FACTORS AFFECTING BIOTRANSFORMATION OF DRUGS

Sponsored Links

Biotransformation of drugs is defined as the chemical conversion of one form of the drug to another form. In general sense biotransformation is often referred to as metabolism.{1} Based on the rate of metabolism of the drug several properties of the drug like its biological half life, its therapeutic efficacy and toxicity are determined. Therefore it is worth to get through the factors affecting the biotransformation of drug. There are several factors as follows: 1. Physicochemical properties of the drug: As we are well aware of the affect of physicochemical properties of the drug on absorption and distribution of the drug even the metabolism is affected the same way. For the biotransformation of drug to occur it requires interaction with the enzyme, i.e an interaction where special arrangement is critical. Some other properties like molecular size and shape, pKa of a drug influence its interaction with the active sites of enzymes and there by the biotransformation process to which it is subjected.{1} 2. Chemical factors: They include induction and inhibition of drug metabolizing enzymes and certain environmental chemicals. Induction of drug metabolizing enzymes: "The phenomenon of increased drug metabolizing ability of the enzymes by several drugs and chemicals is called as enzyme induction and the agents which bring about such an effect are known as enzyme inducers." Chemically there are two categories of enzyme inducers namely: Phenobarbital type inducers and polycyclic hydrocarbon type inducers. Inhibition of drug metabolizing enzymes: A decrease in the drug metabolizing capacity of an enzyme is called as enzyme inhibition. The process of inhibition may be direct or indirect. Direct inhibition can occur by three mechanisms as follows: (a)Competitive inhibition. (b)Non-Competitive inhibition (c)Product inhibition. Indirect inhibition may be by: (a)Repression (b)Altered physiology 3.Biological factors: Several biological factors like species differences, strain differences, sex differences, age, diet and altered physiological factors like pregnancy, hormonal imbalance, disease states and temporal factors like circadian rhythms etc.{1} Therefore all the above factors affecting bioavailability of drugs should be taken into consideration for obtaining expected therapeutic response with minimal side effects. References: Biopharmaceutics and Pharmacokinetics a Treatise by D.M.Brahmankar and Sunil B.Jaiswal Vallabh Prakashan [Reprint in 2010] {1}Page no:180 - 189 "This blog do not contain any plagiarized material"

About the Author

Comments

KRISHNA's picture

PRAVEEN WHAT A WORK DONE BY U MAN REALLY MIND BLOWING DEAR.....

KRISH

Siriki Praveen Kumar's picture

thankyou....

Regards,

S. Praveen Kumar.

sirikipraveen11@gmail.com

Pharma warriors

You May Also Like..