are useful to us.

Early man used several plants or parts of plants to cure diseases, without knowing of the chemical components, responsible for it. For example bark of willow tree was used for relieving pain (as analgesic). Later, it was found that its bark contained 2-hydroxy benzoic acid, which is closely related to acetyl salicylic acid (also known as aspirin). Parts of a plant Rauwolfia serpentina (Hindi name, sarpagandha) have been used in Ayurvedic drugs for the treatment of hypertension (high blood pressure). Later on it was discovered that a compound called reserpine was responsible for reducing blood pressure. Thus reserpine became the firstmodern medicine to control blood pressure.

In most of the cases nature led to the discovery of modern medicine. Thousands of chemists all over the world are constantly searching for better, efficient, cheaper and safer medicines.

As mentioned earlier the term drugs and medicines are used interchangeably, but there is a difference between the two. Let us try to understand the difference between drugs and medicines.

The term drug is often used for preparations or formulation whose chemical components and their quantities are not known fully. These may be extracts of certain plants, herbs, animal parts or may be minerals.

The term medicine is used when the chemical composition and the quantities of various chemical components are known. Further, the effects of the chemical compounds present in a medicine and their side effects have been properly and extensively studied. The medicines are approved by the relevant governmental authorities like Drug Controller of India.

The term drug is also used for substances, which are habit forming and are often abused, for example, narcotics like cocaine, morphine, heroine, marijuana, etc.

As you read in newspapers terms like illegal drug trade, drug trafficking, drug mafia, drug peddler are used to refer to illegal dealing with habit forming substances, referred to as drugs.

However the difference between drug and medicine is far from clear.

INTEXT QUESTIONS 30.1

1. Write a definition of medicines.

Medicines are all those substances or formulations which are used for cure,

treatment, prevention of diseases or disorders and recovery of a patient.

2. Most of the chemicals used in medicines are poisonous. Is this statement true or false? T

3. What are pharmaceuticals?

Pharmaceuticals are the chemicals which are used as medicines.

4. Name the compound which is present in the plant sarpagandha and is responsible for reducing blood pressure.

Reserpine

30.2 CLASSIFICATION OF MEDICINES

You may be familiar with some of the common medicines used for relieving pain, reducing fever or for treating common cold, etc. The number of medicines is very large therefore medicines are classified according to their action or use. Table 30.1 provides a list of some important classes of medicines. The terms like analgesics, antibiotics, antiseptics, etc. are common household words. Let us try to understand the meaning of this classification in a little more detail.

Medicines are classified in multiple ways — by their therapeutic use (e.g., antibiotics, analgesics), chemical structure, mechanism of action, organ system affected, and legal/regulatory status. Globally, the WHO’s ATC system is the most widely used, while in India drugs are also grouped under schedules like H, H1, and X for regulation.

🔑 Major Systems of Medicine Classification

1. Therapeutic Use

Groups drugs by the disease or symptom treated.
Examples:
- Antibiotics → fight infections
- Analgesics → relieve pain
- Antihypertensives → lower blood pressure

2. Pharmacological/Mechanism-Based

Based on how the drug works at the molecular level.
Examples:
- Beta-blockers → block adrenergic receptors
- ACE inhibitors → inhibit angiotensin-converting enzyme
Provides insight into side effects and drug interactions.

3. Chemical Structure

Groups drugs by chemical nature.
Examples: alkaloids, steroids, glycosides.
Useful for research but less practical clinically.

4. Organ System-Based

Drugs classified by the body system they affect.
Examples:
- Cardiovascular drugs
- Respiratory drugs
- Nervous system drugs

5. Legal/Regulatory Classification

In India, drugs are grouped under Schedules H, H1, and X:
- Schedule H → prescription-only
- Schedule H1 → stricter control (e.g., certain antibiotics)
- Schedule X → narcotics/psychotropics, highly restricted
Controlled substances regulated under the NDPS Act, 1985.

6. WHO ATC System

International standard: Anatomical Therapeutic Chemical (ATC) classification.
Drugs divided into five levels:
- 1st → organ/system (e.g., cardiovascular)
- 2nd → therapeutic subgroup
- 3rd & 4th → pharmacological/chemical subgroup
- 5th → specific chemical substance
Example: Metformin → A10BA02 (antidiabetic drug). WHO

📊 Comparison Table

System	Basis	Examples	Usefulness
Therapeutic	Disease/symptom treated	Antibiotics, analgesics	Clinically practical
Pharmacological	Mechanism of action	Beta-blockers, ACE inhibitors	Explains drug effects
Chemical	Molecular structure	Steroids, alkaloids	Research-focused
Organ system	Site of action	Cardiovascular, respiratory	Educational
Legal/Regulatory	Law & safety	Schedule H, X	Controls misuse
WHO ATC	Global coding system	Metformin A10BA02	Standardized worldwide

⚠️ Key Considerations

Overlap exists: One drug may fit multiple categories.
India-specific rules: Regulatory schedules matter for availability.
Global standardization: ATC system ensures consistency in research and epidemiology.

Would you like me to dive deeper into therapeutic classes (like antibiotics, antivirals, analgesics) or into India’s regulatory schedules for a more region-specific view?

Medicines can be grouped into broad classes depending on their purpose, mechanism, or chemical nature. Here’s a clear breakdown:

🩺 Major Classes of Medicines

1. Analgesics

Relieve pain.
Examples: Paracetamol, Ibuprofen, Morphine.

2. Antibiotics

Kill or inhibit bacteria.
Examples: Penicillin, Amoxicillin, Ciprofloxacin.

3. Antivirals

Target viral infections.
Examples: Acyclovir (herpes), Oseltamivir (flu).

4. Antifungals

Treat fungal infections.
Examples: Fluconazole, Clotrimazole.

5. Antiparasitics

Act against parasites.
Examples: Albendazole (worms), Chloroquine (malaria).

6. Antihypertensives

Lower blood pressure.
Examples: Beta-blockers, ACE inhibitors, Calcium channel blockers.

7. Antidiabetics

Control blood sugar.
Examples: Insulin, Metformin, Sulfonylureas.

8. Antidepressants

Treat depression and mood disorders.
Examples: SSRIs (Fluoxetine), Tricyclics (Amitriptyline).

9. Antipsychotics

Manage psychotic conditions like schizophrenia.
Examples: Haloperidol, Risperidone.

10. Vaccines

Prevent diseases by stimulating immunity.
Examples: Polio vaccine, COVID-19 vaccines.

📊 Quick Comparison

Class	Purpose	Examples
Analgesics	Pain relief	Paracetamol, Morphine
Antibiotics	Kill bacteria	Penicillin, Ciprofloxacin
Antivirals	Fight viruses	Oseltamivir, Acyclovir
Antifungals	Treat fungi	Fluconazole, Clotrimazole
Antiparasitics	Kill parasites	Albendazole, Chloroquine
Antihypertensives	Lower BP	Beta-blockers, ACE inhibitors
Antidiabetics	Control sugar	Insulin, Metformin
Antidepressants	Mood disorders	Fluoxetine, Amitriptyline
Antipsychotics	Psychosis	Haloperidol, Risperidone
Vaccines	Prevent disease	Polio, COVID-19 vaccines

Medicines are divided into detailed therapeutic subclasses under the WHO’s Anatomical Therapeutic Chemical (ATC) system, which organizes drugs by organ system, therapeutic purpose, pharmacological action, and chemical structure. This hierarchy ensures global consistency in prescribing and research. WHO drugfyi.com medxdrg.com

🩺 Key Therapeutic Subclasses (Examples from ATC)

1. Cardiovascular Drugs

Antihypertensives → ACE inhibitors (Enalapril), Beta-blockers (Propranolol), Calcium channel blockers (Amlodipine).
Antiarrhythmics → Amiodarone, Lidocaine.
Diuretics → Thiazides (Hydrochlorothiazide), Loop diuretics (Furosemide).

2. Central Nervous System Drugs

Analgesics → NSAIDs (Ibuprofen), Opioids (Morphine).
Antidepressants → SSRIs (Fluoxetine), Tricyclics (Amitriptyline).
Antipsychotics → Typical (Haloperidol), Atypical (Risperidone).
Anxiolytics/Hypnotics → Benzodiazepines (Diazepam), Z-drugs (Zolpidem).

