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?  

• Phenobarbital 

• Topiramate 

• Phenytoin 

• Carbamazepine 

• Oxcarbazepine  

These drugs reduce the effectivity of oral contraceptives 

Drugs that are safe to use in combination with the Pill is: 

• Valproate  

• Lamotrigine  

• Gabapentin  

• Levetiracetam  

• Vigabatrin 

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

Yes. Oral contraceptives reduce the plasma concentration of valproate and lamotrigine.  

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

In neonates the metabolism of these drugs is slow 

In children, these drugs are metabolized faster than in adults 

Elder people should be given a lower dosage as their renal function is lower 

In which cases is plasma blood level monitoring indicated? 

• During pregnancy 

• When breakthrough seizures occur 

• To guide dose adjustment 

• When an interacting medication is added or removed from the patient's regime  

•  To assess adherence 

• To determine whether adverse effects are related to drug levels. 

In geriatric it's important to monitor blood levels as their renal function is low thus drug clearing will be slowed down, meaning high levels of the drug remains in the patient's blood stream.  

Patient with kidney and liver diseases should also be monitored.