NEW YORK (Reuters Health) – The anticonvulsant topiramate (Topamax) helps treat alcohol dependence, but serious side effects might limit its use, researchers say.
In their systematic review, Dr. Ann K. Shinn and Dr. Shelly F. Greenfield from Harvard Medical School in Boston found “robust” evidence supporting use of topiramate in alcohol-dependent patients.
On the other hand, they found no support for using topiramate to treat dependence on nicotine, cocaine, methamphetamines, benzodiazepines, opioids or Ecstasy.
According to their March 9th online paper in the Journal of Clinical Psychiatry, topiramate attenuates downstream midbrain dopamine release, which might help with addiction by lessening the reinforcing and rewarding properties of the abused substance.
The researchers identified 12 studies of topiramate for alcohol-related disorders published between 2002 and 2008. The strongest support came from a 14-week multicenter trial reported in 2007, they said. The double-blind study randomized 183 subjects to topiramate 300 mg/d and 188 to placebo. The results showed a mean difference of 8.4% in the number of heavy drinking days. Topiramate patients also had significant improvements in percent of abstinent days and drinks per drinking day.
Two other studies showed that topiramate may be more effective than oral naltrexone (Revia and Depade), which has FDA approval for treatment of alcohol dependence. By contrast, a trial comparing a low dose of topiramate to disulfiram (Antabuse) showed a higher relapse rate with topiramate.
Furthermore, two trials of topiramate for alcohol withdrawal failed to show that it was any better than diazepam (Valium) or lamotrigine (Lamictal).
But for dependence on nicotine, cocaine, methamphetamines, benzodiazepines, opioids or Ecstasy, the authors’ review of 14 studies was not encouraging.
In fact, topiramate actually appeared to accentuate the rewarding effects of nicotine and methamphetamine, which the researchers suggest could be due to inadequate topiramate dosing or treatment duration.
In most of the other studies, data were too limited to draw conclusions, although the authors call the results for cocaine dependence “promising.”
They point out that in the studies they reviewed – and in reports of the drug for other indications – more than 50% of patients treated with topiramate had paresthesias, and more than 20% had cognitive symptoms.
Based on their findings, Dr. Shinn and Dr. Greenfield call for “a blinded head-to-head randomized control trial comparing topiramate to the 3 FDA-approved medications for alcohol dependence (naltrexone, acamprosate, disulfiram) and placebo,” which they say should include factor analysis of genetic variants associated with treatment response.
Reference:
J Clin Psychiatry 2010.