3. Anti-Infectives

Antibiotics → Penicillins, Cephalosporins, Macrolides, Fluoroquinolones.
Antivirals → Nucleoside analogues (Acyclovir), Protease inhibitors (Ritonavir).
Antifungals → Azoles (Fluconazole), Echinocandins (Caspofungin).
Antiparasitics → Antimalarials (Chloroquine, Artemisinin), Antihelminthics (Albendazole).

4. Endocrine & Metabolic Drugs

Antidiabetics → Insulin, Biguanides (Metformin), Sulfonylureas.
Thyroid drugs → Levothyroxine, Carbimazole.
Corticosteroids → Prednisolone, Dexamethasone.

5. Respiratory Drugs

Bronchodilators → Beta-2 agonists (Salbutamol), Anticholinergics (Ipratropium).
Anti-asthmatics → Leukotriene antagonists (Montelukast).
Antihistamines → Cetirizine, Loratadine.

6. Gastrointestinal Drugs

Antacids/Proton Pump Inhibitors → Omeprazole, Pantoprazole.
Antiemetics → Ondansetron, Metoclopramide.
Laxatives → Lactulose, Bisacodyl.

📊 Comparison Table of Subclasses

System	Subclass Examples	Representative Drugs
Cardiovascular	Antihypertensives, Antiarrhythmics, Diuretics	Enalapril, Amiodarone, Furosemide
CNS	Analgesics, Antidepressants, Antipsychotics	Ibuprofen, Fluoxetine, Risperidone
Anti-Infectives	Antibiotics, Antivirals, Antifungals	Penicillin, Acyclovir, Fluconazole
Endocrine	Antidiabetics, Thyroid drugs, Corticosteroids	Metformin, Levothyroxine, Prednisolone
Respiratory	Bronchodilators, Anti-asthmatics, Antihistamines	Salbutamol, Montelukast, Cetirizine
Gastrointestinal	PPIs, Antiemetics, Laxatives	Omeprazole, Ondansetron, Lactulose

⚠️ Key Considerations

Overlap exists: A drug may belong to multiple subclasses depending on indication (e.g., corticosteroids used in endocrine, respiratory, and dermatology).
India-specific regulation: Many of these subclasses fall under Schedule H/H1 for prescription-only use.
Global standardization: ATC codes ensure consistency in pharmacoepidemiology and drug utilization studies.

Would you like me to expand into ATC coding examples (like how Metformin is A10BA02) or keep the focus on clinical therapeutic subclasses for practical prescribing?

1. Antipyretics

Antipyretics are the substances which are used to reduce body temperature or to

control fever.

The word antipyretic is derived from pyro which means fire (means hot) anti

means against. Thus antipyretic means it counteracts heat (high body temperature).

Aspirin, paracetamol and phenacetin are commonly used antipyretics. You get

them in the market with different trade names like crocin, anacin, disprin, etc.

O CH3

COOH

NH-COCH3

OC2H5

NH-COCH3

Aspirin Paracetamol Phenacetin

Aspirin is the most popular antipyretic in use. It gets hydrolyzed in stomach and

salicylic acid is released. Overdose and using it over a long time may cause side

effects. It may cause bleeding in the stomach wall and even ulcers. Therefore,

overdose and prolonged use should be avoided. However, calcium and sodium salts

of aspirin are more soluble in water and are less harmful than aspirin.

2. Analgesics

Analgesics are the substances, that reduce pain which may be due to swelling of

tissues, injury, inflammation or some other disorders. Analgesics are of two types,

namely narcotic & non-narcotic.

Narcotic analgesics are the ones which induce sleep and thus help to reduce the

feeling of pain alkaloids present in opium, viz. morphine, codeine, etc. are common

examples of narcotics. In higher doses these may cause unconsciousness. These

are habit-forming and cause addiction. Due to addiction a person wants to have

it regularly and in larger amounts. Such a person feels upset and uncomfortable if

he doesnot get it. Narcotic analygesies do not induce sleep and are not habit

forming. A common example of this type of narcotics is morphine.

3. Antimalarials

Antimalarial medicines are used to treat malaria. Quinine and chloroquine are

widely used antimalarials. Quinine is one of the earliest drugs, which was first

obtained from the bark of a plant (cinchona) and later on synthesized in

laboratories.

CH3O

C H

CH2

Quinine

4. Antihistamines

Some persons are hypersensitive towards some medicines like penicillin, sulpha

drugs and may be sensitive to food and environment due to different sensitizing

substances (antigens) derived from them. The hypersensitivity is called allergy.

It is due to release of a chemical substance called histamine in the body.

“Anthistamine are the chemical substances (drugs) which control or abolish the

effect of histamines released in the body.” These drugs are also called antiallergic

drugs.

Histamine is also responsible for the nasal congestion (discharge), mild asthama

associated with common cold, cough, allergic response to pollengrains etc.

Histamine contract the smooth muscles in bronchi and gut, relaxes other muscles

present in the walls of fine blood versels. Antihistamine are widely used for

treatment of hay-fever, itching of eyes, nose and throat, conjuctivities. Some

antihistamine drugs are diphenhydramine (Benadryl) pheniramine maleate (Avil)

chlorspheniramine maleate (zect), citrazine and terfenadine (seldane)

5. Germicides, Disinfectant and Antiseptic

Germicides are the chemicals, which prevent growth of germs (microorganisms).

Germicides are classified as antiseptic and disinfectant. Both kill microorganisms

but the difference lies in the way we use them.

Antiseptics kill microorganisms and are safe to be used on living beings (tissues).

Antiseptics are used on wounds, cuts or skin abrasions. These are used to dress

wounds, etc. For example, iodoform (CHI3), tincture of iodine, ethyl alcohol,

a 0.2 percent aqueous solution of phenol and boric acid (H3BO3) are common

antiseptics.

Some dyes have the ability to kill microorganisms. These dyes were the earliest

compounds to be used as antiseptics. Examples are acriflavine (a yellow

coloured dye), mercurochrome (a red coloured dye), methylene blue (a blue

coloured dye). These dyes are still in use as antiseptics.

Iodine is a powerful antiseptic. It is used as tincture of iodine. Tincture of iodine

is 2 to 3 percent solution of iodine dissolved in ethyl alcohol. Iodoform is a

yellow coloured solid, which is used as an antiseptic.

Disinfectants kill germs (microorganisms) but are used on non-living substances

like surgical instruments, floors, bathrooms, lavatories, etc. Disinfectants are

harsh and are not safe to be used on living beings as disinfectants can damage

living tissues.

Chlorine is a powerful oxidizing agent. It is used for disinfecting water. A

concentration of 0.2 to 0.4 ppm (parts per million) is enough to kill microorganisms

present in water.

Low concentration of sulphur dioxide is used to kill microorganisms in jams,

jellies and squashes. Thus it acts as a food preservative. Sulphur dioxide is used

for fumigation in rooms, operation theaters, etc. to sterilize them. Bleaching

powder (CaOCl2), chlorine (Cl2), mercuric chloride (HgCl2), sodium hypochlorite

(NaClO), sulphur dioxide (SO2) etc. are other examples of disinfectants.

Is Phenol Antiseptic or Disinfectant?

It is interesting to note that 0.2 percent aqueous solution of phenol is used as antiseptic by making. It is safe to be used on living tissues in low concentrations (less than 0.2 percent). If concentration of phenol is high then it can damage tissues. Therefore, at higher concentration (1 percent or more) phenol is used

as disinfectant.

Most antiseptics and disinfectaints are powerful poisons (Table 30.2). They are able to kill microorganisms as they interfere with their metabolism. While some others are able to kill microorganisms because of their powerful oxidizing or reducing nature (Table 30.2).

6. Antacids

Antacids are the medicines which neutralize the excess acid present in the stomach.

Stomach juice contains hydrochloric acid (HCl). This acid helps the process of

digestion of food. Due to illness or anxiety or some other reasons more acid is

produced in the stomach. The stomach juice becomes more acidic than necessary.

