Enzyme induction: Increase in enzyme activity is called enzyme induction.
- Clinically important drug-drug interactions may result in for example:
- failur of oral contrceptives.
- Loss of anti-coagulant control
- failure of cytotoxic chemotherapy.
- Tolerance to drug therapy.eg.anti-epilepsy drug.
- Variability in response to drugs is increased.Enzyme induction caused by heavy alcohol drinking or heavy smoking may be an unrecognized cause for failure of an indivudal to achieve the exected response-warferin,theophylline.
- Drug toxicity may occur.A patient who becomes enzyme induced by taking rifampicin is more to develop liver toxicity after paracetamol overdose by increased production of a hepatotoxic metabolite. (Ref:Bennett-10th,P-98)