Cytochrome P450 enzymes are essential to metabolise many medications.
Cytochrome P450 (CYP450) enzymes can be inhibited or induced by some drugs, resulting in significant drug interactions that can cause unanticipated adverse reactions or therapeutic failures.
An easy way to remember the mnemonic is; CRAP GPs spend all day on SICKFACES.com.
Cytochrome P450 Inducers
CYP450 inducers reduce the concentration of drugs metabolised by the CYP450 system.
The mnemonic CRAP GPs can be used to easily remember common CYP450 inducers.
- Carbemazepines
- Rifampicin
- Alcohol
- Phenytoin
- Griseofulvin
- Phenobarbitone
- Sulphonylureas
Cytochrome P450 Inhibitors
CYP450 inhibitors increase the concentration of drugs metabolised by the CYP450 system.
The mnemonic SICKFACES.COM can be used to easily remember common CYP450 inhibitors.
- Sodium valproate
- Isoniazid
- Cimetidine
- Ketoconazole
- Fluconazole
- Alcohol & Grapefruit juice
- Chloramphenicol
- Erythromycin
- Sulfonamides
- Ciprofloxacin
- Omeprazole
- Metronidazole
Common Interactions
Exampled of drugs that commonly interact with CYP450 enzyme inhibitors and inducers are; Warfarin the Combined Contraceptive Pill, Theophylline, Corticosteroids, Tricyclics, Pethidine, and Statins.
