Breakthrough seizures after starting vilazodone for depression.

Vilazodone is a new selective serotonin reuptake inhibitor (SSRI) and serotonin 5-HT1a partial agonist that is approved by the United States Food and Drug Administration to treat major depression. SSRI-induced seizures are rare and are more likely to be associated with larger doses and severe symptoms such as those present in serotonin syndrome. Several case reports have implicated SSRIs, buspirone, or the combination of these agents as the cause of seizures, but these reports were confounded with either coingestions or doses that exceeded FDA recommendations. We describe a 22-year-old woman with a history of seizure disorder who had been seizure free for the previous 8 years and experienced two breakthrough seizures shortly after starting vilazodone. Her dose of vilazodone had recently been titrated to 40 mg/day when she experienced the first seizure. She was instructed to taper vilazodone over the next several days, then discontinue the drug, and then follow up with her neurologist. Based on the patient's history, physical examination, and recent dose increase, it was plausible that vilazodone was the cause of the seizures. Use of the Naranjo adverse drug reaction probability scale indicated a possible relationship (score of 4) between her development of seizures and vilazodone therapy. The pharmacodynamics of this particular class of SSRI has both proconvulsive and anticonvulsive mechanisms. This is of particular concern in patients with a history of seizure disorder who are starting antidepressive therapy. In persons with epilepsy who are taking vilazodone and experience breakthrough seizures, practitioners should consider this drug as a potential cause of these seizures. Thus, until future research and experience with vilazodone can provide a definitive answer, clinicians should be cautious when prescribing this medication to treat depression in patients with a history of seizure disorder.