Cenobamate (Xcopri), a new treatment option for adults with partial-onset seizures, has been approved by the Food and Drug Administration. It will be classified in the controlled substance schedule after review by the Drug Enforcement Administration, as it may be abused or lead to dependency.

Serious adverse effects occurred in a small percentage of patients during clinical trials of cenobamate. Cases of drug reaction with eosinophilia and systemic symptoms (DRESS; also called multiorgan hypersensitivity) and one death occurred with rapid dose titration (within a week or less). Symptoms of DRESS include fever, rash, lymphadenopathy, and/or facial swelling, in association with signs of other organ system involvement (for example, lymphadenopathy, hepatitis, nephritis, hematologic abnormalities, myocarditis, or myositis). An elevated eosinophil count may occur.

In the clinical trials, patients randomized to cenobamate had a higher incidence of shortened QT interval than those receiving placebo. Cenobamate is contraindicated in patients with familial short QT syndrome. Like all anticonvulsants, cenobamate carries a warning that suicidal behavior or ideation can occur. The most common adverse effects of cenobamate (in 10% or more of patients) include somnolence, dizziness, fatigue, double vision, and headache. Because of potential neurologic adverse effects, patients should not drive or operate machinery until they know how cenobamate affects them. Concomitant use of other central nervous system depressants or alcohol may have additive effects.

Drug interactions with other anticonvulsants may require dose adjustments: a decrease in the cenobamate dose with phenytoin, phenobarbital, or clobazam, and an increase with lamotrigine or carbamazepine. Cenobamate can also interact with drugs through the cytochrome P-450 (CYP) isoenzyme system. Patients receiving CYP2B6 or CYP3A substrates will need to increase the cenobamate dose, whereas those receiving CYP2C19 substrates will need to decrease it. Oral contraceptives may be less effective if taken concomitantly with cenobamate.

Nurses should evaluate patients at the first sign of hypersensitivity reactions, even if a rash is not present. If an alternative cause of the hypersensitivity reaction cannot be determined, cenobamate should be discontinued. Female patients who use oral contraceptives should use additional nonhormonal birth control. Nurses should instruct patients to swallow cenobamate tablets whole with liquid once daily.

For complete prescribing information for cenobamate, go to http://www.accessdata.fda.gov/drugsatfda_docs/label/2019/212839s000lbl.pdf.