Medication Safety: Labeling updates and new warnings, March 2008

FDA has issued an early communication regarding systemic adverse reactions, including respiratory compromise and death, associated with the use of botulinum toxins type A (Botox and Botox Cosmetic, Allergan) and type B (Myobloc, Solstice Neurosciences). These reactions occurred after the use of botulinum toxins types A and B for both FDA-approved (eg, blepharospasm, cervical dystonia, severe primary axillary hyperhydrosis) and non-FDA-approved (eg, cerebral palsy-associated limb spasticity) indications. FDA is reviewing safety data from the manufacturers of botulinum toxins type A and B; in the meantime, the agency recommends that healthcare professionals should be aware of the potential for systemic effects after botulinum administration, including dysphagia, dysphonia, weakness, dyspnea, and respiratory distress.

FDA has issued an alert for the antiepileptic drugs carbamazepine (Carbatrol, Shire; Equetro, Validus; Tegretol, Novartis; generic carbamazepine), felbamate (Felbatol, MedPointe), gabapentin (Neurontin, Pfizer; generic gabapentin), lamotrigine (Lamictal, GlaxoSmithKline; generic lamotrigine), levetiracetam (Keppra, UCB), oxcarbazepine (Trileptal, Novartis; generic oxcarbazepine), pregabalin (Lyrica, Pfizer), tiagabine (Gabitril, Cephalon), topiramate (Topamax, Ortho-McNeil), valproate (Depakote, Depakote ER, Depakene, and Depacon, Abbott; generic valproate), and zonisamide (Zonegran, Eisai; generic zonisamide). This alert warns healthcare professionals that patients being treated with any of these agents should be closely monitored for notable changes in behavior that could indicate the emergence or worsening of suicidal thoughts, suicidal behavior, or depression.

The labeling information for varenicline (Chantix, Pfizer) has been updated to include a warning that patients being treated with this agent for smoking cessation should be observed for serious neuropsychiatric symptoms, including changes in behavior, agitation, depressed mood, suicidal ideation, and suicidal behavior.