This causes problems in digestion, bleeding in the lining of stomach or even ulcers.

Some medicines are used to neutrialise the excess acid and correct the pH of the

stomach fluid.

For example, sodium bicarbonate (NaHCO3) or a suspension of magnesium

hydroxide is used to neutralize excess of acid present in the stomach. Milk of

magnesia contains magnesium hydroxide, ‘ENO fruit salt’ contains sodium

bicarbonate which helps to neutralise excess acidity in the stomach juice. Medicine

like digene, gelusil, used as an antacid contain magnesium hydroxide.

7. Antimicrobials

Many diseases are caused due to infection in the body by certain microorganisms

(bacteria, fungus or viruses). Some examples of diseases caused by microbes are

dysentry, pneumonia, typhoid, urinary tract infection, etc.

Antimicrobials are the chemicals, which are used to kill microorganisms (which

has infected the body) without causing much damage to the body of the patient.

Thus an antimicrobial is a chemical, which is capable of curing diseases caused by

various microbes.

An ideal antimicrobial should kill disease-causing microbe and should not have

any harmful effect on the patient. In fact there may not be any such antimicrobial

which is totally safe and without any side effect.

The most common antimicrobials available are the sulhpa drugs and antibiotics.

8. Antibiotics

Antibiotics are the metabolic products produced by some microorganisms (mould

or fungi). They inhibit growth and even kill disease causing microorganisms (like

bacteria, fungi, etc) by inhibiting their life processes. Therefore they are referred

to as antibiotics (anti means against and biotic means life).

Penicillin was the first antibiotic to be discovered. Alexander Fleming isolated

penicillin in 1929 from a mould Pencillium notatum. Penicillin has been used

for the treating diseases caused by several bacteria. It has been effectively used

for treatment of pneumonia, bronchitis, sore throat, abscesses, etc.

Later on attempts have been made to improve the quality of penicillin. It has led

to the discovery of different varieties of penicillin. For example, Penicillin G (also

known as benzyl penicillin), penicillin F, penicillin K are the more common varieties

of penicillin.

COOH

S N

CH3

Penicillin G (benzyl penicllin)

Ampicillin and amoxicillin are the semi-synthetic modifications of penicillin. In

this case the metabolic product of mould is obtained and then some reactions

are carried out to bring the desired changes in the antibiotic molecule to get

ampicillin or amoxicillin.

Attempts are being made to discover better and better antibiotics. This search

for finding better antibiotics is a never-ending process. Now a large number of

antibiotics are available. Some examples are streptomycin and chloromycetin

(chloroamphenicol) and tetracycline.

CH2OH

N H

CO CHCl2

O2N

Chloroamphenicol

Streptomycin is used for the treatment of tuberculosis (TB). Chloromycetin is

used for the treatment of typhoid. Tetracycline is used for the treatment of several

diseases.

Broad-spectrum antibiotics are those antibiotics, which kill a wide range of diseasecausing

microorganisms.

Broad-spectrum antibiotics can be used for the treatment of several diseases. For

example, streptomycin, tetracycline and chloroamphenicol are broad-spectrum

antibiotics. Narrow spectrum antibiotics are effective in the treatment of a few

diseases.

9. Allergic Reactions of Antibiotics

Some people may show allergic reactions to some antibiotics. These reactions

may be mild like rashes appearing on the skin or may be very serious and can

even be fatal. You might have observed that a doctor gives a small dose of

antibiotic by injection and then waits for some time to watch if there is any

unwanted reaction. If there is no adverse (bad) reaction, then only the doctor

gives the full dose of the antibiotic.

10. Tranquilizers and Hypnotics

Tranquilizers and hypnotics are used to reduce anxiety, and they also make a

person calm. Sleeping pills are made up of these compounds. Most of them are

habit-forming. Their indiscriminate and over use should be avoided. Otherwise it

may lead to addiction and many other complications,

O O

CH3

H7C3

O O

H5C2

Luminal Seconal

Luminal, seconal and equanil are the most commonly used tranquilizers. Barbituric

acid and some other compounds related to barbituric acid are used in making

sleeping pills.

O O

H N 2 O O NH2

CH3

Barbituric acid Equanil

11. Fertility Control Medicines

It is a concern of everyone to control human population. Medicines are available

which help prevent pregnancy. The medicines, which help prevent pregnancy, are

known as contraceptives. These are generally available in the form of tablets and

are to be taken regularly by females. Chemicals like norethindrone and mestranol

are used as contraceptives (birth control pills). Chemically these are similar to

female sex hormones.

Norethindrone

Mestranol

The birth control pills may have some side effects in some cases. Therefore,

the birth control pills should be used under the guidance of some expert.

INTEXT QUESTIONS 30. 2

30.3 HAZARDS OF SELF MEDICATION

When medicines are taken by a patient without the advice of a qualified doctor, it is called self-mediation.

Self-medication is very harmful and a dangerous practice. One should never try self-medication. Some of the harmful effects are:

1. A medicine, which has worked well for some one, may not be good for you and can even cause some serious harm.

2. You may take a medicine in quantity more than necessary. It may be harmful for you.

3. You may take quantity less than necessary. The disease-causing microorganisms may gain resistance to the medicine and the medicine may become ineffective.

You should avoid self-medication. Without advice of a doctor avoid use of common medicines over prolong periods. Improper use of even most common medicines, which are readily available without a prescription of a doctor, can have harmful effect.

The medicines, which you can buy without a prescription of a doctor, are called over-the-counter medicines. For example cough syrups, crocin, aspirin, etc are over the counter medicines.

The medicines, which you can buy after showing a prescription of a qualified doctor, are known as scheduled drugs. Improper use of scheduled drugs is likely to cause more serious problems. Therefore, their sale is controlled and regulated by the government.

Most of good chemists do not sell scheduled medicines without a proper prescription. Some irresponsible chemists may sell such medicines without a prescription. It is not a good practice you should not encourage it.

INTEXT QUESTIONS 30.3

1. Give two examples of antipyretics. 1. Aspirin and Paracetamol

2. Give one example of a narcotic type analgesic. - Morphine.

3. What is the difference between an antiseptic and disinfectant?

Disinfectants kill germs but can damage living tissues Anticeptics are safe

for living tissues and yet kill germs.

4. What are antacids? Name two chemicals commonly used as antacids.

Medicines used to neutralise excess acid in the stomach. Magnesium hydroxides and sodium carbonate.

5. What is the difference between local anaesthetic and general anaesthetic.

Local anesthetics cause loss of sensation of pain over a small area while general anesthetics cause loss of concsiousness.

6. Define antibiotics. Give one example of an antibiotic.

Metabolic products of certain microorganisms and can kill some other microorganisms. Penicilin is an example of antibiotic.

7. Which type of medicines are usd in hey-fever, itching of eyes; nose and throuts.

Anti histomines are used.

8. What is the use of tranquilizers and hypnotics?

Tranquilizers and hypnotics are used to reduce anxiety and these also make a person calm.

9. Give one example of a tranquilizer. luminal

10. What are contraceptives?

Contraceptives are the medicines used for prevention of pregnancy.

11. What are over the counter medicines?

Over-the-counter medicines are those which can be purchased without a prescription from a doctor.

30.3.1 Chemicals in foods – Preservatives and artificial sweetening agents

Food Preservatives: “Chemical substances which are used to protect food materials against microorganisms (bacteria yeasts and moulds) are called preservatives.”

Some commonly used preservatives are

1. Common Salt, Sugar and oils: The sufficient amount of salt resist the activity of microorganisms in food it is called salting. It is used to preserve raw mango, bean, fish and meat, etc. Sugar syrup used for preserving like apple, mango, amla and carrot etc. Sugar, oil, vinegar & citric acid are used to preserve pickles, ketchups and jams, etc.

2. Sodium benzoate (C6H5COONa): It is used for preserving of food material like fruit juices, soft drinks, squashes and jams. It is soluble in water. It is metabolized as hippuric and which is excreted in urine.

