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CLASSIFICATION OF DRUGS

REGULATION OF MEDICINES

NAMING OF DRUGS.

E. A. OGBOLE

BINGHAM UNIVERSITY,JOS CAMPUS

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Definition.

A very broad definition of a drug would include all chemicals other than food that affect living processes.

Chemotherapeutic agents – used to cure infectious diseases and cancer.(antibiotics ,etc)

If the effect helps the body, the drug is a medicine, if a drug causes harmful effects on the body, the drug is a poison.

A drug can also be defined as medicinal agents used for diagnoses,prevention,treatment of symptoms and cure of diseases.

Contraceptives would be outside of this definition unless pregnancy were considered a disease.

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Drug classification.

Drugs can be classified according to various criteria :

Chemical structure

pharmacological action.

Pharmacodynamic agents – used in non-infectious diseases(cholinergic, adrenergic, hallucinogenic, )

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Sites of drug action.
Enzyme inhibition.
Drugs act within the cell by modifying normal biochemical reactions.
Enzyme inhibition may be reversible or non reversible, competitive or non-competitive.
Drug-receptor interaction
Drugs act on the cell membrane by physical and/or chemical interactions.
This is usually through specific drug receptor sites known to be located on the membrane.
A receptor is the specific chemical constituents of the cell with which a drug interacts to produce its pharmacological effects.

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Non-specific interactions.

Drugs act exclusively by physical means outside of cells.
These sites include external surfaces of the skin and gastrointestinal tract.

Drugs also act outside of cell membranes by chemical interactions.

Neutralization of stomach acid by antacids is a good example.

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CHEMICAL STRUCTURE

Nitroimidazole
Metronidazole, Secnidazole, Tinidazole, Ornidazole.

4 – aminoquinolines
Chloroquine, amodiaquine, Quinine,Piperaquine(bisquinoline),Mefloquine

8 – aminoquinolines
Primaquine,

Quinolones
Nalidixic acid, Ciprofloxacin, Ofloxacin, Levofloxacin

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Sesquiterpenes
Artemether, Artesunate, Arteether, Dihydroartemisinin

Sulphonamides
Cotrimoxazole, Pyrimethamine, Glucophage

Penicillines
Ampicillin, Cloxacillin, Cephalexin, Ceftriaxone, Ceftazidime, Cefotaxime

Amino glycosides
Gentamycin, Kanamycin, Streptomycin, Neomycin.

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Macrolides
Erythromycine, Clarithromycin, Azithromycine.

Salicylates
Aspirin, Mefenamic acid, Ibuprofen, Piroxicam

Opiates
Pentazocine, Morphine, Codeine, Pethidine

Benzodiazepine
Lorazepam, Diazepam, Midazolam, Nitazepam, Bromazepam.

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Pharmacological action

Alimentary system

Antacids
Sodium Bicarbonate, Magnesium hydroxide, Aluminium hydroxide.
H_{2 -} inhibitors - Cimetidine, Ranitidine, Nizatidine, Famotidine
PPIs - Omeprazole, Lanzoprazole, Rabiprazole

Gastro intestinal sedatives
Hyoscine, Atropine, Scopolamine, Domperidone

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Laxatives and Purgatives
Bisacodyl, Docusates,Lactulose,Senna

Anthelmintics
Albendazole, Mebendazole, Levamisole, Bephenium hydroxynaphthoate, Pyrantel pamoate

Antidiarrhoeals
Hyoscine, Loperamide, Diphenoxylate HCL,

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Drugs acting on the cardiovascular system

Cardiac reactants
Digoxin, Propranolol, Amiodarone, Atenolol

Reactants on vascular system
Antihypertensives
Calcium channel blockers
Nifedipine, Amlodipine,Felodipine, Diltiazem, Verapamil

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B – Blockers
Propranolol, Atenolol, Labetalol,Timolol
Vasodilators
Methyldopa, Hydrallazine
Anticoagulants
Warfarin, Heparin
Antiplatelet
Aspirin, Clopidogrel

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Drugs affecting the CNS
Analgesics/Antipyretics
Paracetamol, Aspirin, Dipyrone(metamizol).

