Drugs used to treat epilepsy are also prescribed for other conditions including migraine, nerve pain disorders like shingles or fibromyalgia and psychiatric diseases like bipolar disorder. These diseases carry a risk of depression
define and suicidal tendencies in their own right.
The agency examined results from nearly 200 clinical studies covering Topamax by Johnson and Johnson, Lamictal by GlaxoSmithKline, Lyrica by Pfizer and Tegretol and Trileptal by Novartis AG. Of these, Topamaz is approved for migraine and Lyrica for shingles.
The study involved about 44000 patients, of which 28000 received the anti-epilepsy drugs and 16000 got a placebo. Those that received the drugs were 0.43% more likely towards suicidal behaviour or contemplation compared to 0.22% of the other group. This translates to two times more risk with the drugs than without. The increased risk was apparent within one week of starting on an anti-epileptic drug and continued beyond 24 weeks. Four persons in the drug-treated group committed suicide compared to none from the other.
Suicidal behaviour included completed suicides, thoughts or ideas and preparation like harming oneself, withdrawal or talking about death. The FDA has advised doctors to closely monitor patients currently on the drugs for possible behaviour change that could forewarn about depression and suicidal thoughts.
Depression is a commonly associated problem with pharmacologic treatment for chronic disorders. The present study has confirmed the heightened drug-related risk especially for epilepsy patients. The analysis did not extend beyond 24 weeks so that progression became difficult to estimate. But the FDA claims the pattern could be similar for all anti-epileptic drugs.
Skipping drugs could worsen seizures and patients need to obtain appropriate medical advice before attempting changes in medication. However, doctors need to consider the following factors in the light of the current report:
• The appropriate dosage to balance out the risk with the treatment objective
• Educate the patient and the family to watch out for changes in mood and behaviour
• Advise family and friends about suitable response during episodes like hurting oneself, talking about death, withdrawal, depression.
The FDA would seek better product information on the labelling. The agency would also discuss the data at an upcoming meeting of the advisory committee. It is clear manufacturers would need to include the suicidality risk on the product labels to inform patients and care givers.
In 2004, the FDA had issued stiff warnings on anti-depressants after an earlier analysis revealed increased risk of suicidal thoughts and behaviour in this class of drugs. The current report assumes much significance in this light.
The four companies were not available for comment.
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