3. Sodium meta bisulphite (Na2S2O5): Its preservative action is due to SO2 which from sulphurous acid when dissolved in water. It also inhibits the growth of yeasts, moulds and bacteria. It is used to preserve fruitams, juices, squashes, pickles, apples, etc.

4. Sodium and Potassium Salts of propionic acid, sorbic acid are also used as preservatives.

30.3.2 Antioxidants

The unsaturated fat and oils are readily oxidized on storage, the taste and smell are changed and become rancid. To prevent this oxidation, rancidity and spoilage, certain chemical substances are added, are called antioxidant (food additives).

When these are added to food items containing fats and oils retard the oxidation because they are more reactive towards oxidation than fats and oils. So the oxidation of food is prevented. Antioxidants react with free radicals and stop the oxidation of food. The most familiar antioxidants are butylated hydroxyl toluene (BHT) and butylated hydroxyl anisole (BHA)

OCH3

C(CH3)3

CH3

C(CH3)3

(CH3)C

(BHA) (BHT)

C(CH3)3C

These are added to butter, meats, cereals chewing gum, snack gum, baked food and beer etc. It increases the life of food from months to years. It shows more active synergetic effect when added with Vitamin C (ascorbic acid) and citric acid.

30.2.3 Artificial Sweetening Agents

“The chemical compounds which give sweetening effect to the food are called sweeting agent.” Sucrose and Glucose are widely used as natural sweetening agent. The excess intake of natural sugar cause to obesity diabetics and tooth decay. Natural sugar is a good source of energy. While the artificial sweetening agents does not provide energy. It is excreted from the body in urine unchanged.

Some commonly used artificial sweetening agents are saccharin, aspartame, alitame, sucrolose, etc.

1. Saccharin (O-Sulpho benzimide) Saccharin is insoluble in water but sodium salt is highly soluble in water. It is 550 times sweeter than sugar. It is not metabolized by our body. So it does not provide energy and has no calorific values.

SO2

Saccharine

(Insoluble inwater)

N – Na

SO2

– +

Sodium salt of

Saccharine

(Solube in water)

2. Aspartame – It is methyl ester of dipetide derivative derived from aspartic acid and phenylalanine. It is 100 times as sweet as sugar. It is unstable at cooking temperatures. It is used in cold drinks and soft drinks. It is an exception because the body breakes it down in to amino acid and menthol.

HO — CCH2 — CH — C — NH — CH — C — OCH3

O O O

NH2 CH2

(Aspartame)

3. Alitame: It is very high potency sweetener, It is about 2000 times sweeter than sugar. It is more stable at cooking temperatures. It is very difficult to control the sweetness of food.

4. Sucrolose: It is trichloro derivative of sucrose. It’s taste is like sugar. It is also stable at cooking temperatures. It is about 600 times sweeter than sugar.

Sucrolose is expected to become a great commercial artificial sweeting agent.

INTEXT QUESTIONS 30.3

1. What type of change take place on storage the fat & oil?

On storage of fat and oil get oxidised, the taste and smell are changed and become rancid.

2. Write the name of preservative used with soft drinks.

Sodium benzoate (C6H5COONa) is used as perservative with soft drinks.

3. What change will take inner body on taking exercise sugar (N).

The excess intake of natural sugar cause to obesity and tooth decay.

WHAT YOU HAVE LEARNT

􀁺 Medicines are the chemicals or mixture of chemicals used for the prevention, cure, treatment, management of diseases and disorders or recovery of patients

􀁺 Medicines are obtained from plants or parts of plants or synthesized in laboratories.

􀁺 Medicines may contain only one chemical compound or it may be a mixture of several compounds.

􀁺 Drugs may be the crude mixtures and the identity of all the chemical

components and their amount present in them may not be accurately known.

􀁺 Antipyretics are used to reduce body temperature for example aspirin and paracetamol.

􀁺 Analgesics reduce body pain for example aspirin and morphine.

􀁺 Antiseptics kill microorganisms and are safe to be used on a living tissue while disinfectants are used on inanimate objects.

􀁺 Aqueous solution (less than 0.2 percent) of phenol is used as an antiseptic.

In higher concentrations phenol is used as a disinfectant.

􀁺 Antibiotics are the metabolic products produced by certain microorganisms which can kill some microorganisms. For example penicillin, streptomycin, tetracycline, etc.

􀁺 Broad spectrum antibiotics can kill several different microorganisms, therefore, can cure several diseases.

􀁺 On storage the taste and smell are changed and become rancid.

􀁺 Certain chemical substances are added to control oxidation spoilage and rancidity.

􀁺 Butylated hydroxyl toluene (BHT) and Butylated hydroxyl anisole (BHA).

􀁺 Common Salt, sugar and oils are natural food preservatives.

􀁺 Sodium benzrate is familiar food predervative.

􀁺 Aspartame is unstable at cooking temp. so used in cold drinks and soft drinks.

􀁺 Alitame is more stable at cooking temp.

􀁺 Suerolose is mare stable at cooling tamp and easy to control the sweetness of food.

TERMINAL EXERCISE

1. How are medicines classified?

Medicines are classified in multiple ways — by their chemical structure, therapeutic use, mechanism of action, organ system affected, and legal/regulatory status. Globally, the WHO’s ATC system is widely used, while in India, drugs are also grouped under schedules like H, H1, and X for regulation.

🔑 Major Systems of Medicine Classification

1. Therapeutic Use

Groups medicines by the disease or symptom they treat.
Examples:
- Analgesics → pain relief
- Antibiotics → infections
- Antihypertensives → high blood pressure

2. Chemical Structure

Based on the molecular composition of drugs.
Examples: alkaloids, steroids, glycosides.
Useful for research and understanding drug relationships.

3. Mechanism of Action

Focuses on how a drug works at the cellular or receptor level.
Example: Calcium channel blockers act on heart/blood vessels.
Preferred in modern pharmacology and drug development.

4. Organ System

Categorizes drugs by the body system they affect.
Examples: Cardiovascular drugs, respiratory drugs, nervous system drugs.

5. ATC System (WHO Standard)

Five-level hierarchy:
- Level 1 → Organ/system (e.g., cardiovascular)
- Level 2 → Pharmacological subgroup
- Level 3 & 4 → Chemical/therapeutic subgroup
- Level 5 → Specific chemical substance
Example: Metformin → A10BA02 (antidiabetic drug).

6. Legal/Regulatory Classification (India Specific)

Under the Drugs and Cosmetics Act, 1940:
- Schedule H → Prescription-only drugs
- Schedule H1 → Antibiotics with stricter control
- Schedule X → Narcotics/psychotropics with high misuse potential
Controlled substances regulated by the NDPS Act, 1985.

📊 Comparison Table

Classification Type	Basis	Example	Usefulness
Therapeutic	Disease/symptom treated	Antibiotics	Clinical practice
Chemical	Molecular structure	Steroids	Research/chemistry
Mechanism of Action	Biological target	Beta-blockers	Pharmacology & R&D
Organ System	Body system affected	Respiratory drugs	Teaching/clinical
ATC (WHO)	Multi-level hierarchy	Metformin A10BA02	Global standard
Legal/Regulatory	Law & safety	Schedule H drugs	Regulation & safety

⚠️ Challenges & Limitations

Overlap: Many drugs fit into multiple categories (e.g., caffeine is both a stimulant and diuretic).
Global Variability: Classification differs across countries.
Evolving Systems: Modern pharmacology increasingly favors mechanism-based classification.

2. Who isolated the first antibiotic?

The first antibiotic, penicillin, was isolated by Sir Alexander Fleming in 1928 from the mould Penicillium rubens while working at St. Mary’s Hospital in London. His discovery marked the beginning of modern antibiotic therapy and earned him, along with Howard Florey and Ernst Chain, the Nobel Prize in Physiology or Medicine in 1945. en.wikipedia.org Wikipedia en.wikipedia.org NobelPrize.org

🧪 Key Details of the Discovery

Year of discovery: 1928
Scientist: Sir Alexander Fleming, Scottish physician and microbiologist
Location: St. Mary’s Hospital, London
Substance: Penicillin (benzylpenicillin, later called penicillin G)
Observation: A mould contaminating a Staphylococcus aureus culture produced a clear zone where bacteria could not grow.
Impact: Penicillin became the first true antibiotic used to treat bacterial infections effectively.