NSAIDS
Ibuprofen, Piroxicam, Tramadol, Diclofenac

Opiate analgesics
Pentazocine, Morphine,Pethilophan,Petidine

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Hypnotics
Phenobarbitone, Flunitrazepam
Sedatives/Tranquilizers( anxiolytics)
Diazepam, Nitrazepam, Triazolam, Bromazepam
Antipsychotics
Thioridazine, Chlorpromazine, Fluphenazine

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Anticonvulsants
Phenytoin sodium, Sodium valproate, Clonazepam.
Muscle relaxants
Methocarbamol, Orphenadrine, Suxamethonium
Antihistamines
Chlorpheniramine, Prometazine, Loratadine,Mepyramine, Astemizole,Diphenhydramine,

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Antidepressants
Imipramine, Amitriptyline, Clomipramine
Corticosteroids
Prednisolone, Dexamethasone, Betamethasone.
Antibiotics
Ampicillin, Amoxycillin,Doxycycline, Erythromycin.

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DIURETICS
Frusemide, Amiloride,Hydrochlorothiazide, Spironolactone.
Antivirals
Acyclovir, Lamivudine, Ganciclovir
Antiretrovirals
Zidovudine, Nevirapine, Stavudine etc.

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The Anatomical Therapeutic Chemical Classification System.

ATC/DDD.

Definition

The ATC/DDD system classifies therapeutic drugs.

Purpose

The purpose of the ATC system is to serve as a tool for drug utilization research in order to improve quality of drug use.

Classification Structure .

In the ATC classification system, the drugs are divided into different groups according to –

The organ or system on which they act

Their chemical, pharmacological and therapeutic properties.

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19.

In this system, drugs are classified into groups at different levels.

First level.

This first level of the code indicates the anatomical main group and consists of one letter. These are 14 main groups.

code
A	Alimentary tract $ metabolism
B	Blood $blood forming organs
C	Cardiovascular system
D	dermatologicals
G	genito-urinary sys. $ sex hormones
H	Systemic hormonal preps excluding sex hormones $insulin
J	Anti-infectives for systemic use.
L	Antineoplastic $ immunomodulatory agent.
M	Musculo-skeletal system
N	Nervous system
P	Antiparasitic pdts,insecticides $ repellents.
R	Respiratory system
S	Sensory organ
V	Various.

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20.

Second level.

The second level of the code indicates the therapeutic main group and consists of two digits.
Example : CO3 diuretics.

Third level

The third level of the code indicates the therapeutic/pharmacological subgroup and consists of one letter.
Example : CO3C high ceiling diuretics.

Fourth level

The fourth level of the code indicates the chemical/therapeutic/pharmacological subgroup and consists of one letter.

Example : CO3CA sulphonamides.

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21.

Fifth level.

The fifth level of the code indicates the chemical substance and consists of two digits.
Example : CO3CA01 furosemide.

The DDD.

Defined Daily Dose is the assumed average maintenance dose per day for a drug used for its main indication in adults.

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22.

Drug names.

Chemical names.

The chemical name is assigned according to rules of nomenclature of chemical compounds.

Brand or trade name.

The brand name is always capitalized and is selected by the manufacturer.

The generic name.

The generic name refers to a common established name irrespective of its manufacturer.

In most cases a drug bearing a generic name is equivalent to the same drug with a brand name.

This equivalency is not always true.

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23.

Drugs are chemically equivalent, different manufacturing processes may cause difference in pharmacological actions.

Several differences may be crystal size or form,isomers,crystal hydration, purity(type and number of impurities), vehicles,binders,coatings,dissolution rate and storage stability.

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REGULATION OF MEDICINES. 24.

NAFDAC.

The National Agency for Food and Drug Administration and Control was established as a parastatal of the Federal Ministry of Health by decree No. 15 of 1993.

It has the mandate to regulate medicine products intended for use in the diagnosis, cure, mitigation, treatment or prevention of diseases.

Operators of all indigenous and non-indigenous drug establishments that engage in the manufacture , preparation, propagation, compounding or processing of drugs are required to register and submit a list of every drug in commercial distribution.