Interactions Cytochrome P450

Question 1

Amiodarone

Answer 1

Inhibit CYP2C9 and CYP 3A4

Can increase bleeding risk on warfarin which is metabolised via CYP2C9

Question 2

Carbamazepine, phenytoin

Answer 2

Induce CYP 3A4

Can cause reduction in ethinyl oestradiol containing contraceptives

Question 3

Warfarin

Answer 3

metabolised by CYP 2C9

Question 4

Clarithromycin, erythromycon

Answer 4

CYP 3A4 inhibitor

can inhibit metabolism of simvastatin and verapamil (metabolised by CYP3A4)

Question 5

diltiazem and verapamil

Answer 5

Inhibit CYP 3A4

This can increase pred levels

Question 6

Fluoxetine, paroxetine

Answer 6

Inhibit CYP2D6

this can increase risperidone levels and risk of extrapyramidal effects and reduce tramadol effects due to low levels of active metabolite

Question 7

metronidazole

Answer 7

CYP2C9 inhibitor

can interact with warfarin, increase risk of bleeding