👨‍🔬 Development After Fleming

Fleming’s initial work showed penicillin’s antibacterial properties but he struggled with purification and large-scale production.
In 1939, a team at Oxford led by Howard Florey and Ernst Chain developed methods to extract, purify, and mass-produce penicillin.
By World War II, penicillin was being produced in large quantities, saving thousands of soldiers from infections.

📊 Timeline of Antibiotic Milestones

Year	Scientist(s)	Discovery	Significance
1928	Alexander Fleming	Penicillin	First antibiotic isolated
1939–1941	Howard Florey & Ernst Chain	Penicillin purification	Enabled clinical use
1940s	Selman Waksman	Streptomycin	First antibiotic against tuberculosis
1950s–60s	Multiple researchers	Tetracyclines, macrolides	Broadened antibiotic spectrum

⚠️ Challenges & Legacy

Fleming himself warned about antibiotic resistance as early as the 1940s.
His discovery revolutionized medicine, turning once-deadly infections into treatable conditions.
Today, penicillin remains a cornerstone of antimicrobial therapy, though resistance has reduced its effectiveness against some bacteria.

3. Name a medicine, which is used as analgesic as well as antipyretic.

A widely used medicine that works both as an analgesic (pain reliever) and antipyretic (fever reducer) is Paracetamol (also called Acetaminophen). It is considered safe for most people, including children and pregnant women, when taken at recommended doses.

Common Analgesic + Antipyretic Medicines

Here are the most frequently used drugs that serve both purposes:

Medicine	Analgesic Use	Antipyretic Use	Notes
Paracetamol	Relieves mild to moderate pain (headache, toothache, muscle pain)	Reduces fever effectively	Safe in pregnancy and children; overdose can cause liver damage
Ibuprofen	Pain relief (muscle aches, arthritis, menstrual cramps)	Lowers fever	Also anti-inflammatory; may irritate stomach lining
Aspirin	Pain relief (headache, joint pain)	Reduces fever	Not recommended for children (risk of Reye’s syndrome); also used as blood thinner

Key Points

Paracetamol is the most commonly recommended option for both pain and fever, especially in India, due to its safety profile.
Ibuprofen is useful when inflammation is also present (e.g., arthritis, muscle injury).
Aspirin is less commonly used today for fever in children, but still prescribed for certain adult conditions.

Risks & Precautions

Paracetamol overdose can cause severe liver damage.
Ibuprofen and aspirin may cause stomach irritation, ulcers, or kidney issues if taken long-term or in high doses.
Always follow doctor’s advice and recommended dosage instructions

4. What is a non-narcotic analgesic?

A non-narcotic analgesic is a pain-relieving medicine that does not belong to the opioid (narcotic) class. These drugs relieve mild to moderate pain and often reduce fever or inflammation, without causing dependence or sedation. Common examples include paracetamol (acetaminophen) and NSAIDs like ibuprofen or aspirin.

🔎 Definition

Non-narcotic analgesic: A medication that relieves pain without acting on opioid receptors and without causing loss of consciousness.
They are also called non-opioid analgesics.
Typically used for headaches, muscle pain, arthritis, fever, and minor injuries. Medical Dictionary pressbooks.openeducationalberta.ca

🧪 Types of Non-Narcotic Analgesics

Drug Class	Examples	Key Actions	Risks/Notes
Paracetamol	Acetaminophen (Tylenol, Crocin)	Analgesic + antipyretic	Safe at normal doses; overdose → liver damage
NSAIDs	Ibuprofen, Naproxen, Aspirin	Analgesic + antipyretic + anti-inflammatory	Can irritate stomach, increase bleeding risk
COX-2 inhibitors	Celecoxib	Pain + inflammation relief	Lower stomach risk, but may increase heart risk

✅ Advantages

Non-addictive (unlike opioids).
Widely available over-the-counter (OTC).
Effective for mild to moderate pain.
Often cheaper and safer for long-term use compared to narcotics.

⚠️ Risks & Precautions

Paracetamol: Overdose can cause severe liver failure.
NSAIDs: Long-term use may cause stomach ulcers, kidney damage, or increase risk of heart attack/stroke.
Should be used under medical guidance for chronic conditions.

📍 Context for India (Guindy, TN)

Paracetamol (Crocin, Dolo-650) is the most commonly prescribed non-narcotic analgesic for fever and pain.
Ibuprofen (Brufen) and Aspirin are also widely available in pharmacies.
These are OTC medicines, but dosage should be carefully followed.

5. Why is 2.0 percent aqueous solution of phenol used as a disinfectant?

A 2.0% aqueous solution of phenol is used as a disinfectant because at this concentration it effectively kills many bacteria, fungi, and some viruses by denaturing their proteins and disrupting cell membranes, while remaining stable and safe enough for controlled use.

🔬 Why Phenol Works as a Disinfectant

Protein denaturation: Phenol coagulates and denatures microbial proteins, leading to cell death.
Membrane disruption: It damages the lipid membranes of microorganisms, causing leakage of essential cell contents.
Broad-spectrum activity: Effective against Gram-positive and Gram-negative bacteria, fungi, and some viruses.

⚖️ Why 2.0% Concentration is Used

Effective balance: At 2% concentration, phenol is strong enough to kill microbes but not excessively corrosive.
Safety margin: Higher concentrations (>5%) are too caustic and can damage skin or surfaces.
Standardization: 2% phenol solution has historically been used as a benchmark in the Rideal–Walker test to measure disinfectant potency.

🧪 Applications

Hospital disinfection: Used for cleaning contaminated surfaces and instruments.
Laboratory use: Applied in microbiology labs for decontamination.
Household products (historically): Early antiseptics and disinfectants contained phenolic compounds.

⚠️ Risks & Precautions

Toxicity: Phenol is corrosive and can cause burns; prolonged exposure may lead to systemic toxicity.
Environmental hazard: Phenol residues can be harmful if not disposed of properly.
Safer alternatives: Modern disinfectants (like quaternary ammonium compounds, alcohols, and chlorine solutions) are often preferred due to lower toxicity.

📍 Context for India (Guindy, TN)

Phenolic disinfectants are still used in hospital cleaning protocols and industrial sanitation.
Commonly available commercial phenolic disinfectants include Lysol-type products and Vesphene formulations.
For household use, bleach (sodium hypochlorite) or alcohol-based sanitizers are safer alternatives.

6. What do you understand by allergic reactions of antibiotics?

Allergic reactions to antibiotics occur when the immune system mistakenly identifies the drug as harmful and overreacts, leading to symptoms ranging from mild rashes to life-threatening anaphylaxis. Penicillins and sulfa drugs are the most common culprits, and reactions can be immediate (within hours) or delayed (days after starting treatment).

🔬 What Are Antibiotic Allergic Reactions?

Drug allergy: An immune-mediated hypersensitivity reaction to an antibiotic.
Not the same as side effects: Side effects (like nausea or diarrhea) are common but not immune-related. Allergic reactions involve the immune system.
Prevalence: About 10% of people report antibiotic allergies, but fewer than 1% have true immune-mediated reactions.

⚠️ Symptoms of Allergic Reactions

Immediate Reactions (within minutes–hours)

Hives or itchy rash
Facial swelling (lips, tongue, throat)
Wheezing or difficulty breathing
Throat tightness, rapid heartbeat, dizziness
Anaphylaxis (life-threatening reaction requiring epinephrine) GoodRx

Delayed Reactions (days after starting)

Maculopapular rash (flat, red patches)
Fever, joint pain, swollen lymph nodes
Skin peeling or severe itching heyallergy.com

🧪 Common Antibiotics That Cause Allergies

Antibiotic	Risk Level	Notes
Penicillins	Most common	Cross-reactivity with cephalosporins possible
Sulfa drugs	Second most common	Higher risk in HIV/AIDS patients
Cephalosporins	Less common	May cross-react with penicillins

🚨 Emergency Warning Signs

Seek immediate medical care if you experience:

Severe difficulty breathing
Rapid pulse or dizziness
Confusion or loss of consciousness
Extensive swelling of face or throat

✅ Management & Prevention

Stop the antibiotic immediately if allergy is suspected.
Contact a doctor for evaluation and alternative treatment.
Treatment options: Antihistamines (mild), corticosteroids (moderate), epinephrine (severe).
Future care: Allergy testing, medical alert bracelet, and documentation of the reaction.

