Safe Anti-Epileptics - Not Enzyme Inducers or Inhibitors - Dr. Adil Ramzan

Sometimes it becomes difficult to choose a drug in those patients who have multiple co-morbidities. That is are suffering from more than one disease and physician needs to choose a few out of many drugs to avoid drug-drug interactions.

Anti-epileptic drugs, or the drugs which are used to treat seizures, do interact with other drugs. 

Carbamazepine, phenytoin, phenobarbital, oxcarbazepine, topiramate and primidone are enzyme inducers. Enzyme inducers decrease the efficacy of a drug which is metabolized by the induced enzymes because more concentration of the enzyme will be available and the drug will be quickly metabolized and removed from the system. 

Valproic acid, felbamate, rufinamide, and stiripentol, on the other hand, are enzyme inhibitors. 

Therefore, we can't give these drugs to a patient who is taking a drug for any medical problem which is metabolized by the liver enzymes (eg cytochrome p450 enzyme system). 

The anti-epileptic drugs which are not an enzyme inducer or inhibitor. 

The following three anti-epileptic drugs are neither enzyme inducers, nor inhibitors and can be used safely in those patients who are taking drugs which are metabolized by liver enzyme system. 

1. Levetiracetam. 

2. Vigabatrin

3. Gabapentin

4. Lamotrigine

Levetiracetam and gabapentin are widely used drugs for this purpose. Vigabatrin is not available in most of the countries as of now (8/27/2017). Lacosamide another anti-epileptic is also found to be safe. 

Special Thanks: 

Professor Dr. Rauf Niazi, Dean, Dept. of Medicine SZABMU, PIMS, Islamabad.(for providing this information to us, his students). 

Dr. Fibah Syed, Asst. Professor, SZABMU, PIMS

Dr. Shaukat Bukhari. Registrar Medicine, SZABMU PIMS. 

Author:

Dr. Adil Ramzan.

MBBS, MD Internal Medicine Resident. 

SZABMU, Pakistan Institute of Medical Sciences. Islamabad. Pakistan.