Hepatic enzyme inducers and Hepatic enzyme inhibitors

Hepatic enzyme inducers

• Decrease the bioavailability of other drugs that are metabolised by those enzymes
• Increase the bioavailability of other drugs that require metabolism for their activation
• Examples include:
• Long term alcohol abuse
• Rifampicin
• Anticonvulsants: phenytoin, carbamazepine, phenobarbitone, primidone
• Spironolactone
• Griseofulvin

Hepatic enzyme inhibitors

• Increase the bioavailability of other drugs that are metabolised by those enzymes
• Decrease the bioavailability of other drugs that require metabolism for their activation
• Examples include:
• Alcohol consumed during 'binges'
• Antibiotics
• Isoniazid
• Erythromycin
• Sulphonamides
• Metronidazole
• Chloramphenicol
• Ketoconazole
• Anticonvulsants
• Valproate
• Cimetidine
• Allopurinol
• Chlorpromazine
• Imipramine
• Propranolol
• Metoprolol
• Interferon