Mechanism: The precise mechanism of action is unclear. Topiramate is thought to work by increasing inhibitory (GABA) neurotransmission and reducing stimulatory (glutamate) neurotransmission. It is available in oral form, and requires a slow upward titration of dose to minimize side effects.

Efficacy: Topiramate has been shown in two randomized controlled trials to significantly improve multiple drinking outcomes, compared to placebo. Over the course of a 14-week trial, topiramate significantly increased the proportion of volunteers with 28 consecutive days of abstinence or non-heavy drinking. In both studies, the differences between topiramate and placebo groups were still diverging at the end of the trial, suggesting that the maximum effect may not have been seen. The magnitude of topiramate’s effect may be larger than that for naltrexone or acamprosate. Importantly, efficacy was established in volunteers who were drinking at the time of starting medication.

Click here to return to Case 3