GC

1.-NOMENCLATURE-AND-CLASSIFICATION-OF-DRUGS

NOMENCLATURE AND CLASSIFICATION OF DRUGS

NOMENCLATURE OF DRUGS

  • The term drug nomenclature refers to the various names that can identify a drug.

  • Drugs are known by three different names:

    1. Chemical Name

    2. Non-Proprietary Name

    3. Proprietary Name

CHEMICAL NAME

  • Given when a New Chemical Entity (NCE) is developed.

  • Complies with the rules established by the International Union of Pure and Applied Chemistry.

  • Useful for chemists, detailing the precise arrangement of atoms and groups within the molecule.

  • Not generally used in clinical or marketing contexts.

NON PROPRIETARY NAME

  • A concise name assigned to a drug not subject to proprietary rights.

  • Commonly used in discussions and textbooks.

  • Two classes of non-proprietary names:

    1. Approved Name

    2. Official Name

Approved Name

  • Assigned by organizations like the United States Adopted Name Council (USAN) and British Approved Name (BAN) post-introduction.

  • Often referred to as Generic Name, though this can refer to a class of drugs (e.g., Sulphonamide, Penicillin).

Official Name

  • The name approved by the National Pharmacopeia Commission, as included in the Pharmacopeia.

  • Must be identical to the approved name.

PROPRIETARY NAME

  • Assigned by the pharmaceutical company marketing the drug.

  • Each drug can have multiple proprietary names from different manufacturers.

  • Written with an initial capital letter and often accompanied by a superscript ®.

  • Clinicians typically refer to drugs by their proprietary names.

EXAMPLE: Paracetamol

  • CHEMICAL NAME: N-(4-hydroxyphenyl)acetamide.

  • NON-PROPRIETARY NAME:

    • Approved Name (BAN): paracetamol

    • USAN: acetaminophen

    • Official Name: Acetaminophen

  • PROPRIETARY NAME: Panadol, Calpol, Tempra, Biogesic

CLASSIFICATION OF DRUGS

  • Classification is crucial for reducing thousands of drugs to manageable groups.

  • No uniform classification system exists, as it varies based on context (chemist, pharmacologist, pharmacist, clinician).

Classification Methods

  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

  • Inorganic Drugs:

    • Metals and their Salts: (e.g., Ferrous Sulphate, Zinc Sulphate, Magnesium Sulphate)

    • Non-Metals: (e.g., Sulphur)

  • Organic Drugs:

    • Alkaloids: (e.g., atropine, morphine, strychnine)

    • Glycosides: (e.g., digitoxin, digoxin)

    • Proteins: (e.g., insulin, oxytocin)

    • Esters, Amides, Alcohols, Glycerides.

2. Classification Based On Source

  • Natural Source:

    • Plants:

      • Morphine: derived from opium poppy

      • Atropine: synthesized from Atropa belladonna

      • Digoxin: extracted from woolly foxglove leaves

    • Animals:

      • Insulin: originally from cows and pigs’ pancreas

    • Microorganisms:

      • Penicillin: derived from Penicillium mold

    • Minerals:

      • Sodium Chloride: pharmaceutical-grade salt

  • Synthetic Source:

    • Sulphonamide: man-made antibacterial drugs

    • Procaine: local anesthetic

  • Semi-Synthetic Source:

    • Amoxicillin: enhanced penicillin antibiotic

    • Ampicillin: broad-spectrum penicillin

    • Doxycycline: semi-synthetic tetracycline derived from Streptomyces

  • Bio-Synthetic Source:

    • Recombinant Human Erythropoietin: biopharmaceutical for anemia treatment

    • Recombinant Bovine Somatotropin: from genetically modified E. coli

3. Classification Based On Target Organ/Site

  • CNS Drugs: Diazepam, Phenobarbitone

  • Respiratory Drugs: Bromhexaine

  • CVS Drugs: Digitoxin, Digoxin

  • GIT Drugs: Omeprazole, Kaoline, Sulphadimidine

  • Urinary System Drugs: Magnesium Sulphate, Lasix

  • Reproductive Drugs: Oxytocin, Estrogen

4. Classification Based On Mode Of Action

  • Bacterial Cell Wall Synthesis Inhibitors: Penicillin

  • Bacterial Protein Synthesis Inhibitors: Tetracycline

  • Calcium Channel Blockers: Verapamil, Nifedipine

5. Classification Based On Therapeutic Use

  • Antimicrobials/Antibacterials: Penicillin, Streptomycin, Quinolones, Macrolides

  • Antihypertensives: Amlodipine, Hydralazine, Enalapril

  • Antidiarrheals: Loperamide

  • Antiemetics: Domperidone, Meclizine, 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: Soothing agents (e.g., Lanolin, Vaseline)

  • Caustics: Things that can destroy by chemical action (e.g., Silver Nitrate)

  • Demulcents: Relieve inflammation (e.g., Zinc Oxide, Tannic Acid)

LEGAL CLASSIFICATION

  • Prescription: Requires an order from licensed health practitioners (e.g., physicians, pharmacists).

  • Non-Prescription: Over-the-counter (OTC) drugs available without a prescription.

ROLE OF RADIOLOGIC TECHNOLOGISTS

  • Broad knowledge of drugs (classification, actions, interactions, reactions) is expected for RTs.

  • Skills in drug administration help in various clinical scenarios.

Drug knowledge is key to enhancing patient care and maintaining professional competency.