CYP450

Question 1

What are CYP450 enzymes?

Answer 1

They are a class of oxidase enzymes which break down drug compounds, xenobiotics, fatty acids etc.

Question 2

Name some CYP450 inducers and what is the implication?

Answer 2

Mnemonic: CRAP GPs induce me to madness

Carbamazepine
Rifampicin
Alcohol (chronic use)
Phenytoin

Griseofulvin/Green vegetables
Phenobarbitones
St John’s Wort

Implication: Need to increase dose of drug i.e warfarin as there is increased breakdown

Question 3

Name some CYP450 inhibitors and what is the implication?

Answer 3

Mnemonic: SICK FACES.COM GROUP

Sodium valproate
Isoniazid
Cimetidine
Ketoconazole

Fluconazole
Alcohol (binge)/Amiodarone
Chloramphenicol
Erythromycin
Sulfonamides

Ciprofloxacin
Omeprazole
Metronidazole
Grapefruit juice

Implication: Need to decrease dose of drug i.e warfarin as there is decreased breakdown

Question 4

Is acute alcohol intake an inducer or inhibitor?

Answer 4

Inhibitor

Question 5

Is chronic alcohol intake an inducer or inhibitor?

Answer 5

Inducer