Anti-epileptics

Question 1

Which anti-epileptics increase oral contraceptive metabolism?

Answer 1

Cytochrome P450 inducers; carbamazepine, phenytoin, phenobarbitol, these patients should not have oral contraceptive, they should be advised barrier method or IUD

Question 2

What is the risk of taking lamotrigine with combined oral contraceptive pill?

Answer 2

lamotrigine does not impact liver enzymes so it does not effect COC pharmokinetics but oestrogen in the COC reduces lamotrigine levels and increases risk of seizure - progesterone only contraceptives are preferred

Question 3

What contraceptive would you recommend with lamotrigine?

Answer 3

progesterone only (oestrogen reduces lamotrogine levels and increases risk of seizure) - depo, pop, implant, mirena or copper IUD

Question 4

What is the risk of taking sodium valproate with combined oral contraceptive pill?

Answer 4

sodium valproate does not impact liver enzymes so it does not effect COC pharmokinetics but oestrogen in the COC reduces sodium valproate levels and increases risk of seizure - progesterone only contraceptives are preferred

Question 5

Which anti-epileptic is considered to have the safest profile in pregnancy?

Answer 5

carbamazepine

Question 6

Which anti-epileptic is considered to be the most teratogenic?

Answer 6

sodium valproate