Penicillin and sulfa allergies are frequently reported in local hospitals.
Doctors often switch to macrolides (azithromycin, clarithromycin) or fluoroquinolones if allergy is confirmed.
Patients are advised to carry written records of their allergy for safe prescribing.

7. What are scheduled drugs?

Scheduled drugs are medicines that are classified and regulated under specific schedules (categories) in drug laws, based on their potential for abuse, medical use, and safety risks. The term comes from the Drug Scheduling System used in many countries, including India and the United States, to control how certain drugs are prescribed, dispensed, and monitored.

🔎 What Scheduled Drugs Mean

Scheduled drugs: Medications placed into legal categories (Schedules) according to their risk of misuse and therapeutic value.
Purpose: To prevent abuse, ensure safe medical use, and regulate distribution.
Authority: In India, governed by the Drugs and Cosmetics Act and Narcotic Drugs and Psychotropic Substances Act (NDPS Act). In the US, regulated by the Controlled Substances Act.

📋 Examples of Drug Schedules

India (NDPS Act & Drugs Rules)

Schedule H: Prescription-only drugs (e.g., antibiotics, antidepressants).
Schedule X: High-risk drugs (e.g., narcotics, psychotropics) — stricter control.
Schedule G: Drugs requiring medical supervision (e.g., hormonal medicines).

United States (Controlled Substances Act)

Schedule I: No accepted medical use, high abuse risk (e.g., heroin, LSD).
Schedule II: Medical use but high abuse potential (e.g., morphine, cocaine).
Schedule III–V: Lower abuse risk, accepted medical use (e.g., codeine combinations, benzodiazepines).

⚠️ Why Scheduling Matters

Controls misuse of addictive substances.
Guides doctors on prescribing safely.
Protects patients from self-medication risks.
Legal consequences: Unauthorized possession or sale of scheduled drugs can lead to fines or imprisonment.

📍 Context in India (Mylapore, TN)

Pharmacies must maintain prescription records for Schedule H and X drugs.
Common antibiotics (like amoxicillin) fall under Schedule H.
Strong painkillers (like morphine) are under Schedule X and require strict documentation.
Over-the-counter drugs (like paracetamol) are not scheduled.

8. Which medicines can you purchase without the prescription from a doctor?

Medicines you can purchase without a doctor’s prescription are called Over-the-Counter (OTC) drugs. These are considered safe for self-use when taken in recommended doses, and they usually treat minor, everyday health issues.

📋 Common OTC Medicines (India context)

Category	Examples	Uses
Pain & fever relief	Paracetamol (Crocin, Dolo-650), Ibuprofen (Brufen)	Headache, mild pain, fever
Cold & allergy	Antihistamines (Cetirizine, Loratadine), Decongestants (Pseudoephedrine)	Sneezing, runny nose, nasal congestion
Digestive health	Antacids (Eno, Gelusil), Loperamide, Oral rehydration salts (ORS)	Acidity, diarrhea, dehydration
Skin care	Calamine lotion, Antifungal creams (Clotrimazole), Antiseptic ointments	Rashes, fungal infections, minor cuts
Vitamins & supplements	Multivitamins, Vitamin C, Iron & Calcium tablets	General health, nutritional support

⚠️ Important Notes

Antibiotics are NOT OTC: In India, antibiotics fall under Schedule H and require a doctor’s prescription.
OTC ≠ risk-free: Even OTC drugs can cause side effects or interact with other medicines.
Dosage matters: Overuse of paracetamol, for example, can cause liver damage.
Local pharmacy rules: Some pharmacies may still sell prescription drugs without proper checks, but this is unsafe and illegal.

📍 Everyday Examples

For a fever or headache, you can buy paracetamol.
For seasonal allergies, cetirizine is commonly available.
For acidity, Gelusil or Eno are OTC options.
For minor cuts, antiseptic creams like Betadine or Savlon are used.

9. What is self-medication? Describe some of its ill effects.

Self-medication means using medicines on your own — without consulting a doctor — to treat perceived health problems. It often involves buying OTC drugs or even prescription medicines directly from pharmacies, based on past experience, advice from friends, or online information. While it may seem convenient, it carries significant risks.

⚠️ Ill Effects of Self-Medication

Wrong diagnosis: You may treat symptoms without knowing the actual disease, delaying proper care.
Drug resistance: Misuse of antibiotics can lead to resistant bacteria, making infections harder to treat.
Side effects: Medicines can cause nausea, rashes, or even organ damage if taken incorrectly.
Masking serious illness: Painkillers may hide symptoms of conditions like appendicitis or cancer, delaying diagnosis.
Drug interactions: Combining medicines without guidance can cause harmful reactions.
Addiction risk: Sedatives, painkillers, or cough syrups can be habit-forming if misused.

📍 Context in India (Mylapore, TN)

Pharmacies often sell antibiotics and painkillers without strict prescription checks.
Many people self-medicate for fever, cough, and stomach issues, but this increases risks of antibiotic resistance and drug misuse.
Public health campaigns emphasize consulting doctors instead of relying on self-treatment.

✅ Safer Practices

Use only OTC medicines for minor issues (like paracetamol for fever).
For persistent or severe symptoms, consult a doctor.
Avoid using antibiotics, steroids, or sedatives without prescription.
Keep a record of medicines taken to avoid duplication or overdose.

10. Write the two names of chemicals which increases the life of food from months to years.

Self-medication means taking medicines without consulting a doctor — relying on past experience, advice from friends, or information from the internet/pharmacy. While it may seem convenient, it can be dangerous because medicines are powerful chemicals that need proper diagnosis and dosage.

⚠️ Ill Effects of Self-Medication

Wrong diagnosis: Treating symptoms without knowing the actual disease can delay proper treatment.
Antibiotic resistance: Misusing antibiotics makes bacteria resistant, leading to infections that are harder to cure.
Side effects: Medicines can cause nausea, rashes, or even organ damage if taken incorrectly.
Masking serious illness: Painkillers may hide symptoms of appendicitis, ulcers, or cancer, delaying diagnosis.
Drug interactions: Combining medicines without guidance can cause harmful reactions.
Addiction risk: Sedatives, painkillers, or cough syrups can be habit-forming if misused.

📍 Context in India (Mylapore, TN)

Pharmacies often sell antibiotics and painkillers without strict prescription checks.
Many people self-medicate for fever, cough, stomach upset, but this increases risks of drug resistance and misuse.
Public health campaigns emphasize consulting doctors instead of relying on self-treatment.

✅ Safer Practices

Use only OTC medicines for minor issues (like paracetamol for fever).
For persistent or severe symptoms, consult a doctor.
Avoid using antibiotics, steroids, or sedatives without prescription.
Keep a record of medicines taken to avoid duplication or overdose.

11. Which artificial sweatening agents is more suitable at cooking temperatures.

Artificial sweetening agents differ in their stability at high temperatures. Some break down when heated, while others remain stable and can be safely used in cooking or baking.

🍬 Suitable Artificial Sweeteners for Cooking

Sucralose
- Highly heat-stable.
- Can be used in baking, boiling, and frying without losing sweetness.
- Commonly marketed as Splenda.
Saccharin
- Fairly stable at cooking temperatures.
- Used in baked goods and processed foods.
- Has a slightly bitter aftertaste at high concentrations.

❌ Less Suitable for Cooking

Aspartame: Breaks down at high temperatures, losing sweetness — best for cold foods and drinks.
Stevia: Natural sweetener, moderately heat-stable, but can develop a bitter taste when overheated.

📍 Context in India (Mambalam, TN)

Sucralose is widely available in sugar-free baking mixes and diabetic-friendly products.
Saccharin is found in tabletop sweeteners and processed foods.
Aspartame is common in diet sodas but not recommended for cooking.

