Anticonvulsant drugs are prescribed to treat a range of medical conditions in addition to seizure disorders, like epilepsy. Among those are bipolar disorder, fibromyalgia, and pain caused by nerve injuries (neuralgia) or other conditions.

Overall, study results showing how well anticonvulsants work in treating those three conditions are mixed, and vary by both specific drug and disorder. Other treatment options might work as well as or better than anticonvulsants. That said, some anticonvulsants have been linked to clear clinical benefits, and several have been approved by the Food and Drug Administration for treating bipolar disorder, nerve pain, or fibromyalgia.

Anticonvulsants can cause serious side effects, including an increased risk of suicide and life-threatening skin rashes. They can also cause dangerous interactions with other medications. Newer anticonvulsants marketed since the late 1990s have sometimes been touted as safer and posing less risk of adverse effects than older ones. No large, good quality studies have tested this directly, but small, short-term studies that compared the drugs don't support such a conclusion.  Taking cost, dosing convenience, effectiveness, safety, and adverse effects into consideration, we have chosen the following as Consumer Reports Health Best Buy Drugs if you and your doctor decide that an anticonvulsant might be appropriate:

• Generic carbamazepine – for treating the manic phases of bipolar disorder and for trigeminal neuralgia, a type of nerve pain that affects facial trigeminal nerves.
• Generic valproic acid or generic divalproex – for treating the manic phases of bipolar disorder.
• Generic lamotrigine – for treating the depressive phases of bipolar disorder.
• Generic gabapentin – for treating nerve pain associated with diabetes or herpes zoster infection (shingles), and for treating fibromyalgia.

This report was published in July 2011.

Note: If the price box contains a , that indicates the dose of that drug is available for a low monthly cost through programs offered by large chain stores. For example, Kroger, Sam's Club, Target, and Walmart offer a month's supply of selected generic drugs for $4 or a three-month supply for $10. Other chain stores, such as Costco, CVS, Kmart, and Walgreens, offer similar programs. Some programs have restrictions or membership fees, so check the details carefully for restrictions and to make sure your drug is covered.