• Which of the anti-epileptic drugs affect the metabolism of the Pill (oral contraceptive) and what are the implications of this? Which drugs are safe to use in combination with the Pill? 

Anti-epileptic drugs that decrease the effectiveness of oral contraceptives include: phenobarbitone, phenytoin, carbamazepine, oxcarbazepine and topiramate. The implications of this are that the female patient can have an unwanted pregnancy, or the patient’s hormone levels will not be regulated as it should because of the contraceptive not reaching therapeutic effective levels to prevent ovulation. Anti-epileptic drugs that are safe to use with oral contraceptives are valproate, lamotrigine, gabapentin, levetiracetam, vigabatrin.

• Can oral contraceptives also affect the effectivity of the anti-epileptic drugs?

Oral contraceptives can decrease serum levels of anti-epileptic drugs; examples of these drugs are lamotrigine and valproate. Therefore Yes.

• How does age affect the kinetics of these drugs (from neonates to old age)?

Neonates have a slower metabolism and should therefore receive lower dosages. Babies and children have a faster metabolism than adults and should receive higher dosages. For geriatric patient’s lower dosages are required due to slower metabolism and decreased renal function.

• In which cases is plasma blood level monitoring indicated?

Where protein binding takes place and in certain diseases that may affect protein binding, these cases are with chronic kidney failure, liver diseases, hypoalbuminemia, burns, pregnancy, malnutrition, age and where displacement drugs are involved. In these instances, plasma blood level monitoring is required.