👉 In summary: Sucralose is the most suitable artificial sweetener for cooking and baking, while saccharin can also be used but with some taste limitations.

12. Which is responsible for perservation action of sodium meta bisulphite?

The preservative action of sodium metabisulphite is mainly due to the release of sulfur dioxide (SO₂), which acts as an antimicrobial agent and antioxidant, inhibiting microbial growth and preventing oxidation in foods. It also prevents enzymatic browning in fruits and vegetables by inhibiting polyphenol oxidase. vinipulchemicals.com pdf.benchchem.com tianyachemical.com

How Sodium Metabisulphite Works

Sulfur dioxide release
In aqueous solutions, sodium metabisulphite liberates SO₂, which forms sulfurous acid. This disrupts microbial enzymatic activity and metabolic pathways, effectively killing or inhibiting bacteria, yeasts, and molds.
Antioxidant properties
It scavenges oxygen, slowing down oxidative reactions that cause spoilage. This helps maintain flavor, color, and texture in foods.
Enzymatic inhibition
It prevents enzymatic browning in fruits and vegetables by inhibiting polyphenol oxidase, keeping produce visually appealing and fresh.
Antimicrobial activity
Effective against a wide range of microorganisms, including molds and yeasts, ensuring food safety and longer shelf life.

Applications in Food Preservation

Wine and beer
Prevents oxidation and microbial spoilage, stabilizing the product.
Fruit and vegetable processing
Maintains color, texture, and nutritional value in canned, frozen, and dried products.
Pharmaceuticals
Used as a preservative to prevent degradation of sensitive compounds.

Key Takeaway

The preservation action of sodium metabisulphite is primarily due to SO₂ release, which provides antimicrobial protection, antioxidant effects, and enzymatic inhibition. This makes it a versatile preservative across food, beverage, and pharmaceutical industries.

Medicines are grouped into classes of drugs based on their therapeutic use, mechanism of action, or chemical nature. Here’s a structured overview:

🩺 Broad Classes of Drugs

1. Analgesics

Relieve pain.
Subclasses:
- NSAIDs (Ibuprofen, Aspirin)
- Opioids (Morphine, Codeine)

2. Antibiotics

Kill or inhibit bacteria.
Subclasses:
- Penicillins (Amoxicillin)
- Cephalosporins (Ceftriaxone)
- Macrolides (Azithromycin)

3. Antivirals

Target viral infections.
Subclasses:
- Nucleoside analogues (Acyclovir)
- Protease inhibitors (Ritonavir)

4. Antifungals

Treat fungal infections.
Subclasses:
- Azoles (Fluconazole)
- Echinocandins (Caspofungin)

5. Antiparasitics

Act against parasites.
Subclasses:
- Antimalarials (Chloroquine, Artemisinin)
- Antihelminthics (Albendazole)

6. Cardiovascular Drugs

Affect the heart and blood vessels.
Subclasses:
- Antihypertensives (Beta-blockers, ACE inhibitors)
- Antiarrhythmics (Amiodarone)
- Diuretics (Furosemide)

7. Endocrine Drugs

Influence hormones and metabolism.
Subclasses:
- Antidiabetics (Insulin, Metformin)
- Thyroid drugs (Levothyroxine)
- Corticosteroids (Prednisolone)

8. CNS Drugs

Act on the brain and nervous system.
Subclasses:
- Antidepressants (SSRIs, Tricyclics)
- Antipsychotics (Haloperidol, Risperidone)
- Anxiolytics (Diazepam)

9. Respiratory Drugs

Used for asthma, COPD, allergies.
Subclasses:
- Bronchodilators (Salbutamol)
- Antihistamines (Cetirizine)

10. Gastrointestinal Drugs

Act on the digestive system.
Subclasses:
- Proton Pump Inhibitors (Omeprazole)
- Antiemetics (Ondansetron)
- Laxatives (Lactulose)

11. Vaccines

Prevent diseases by stimulating immunity.
Examples: Polio vaccine, COVID-19 vaccines.

📊 Quick Comparison

Class	Subclasses	Examples
Analgesics	NSAIDs, Opioids	Ibuprofen, Morphine
Antibiotics	Penicillins, Cephalosporins	Amoxicillin, Ceftriaxone
Antivirals	Nucleoside analogues, Protease inhibitors	Acyclovir, Ritonavir
Antifungals	Azoles, Echinocandins	Fluconazole, Caspofungin
Antiparasitics	Antimalarials, Antihelminthics	Chloroquine, Albendazole
Cardiovascular	Antihypertensives, Diuretics	Enalapril, Furosemide
Endocrine	Antidiabetics, Corticosteroids	Metformin, Prednisolone
CNS	Antidepressants, Antipsychotics	Fluoxetine, Risperidone
Respiratory	Bronchodilators, Antihistamines	Salbutamol, Cetirizine
Gastrointestinal	PPIs, Antiemetics	Omeprazole, Ondansetron
Vaccines	Preventive	Polio, COVID-19 vaccines

Would you like me to go deeper into pharmacological subclasses (mechanism-based, like beta-blockers, SSRIs, PPIs) or keep the focus on therapeutic subclasses (disease-based, like antibiotics, antidiabetics)?

The terms drugs and medicines are often used interchangeably, but they have distinct meanings in pharmacology and healthcare.

⚖️ Key Differences Between Drugs and Medicines

Aspect	Drugs	Medicines
Definition	Any chemical substance that affects the body’s physiological functions. Can be natural, synthetic, or semi-synthetic.	A drug that has been formulated, tested, and approved for therapeutic use to prevent, treat, or cure disease.
Scope	Broader — includes recreational drugs, toxic substances, and chemicals with biological activity.	Narrower — only those drugs used for medical treatment and patient care.
Regulation	May or may not be regulated (e.g., caffeine, nicotine, narcotics).	Strictly regulated by health authorities (FDA, WHO, CDSCO in India).
Purpose	Can alter mood, perception, or physiology — not always for health.	Specifically intended to improve health, relieve symptoms, or cure illness.
Examples	Cocaine, LSD, caffeine, morphine.	Paracetamol (pain relief), Amoxicillin (antibiotic), Insulin (diabetes).

🧩 Simple Way to Remember

Drug → Any biologically active substance.
Medicine → A drug that is safe, effective, and approved for treating disease.

So, all medicines are drugs, but not all drugs are medicines.

🌍 Visual Illustration

Here’s a conceptual way to picture it:

Drugs = Big circle (all substances affecting the body).
Medicines = Smaller circle inside (only those approved for therapy).

Would you like me to expand into examples of drugs that are not medicines (like recreational or toxic substances) or focus on examples of medicines derived from drugs (like morphine → painkiller, penicillin → antibiotic)?

Here’s your diagrammatic infographic on the classes of medicines — it’s ready now:

https://copilot.microsoft.com/th/id/BCO.e03d3cdd-906b-406d-9184-7e84ccbc3945.png

This circular infographic highlights the major classes of medicines (Analgesics, Antibiotics, Antivirals, Antifungals, Antiparasitics, Cardiovascular drugs, Antidiabetics, CNS drugs, Respiratory drugs, and Vaccines), with icons and examples for each.

Would you like me to create a therapeutic subclasses infographic (e.g., NSAIDs, SSRIs, PPIs) or a regulatory classification infographic (Schedules H, H1, X in India)?

Here are your dual infographics — one showing therapeutic subclasses of medicines and the other illustrating regulatory classifications in India.

The first chart organizes medicines by clinical purpose (NSAIDs, antibiotics, antidiabetics, CNS drugs, cardiovascular drugs, antivirals, antifungals, etc.), while the second explains Schedules H, H1, and X under the Drugs and Cosmetics Act and NDPS Act, 1985, highlighting prescription control and abuse risk.

These visuals make it easy to compare both the medical and legal perspectives of drug classification.

Antibiotic resistance occurs when bacteria evolve to withstand the effects of antibiotics, making infections harder or sometimes impossible to treat. It is driven mainly by misuse and overuse of antibiotics in humans, animals, and agriculture, and is now considered one of the biggest global public health threats.

