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? 

Phenytoin, phenobarbitone and carbamazepine decrease the Pill’s effectivity and therefore the chance of unplanned pregnancy is greater.

Drugs that work with the pill:

• Valproate 
• Lamotrigine

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

Oral contraceptives decreases Lamotrigine and Valproate’s plasma levels, and therefore these drugs dosages would have to be increased to keep them from becoming sub-therapeutic while taking the pill. 

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

• Neonates have slower metabolism because they have reduced hepatic activity and therefore the drugs will stay in their systems for longer.
• Babies and children have faster metabolism than in adults and they might require a higher dose than an adult.
• Geriatrics need to be given lower dosages due to their lowered metabolic activity. 

In which cases is plasma blood level monitoring indicated?

• Valproate decreases the metabolism of Lamotrigine, and this can lead to toxicity. Therefore, blood levels should be monitored.