Epilepsy Drugs to Get Suicide Warnings, FDA ConfirmsJun 6, 2008 | Parker Waichman LLP
US regulators are very close to finalizing new suicide warnings for 11 epilepsy drugs, The Wall Street Journal reported today. This past January, the Food & Drug Administration (FDA) issued an Early Communication announcing a safety review of the epilepsy drugs after a study showed they increased patients' risk of suicidal thoughts and behavior.
The 11 epilepsy drugs slated for a new suicide warning are:
- Carbamazepine (marketed as Carbatrol, Equetro, Tegretol, Tegretol XR)
- Felbamate (marketed as Felbatol)
- Gabapentin (marketed as Neurontin)
- Lamotrigine (marketed as Lamictal)
- Levetiracetam (marketed as Keppra)
- Oxcarbazepine (marketed as Trileptal)
- Pregabalin (marketed as Lyrica)
- Tiagabine (marketed as Gabitril)
- Topiramate (marketed as Topamax)
- Valproate (marketed as Depakote, Depakote ER, Depakene, Depacon)
- Zonisamide (marketed as Zonegran)
In addition to treating epilepsy, the anti-seizure medications are used for a variety of other illnesses, including migraines, certain nerve-pain disorders, and psychiatric diseases such as bipolar disorder that themselves carry a risk of suicide.
The FDA began investigating if epilepsy drugs posed any suicide risk in 2005. In doing so, the FDA analyzed almost 200 studies of 11 anti-seizure drugs, some that have been on the market for decades. The studies tracked almost 28,000 people given epilepsy medications and another 16,000 given dummy pills.
According to the FDA, 0.43 percent of drug-treated patients experienced suicidal thoughts or behavior, compared with 0.22 percent of placebo-takers. The higher risk of suicidal thoughts and behaviors was observed at one week after starting a drug and continued to at least 24 weeks. The results were generally consistent among all the different drug products studied and were seen in all demographic subgroups. Overall, four people in the drug-treated groups committed suicide, and none in the placebo groups. For every 1,000 patients, about two more patients taking epilepsy drugs experienced suicidal thoughts than those who took placebo.
In an interview with The Wall Street Journal, Russell Katz, director the FDA's neuropharmacological drug division confirmed the suicide warnings are coming. "We are working on the labeling changes that we want to get to the companies," he said. An FDA advisory panel is slated to take up the issue of epilepsy drugs and suicide on July 10, but the Journal speculated the new warnings could come even sooner than that.
At least one drug maker, Pfizer Inc., is less than pleased at this development. Pfizer disputed the FDA's analysis in a forum this week sponsored by the Epilepsy Study Consortium in New York. Pfizer especially disputes the inclusion of Lyrica - one of the company's biggest growth drivers -on the FDA's warning list. Pfizer said that Lyrica accounted for only 6.3% of the total 142 suicidal events cited by the FDA analysis. But the FDA is sticking to its guns, and the new suicide warning will apply to all 11 epilepsy drugs.
Most other epilepsy drug makers are resigned to the label changes, according to the Journal. GlaxoSmithKline, the maker of Lamictal, approached the FDA this year to volunteer changes regarding possible suicidal-behavior risks. Other drug makers may have chosen not to challenge the FDA on suicide warnings because their medications are no longer as lucrative as they once were, as patents on many epilepsy drugs have, or are close to, expiring.