🧬 What Is Antibiotic Resistance?

Definition: Bacteria change genetically so that antibiotics can no longer kill them or stop their growth.
Key Point: It is the bacteria that become resistant, not the human body.
Result: Common infections like urinary tract infections, pneumonia, or tuberculosis become difficult to treat.

⚠️ Causes and Drivers

Overuse of antibiotics: Prescribing or taking antibiotics when not needed (e.g., for viral infections like colds).
Misuse: Not completing prescribed courses, using leftover medicines, or self-medicating.
Agricultural use: Widespread use in livestock and crops accelerates resistance.
Poor infection control: Lack of sanitation, hygiene, and vaccination increases spread.

🦠 Deadliest Resistant Bacteria

Known as superbugs, these cause the most deaths globally:

Escherichia coli
Staphylococcus aureus (including MRSA)
Klebsiella pneumoniae
Streptococcus pneumoniae
Acinetobacter baumannii
Pseudomonas aeruginosa

📊 Global Impact

Deaths: 1.27 million directly caused by bacterial AMR in 2019; 4.95 million associated deaths.
Economy: Could cost $1–3.4 trillion GDP losses annually by 2030.
Healthcare: Longer hospital stays, higher costs, and riskier surgeries (like organ transplants or cancer chemotherapy).

🛡️ How to Combat Resistance

Proper antibiotic use: Only take antibiotics when prescribed.
Complete treatment courses: Prevents survival of resistant bacteria.
Vaccination: Reduces infections that might otherwise require antibiotics.
Hygiene & sanitation: Handwashing, clean water, infection control in hospitals.
Global surveillance: Monitoring resistance patterns to guide treatment.
Research & innovation: Development of new drugs, diagnostics, and non-antibiotic therapies.

📌 Key Takeaway

Antibiotic resistance is not just a medical issue but a global health and economic crisis. Without urgent action, routine infections and surgeries could become life-threatening again.

Probiotics are recommended after antibiotics because antibiotics, while killing harmful bacteria, also disrupt the balance of beneficial gut microbes. Probiotics help restore this balance, reduce side effects, and support overall digestive and immune health.

🔬 Why Probiotics After Antibiotics?

Gut microbiome disruption: Antibiotics wipe out both harmful and beneficial bacteria, leading to imbalance.
Digestive side effects: Diarrhea, bloating, and indigestion are common after antibiotic use.
Probiotic restoration: Probiotics replenish beneficial bacteria, helping digestion and nutrient absorption.
Immune support: A healthy gut microbiome strengthens immunity, reducing risk of secondary infections.

✅ Benefits of Taking Probiotics

Reduced antibiotic-associated diarrhea (especially with Lactobacillus and Saccharomyces boulardii).
Lower risk of yeast infections in women.
Improved gut health and faster recovery of normal flora.
Better tolerance of future antibiotics.

🧪 Common Probiotics Used

Probiotic strain	Benefit
Lactobacillus	Restores gut flora, reduces diarrhea
Bifidobacterium	Improves digestion, boosts immunity
Saccharomyces boulardii	Prevents antibiotic-associated diarrhea and C. difficile infection

📍 Context in India (Mylapore, TN)

Doctors often prescribe probiotic capsules or sachets (like Sporlac, VSL#3, or Saccharomyces boulardii) alongside antibiotics.
Curd (yogurt) and buttermilk are natural probiotic-rich foods commonly recommended here.
Pharmacies stock probiotics as OTC supplements, but dosage should follow medical advice.

⚠️ Precautions

Take probiotics a few hours apart from antibiotics to avoid the antibiotic killing the probiotic bacteria.
Not all probiotics are equal — strain and dose matter.
Immunocompromised patients should consult a doctor before using probiotics.

Would you like me to highlight the best probiotic foods versus supplement options so you can see which is more effective after a course of antibiotics?

Common antibiotics often cause predictable side effects such as digestive upset, headaches, or yeast infections, while some can trigger more specific issues like photosensitivity or severe diarrhea. In India (including Mylapore, TN), doctors frequently prescribe amoxicillin, azithromycin, and ciprofloxacin, each with distinct side effect profiles.

📋 Common Antibiotics and Their Side Effects

Antibiotic	Typical Uses	Common Side Effects	Serious Risks
Amoxicillin	Ear, sinus, lung, urinary infections	Nausea, diarrhea, rash	Rare: severe allergic reaction (anaphylaxis)
Azithromycin	Respiratory infections, STIs, skin infections	Diarrhea, abdominal pain, headache	Rare: heart rhythm disturbances (QT prolongation)
Ciprofloxacin	UTIs, gastrointestinal infections	Nausea, dizziness, insomnia	Tendon rupture, nerve damage, photosensitivity
Tetracyclines (e.g., doxycycline)	Acne, respiratory infections	Stomach upset, photosensitivity	Tooth discoloration in children, liver toxicity
Cephalosporins (e.g., cephalexin)	Skin, urinary, respiratory infections	Diarrhea, headache	Cross-reactivity with penicillin allergy
Sulfa drugs	UTIs, bronchitis	Rash, nausea	Severe allergic reactions, Stevens–Johnson syndrome
Vancomycin	Severe infections, MRSA	Red man syndrome (flushing), nausea	Kidney damage, hearing loss

⚠️ Key Risks & Precautions

Digestive issues (diarrhea, nausea) are the most common across all antibiotics.
Photosensitivity is especially linked to tetracyclines and fluoroquinolones — avoid direct sunlight.
Allergic reactions are most frequent with penicillins and sulfa drugs.
Serious complications like Clostridium difficile infection (severe diarrhea) can occur with broad-spectrum antibiotics.

📍 Context in India (Mylapore, TN)

Amoxicillin and azithromycin are widely prescribed for respiratory infections.
Ciprofloxacin is common for UTIs and gastrointestinal infections but is used cautiously due to tendon risks.
Pharmacies often dispense antibiotics without prescription, but self-medication increases risk of resistance and side effects.

✅ Practical Advice

Always complete the full course unless a doctor advises stopping.
Report any rash, swelling, or breathing difficulty immediately — these may signal allergy.
For mild side effects (nausea, headache), supportive care like hydration and rest usually helps.
Avoid alcohol with metronidazole and avoid sun exposure with tetracyclines/fluoroquinolones.

Would you like me to create a quick-reference chart of antibiotic alternatives (e.g., what doctors prescribe if someone is allergic to penicillin)? That could help distinguish safe options in case of allergies.

Great question — people often confuse antibiotic side effects with allergic reactions, but they’re very different.

⚖️ Side Effects vs Allergic Reactions

Aspect	Side Effects	Allergic Reactions
Cause	Direct pharmacological action of the drug (e.g., irritation, imbalance of gut bacteria)	Immune system overreacts to the drug, treating it as harmful
Onset	Usually predictable, occurs during or after treatment	Can be immediate (minutes–hours) or delayed (days)
Common Symptoms	Nausea, diarrhea, stomach upset, yeast infections	Rash, hives, itching, swelling, breathing difficulty
Severity	Often mild and self-limiting	Can be mild or life-threatening (anaphylaxis)
Management	Adjust dose, supportive care, probiotics	Stop drug immediately, antihistamines, corticosteroids, epinephrine if severe
Examples	Diarrhea with amoxicillin, photosensitivity with tetracyclines	Penicillin allergy causing hives or anaphylaxis

🧪 Key Takeaways

Side effects are expected, dose-related, and not immune-mediated.
Allergic reactions are unpredictable, immune-mediated, and can be dangerous.
Reporting an allergy is critical because future exposure can trigger severe reactions.

📍 Context in India (Mylapore, TN)

Many patients report “penicillin allergy,” but studies show most are actually side effects (like stomach upset), not true allergies.
Hospitals often recommend allergy testing to confirm before ruling out entire antibiotic classes.
Alternatives like macrolides (azithromycin) or fluoroquinolones are used if a true allergy is confirmed.

Would you like me to break down examples of common antibiotics with their typical side effects versus allergic reactions, so you can see how doctors distinguish between the two in practice?