Drugs

The word Drug is derived from Drouge (French word)=a dry herb.

Definition(Drug):

Drugs are chemical substance.According to the WHO,1992:

‘A drug is any substance or products that is used or intended to be used to modify or explore the physiological system or pathological states for the benefit of the recepient.’(Ref:Laurence-10,P-5)

Example:Paracetamol,Aspirin etc.

Aims of drug/Purpose of drug/Use of drug:

[A] For the treatment for disease:

1)      Antibiotics for infection.

2)      Analgesics for pain.

3)      Isoniazid for TB.

[B] For control of disease:

1)      Antihyperyensive drugs for hypertension.

2)      Insulin for dibatic mellitus.

[C] For prevention of disease:

1)      BCG for TB.

2)      TT for tetanus.

[D] For diagnosis of disease:   

           

1)      Baso4 for diagnosis of PUD.

2)      Endrophonium for myasthenia gravis.

Properties of ideal drug:

1)      A drug molecule must have appropiate size,shape,electrical charge and atomic composition.

2)      Must have the properties to be transported from site of administration to the site of action(target site).

3)      Should be inactivated or excereted from the body at a reasonable rate so that its action will be of appropriate duration.

Classification of drugs:

1.       Therapeutic use:eg. antimicrobial,anti-diabetic,analgesic.

2.       Mode or site of action:

·         Molecular structure-eg. steriod,alkaloid,glycoside.

·         Molecular interaction-eg.receptor blockers,enzyme inhibitors.

·         Cellular site-eg.Loop diuretic,catecholamine uptake inhibitors.