Category: 01. General Pharmacology

Excretion of drugs means the transportation of unaltered or altered form of drug out of the body. The major processes of excretion include renal excretion, hepatobiliary excretion and pulmonary excretion. The minor routes of excretion are saliva, sweat, tears, breast milk, vaginal fluid, nails and hair.The rate of excretion influences the duration of action of…

Drugs are chemical substances, which interact with living organisms and produce some pharmacological effects and then, they should be eliminated from the body unchanged or by changing to some easily excretable molecules. The process by which the body brings about changes in drug molecule is referred as drug metabolism or biotransformation. Enzymes responsible for metabolism…

The exact relationship between the dose and the response depends on the biological object under observation and the drug employed.When a logarithm of dose as abscissa and responses as ordinate are constructed graphically, the “S” shaped or sigmoid type curve is obtained.The lowest concentration of a drug that elicits a response is minimal dose, and…

A drug may act:(i) Extracellularly e.g: osmotic diuretics, plasma expanders.(ii) On the cell surface e.g.: digitalis, penicillin, catecholamines(iii) Inside the cell e.g.: anti-cancer drugs, steroid hormones.

Most of the drugs act by interacting with a cellular component called receptor. Some drugs act through simple physical or chemicalreactions without interacting with any receptor.• Receptors are protein molecules present either on the cell surface or with in the cell e.g. adrenergic receptors, cholinoceptors, insulin receptors, etc.• The endogenous neurotransmitters, hormones, autacoids and most…

Minerals: Liquid paraffin, magnesium sulfate, magnesium trisilicate, kaolin, etc. Animals: Insulin, thyroid extract, heparin and antitoxin sera, etc. Plants: Morphine, digoxin, atropine, castor oil, etc. Synthetic source: Aspirin, sulphonamides, paracetamol, zidovudine, etc. Micro organisms: Penicillin, streptomycin and many other antibiotics. Genetic engineering: Human insulin, human growth hormone etc.Out of all the above sources, majority of…