Clinical Pharmacology of Topiramate versus Lamotrigine versus Phenobarbital: Comparison of Efficacy and Side Effects Using Odds Ratios

Clinical pharmacologists, neurologists, internists, and all health care givers must consider the efficacy, safety, and side effect profile of a given antiepileptic drug (AED) when determining which drug is best for a given patient. The first purpose of this paper is to address whether the “new” AEDs have advantages over the “old” drugs. The second purpose is to teach those interested in clinical pharmacology about the use of Web‐based information access to answer a neurology/clinical pharmacology problem: to compare the efficacy and side effects of topiramate versus lamotrigine versus phenobarbital using odds ratios. Cost of all three AEDs was also compared. A number of new AEDs, including topiramate and lamotrigine, have been developed for chronic focal and secondarily generalized epileptic seizures. Efficacy of these drugs as anticonvulsants does not seem to be superior to that of traditional anticonvulsants such as phenobarbital. However, the advantage of the new drugs is a different spectrum of possible adverse events. Newer AEDs may or may not induce sedation and may minimize noncompliance by reducing side effects of lethargy and cognitive impairment. The difficulty in achieving therapeutic dosage because of side effects makes one consider whether these agents are “better” than the oldest and most side effect—prone AED, phenobarbital. The new AEDs have less frequent interactions, leading to improved tolerability with comedication. This exercise compares two “new” AEDs, topiramate and lamotrigine, with phenobarbital by evaluating efficacies and side effects using relative odds ratios, a method commonly used in drug development research. Development of new algorithms and/or new knowledge will bring beneficial tools to all clinical pharmacologists.