NOMENCLATURE AND CLASSIFICATION OF DRUGS

NOMENCLATURE OF DRUGS

The term drug nomenclature implies that there are several names that can be used to identify a drug

Drugs have three different names;

1. Chemical Name 2. Non Proprietary name 3. Proprietary name.

CHEMICAL NAME

A chemical name is given when a new chemical entity (NCE) is developed.

It is the name given to drug in accordance with rules of chemical nomenclature established by International Union of Pure and Applied Chemistry.

It is useful for chemists or technical personnel as it provides the precise arrangement of atoms and atomic groups in the molecule.

It is not used to identify the drug in a clinical or marketing situation.

NON PROPRIETARY NAME

It is a short name given to a drug that is not subject to proprietary rights. The nonproprietary name should always be concise and meaningful. This is used in discussion and textbooks.

There are two classes of non proprietary names; 1. Approved Name 2. Official Names APPROVED NAME: This name is given to drug by bodies

like United Stats Adopted Name Council (USAN) and British Approved Name (BAN) soon after its introduction.

This name sometime referred to as generic name however this term is used to designate a chemical or pharmacological class of drugs such as Sulphonamide, Penicillin.

OFFICIAL NAMES: It is the name approved by the National Pharmacopeia Commission and included in the official book i.e. Pharmacopeia.

The official name must be identical with approved name.

PROPRIETARY NAME It is the name given to a drug by the pharmaceutical firm which sell

the drug.

Thus a single drug is sold under many proprietary names by different firms.

They are written with capital initial letter and are often further distinguished by superscript R in circle ®

Clinicians usually described drug by their proprietary names.

EXAMPLE

ParacetamolCHEMICAL NAME: N-(4-hydroxyphenyl)acetamide.

NON-PROPRIETARY NAME: Approved Name: British Approved Name (BAN):

paracetamol United States Adopted Name (USAN):

acetaminophen

Official Name: Acetaminophen

PROPRIETARY NAME: Panadol, Calpol, Adol

CLASSIFICATION OF DRUGS

It is essential because it allows several thousand of drugs to be reduced to a manageable number of group.

There is no uniform or homogenous system of classifying drugs that suits all purposes.

Drugs are classified according to the convenience of the person discussing them. Chemist, Pharmacologist , Pharmacist and Clinician

We classify the drugs based on

CLASSIFICATION OF DRUGS

1. Chemical Nature

2. Source

3. Target organ/Site of Action

4. Mode of Action

5. Therapeutic Uses

6. Physiological system

7. Physical Effects

1. CLASSIFICATION BASED ON CHEMICAL NATURE

Chemical Nature of drug is discussed by a Chemist and based on chemical nature we divide drugs into

INORGANIC DRUGS Metals and their Salts (Ferrous Sulphate, Zinc

Sulphate, Magnesium Sulphate. Non Metals Includes Sulphur.ORGANIC DRUGSAlkaloids (atropine, Morphine, Strychnine) Glycosides (Digitoxin, Digoxin).Proteins(Insuline, Oxytocin)Esters, Amide, Alcohol, Glycerides.

2. CLASSIFICATION BASED ON SOURCE

Natural SourcePlants (Morphine,

Atropine, Digitoxin)Animals (Insuline, eCG)Micro organism

(Penicillin)Mineral (Sodium

Chloride)

Synthetic Source(Sulphonamide, Procaine).

Semi-synthetic Source

Amoxicillin, Ampicillin, Doxycycline

Bios-ynthetic Source

Recombinant Human erythropiotin, Recombinant bovine somattotropine

Sources of drugs are discussed by a Pharmacologist and Pharmacist

3. CLASSIFICATION BASED ON TARGET ORGAN

Drugs acting on CNS (Diazepam, Phenobarbitone).

Drugs acting on Respiratory System (Bromhexaine).

Drugs acting on CVS (Digitoxin, Digoxin).

Drugs acting on GIT (Omeprazole, Kaoline, Sulphadimidine).

Drugs acting on Urinary System (Magnesium Sulphate, Lasix

Drugs acting on reproductive system (Oxytocin, Estrogen)

Classification based on target organs are done by the Physicians.

4. CLASSIFICATION BASED ON MODE OF ACTION

Inhibitor of bacterial cell wall synthesis (penicillin)Inhibitor of bacterial protein synthesis

(Tetracycline)Calcium Channel blocker (Verapamil, nifedipine)

5. CLASSIFICATION BASED ON THERAPEUTIC USE

Classification based on mode of action is done by Physicians & Pharmacologists.

Antimicrobials/Antibacterials (Penicillin, Streptomycin, Quinolones, Macrolides).

Antihypertensive (Clonidine, hydralazine, Enalpril).

Classification based on mode of action is done by Physicians & Pharmacologists.

Antidiarrheals (Lopramide, Kaoline).Antiemetics (Domperidone, Meclizine and

Metoclopramide).

6. CLASSIFICATION BASED ON PHYSIOLOGICAL SYSTEM

Sympathomimetics (Adrenaline, Noradrenaline).Parasympathomimetics (Carbachol, Pilocarpine,

Neostigmine).Neuromuscular blockers Suxamethonium, Gallamine).

7. CLASSIFICATION BASED ON PHYSICAL EFFECTS

Emollients (Lanolin, Vaseline)Caustics (Silver nitrate)Demulcents (Zinc Oxide, Tannic Acid).