Saturday, July 24, 2010

What is drug interaction

What is drug interaction?: Drug interaction can be defined as interference in pharmacological activity of a drug by other drug or a constituent of food so that the desired actions of a drug is hindered or reduced or potentiated, due to various phenomenons like induction of inhibition of enzymes and proteins which are responsible for metabolism of other drug and result in to degradation one or the other administered drug.
Al most every drug is able to affect pharmacological activity of one or the other drug, we are providing in brief some basic mechanisms by which drug interaction occurs.

1. Modifying metabolism of a particular drug
A particular drug can induce enzymes responsible for metabolic degradation of other drug; this is due to induction or enhancement of degradative enzyme system which is already in place like liver or peripheral enzymes.

2. Modifying absorption of a drug
A drug can create an environment which may result in increased or decreased absorption of a particular drug.

3. Modifying distribution of a drug in body :
A drug can induce or enhance enzymes or proteins which binds other drug so that the drug is not free to exert the desired action at particular site.

4. Modifying Metabolism and Biotransformation of a drug:
Particular drug may interfere in biotransformation and metabolism of a drug making it difficult to get elimination or degradation or may result in potentiating of activity or reduction of activity due to improper conversion in to active form.

5. Modifying Elimination of a drug from body
A particular drug may modify elimination by modifying the PH so that the drug is eliminated faster or it is reabsorbed.

6. Potentiating Agonistic and antagonistic actions
A drug can potentiate a particular pharmacological action; by increasing each others activity one or the other drug may potentiate activity of each other and resulting in a synergistic action. which may cause harmful effect.

A drug may potentiate antagonistic action of other drug by virtue of several mechanisms like inhibition enzyme in the critical path way of degradation.
Some drug interactions is intentionally made use for enhancing activity of a particular drug or reducing activity of other drug.

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