The safety of anticonvulsant drugs is being highlighted again after the publication of a study in the Journal of the American Medical Association that found that some of these medicines might be linked with a higher risk of suicide. "This exploratory analysis suggests that the use of gabapentin, lamotrigine, oxcarbazepine, and tiagabine, compared with the use of topiramate, may be associated with an increased risk of suicidal acts or violent deaths," the study's abstract notes. Pfizer sells gabapentin as Neurontin, while Novartis sells oxcarbazepine as Trileptal.
The researchers, headed by a team from Brigham and Women's Hospital in Boston, looked at data in patients aged 15 years and older who began taking anticonvulsant therapy between July 2001 and December 2006 to assess the risk associated with individual drugs. The study identified 26 completed suicides, 801 attempted suicides, and 41 violent deaths in the 297,620 new episodes of treatment. "Gabapentin users had increased risk in subgroups of younger and older patients, patients with mood disorders, and patients with epilepsy or seizure when compared with carbamazepine," the abstract notes.
However, the study was not large enough to draw any deeper conclusions on the scale of risk between these drugs. Risks were "pretty much even" among these medicines, and "it's not easy to draw conclusions about which one is the most risky," researcher Elisabetta Patorno tells Reuters.
But Ewald Horwath, professor of psychiatry and behavioral sciences at the University of Miami Miller School of Medicine, says the study's findings may be somewhat misleading. He said it failed to place enough weight on why patients were being treated with these drugs in the first place, and pointed out that many were taking the anticonvulsants for bipolar disorder and depression, illnesses which are themselves "associated with higher suicide rates," reports HealthDay News.
In 2008, the FDA mandated warning labeling for anticonvulsant medications regarding the increased risk of suicidal thoughts and behaviors. The decision was based on a meta-analysis not sufficiently large to investigate individual drugs.