Eslicarbazepine acetate (ESL), sold under the brand names Aptiom and Zebinix among others, is an anticonvulsant medication approved for use in Europe and the United States as monotherapy or as additional therapy for partial-onset seizures epilepsy.

Other fairly common side effects (1 to 10%) include impaired coordination, gastrointestinal disorders such as diarrhoea, nausea and vomiting, rash (1.1%), and hyponatremia (low sodium blood levels, 1.2%).

[10] Symptoms of overdosing are similar to adverse effects of standard doses: severe hyponatraemia, somnolence, uncoordinated/unsteady gait, hemiparesis (weakness of one side of the body), along with visual and gastrointestinal disturbances.

This drug combination also increased the risk for diplopia, impaired coordination and dizziness in a clinical study.

Biological half-life is 10 to 20 hours, and steady-state concentrations are reached after four to five days after start of the treatment.

[3][9] Persons with certain genetic variations in human leukocyte antigens (HLAs) are under increased risk of developing skin reactions such as acute generalized exanthematous pustulosis (AGEP), but also severe ones such as Stevens–Johnson and DRESS syndrome, under treatment with carbamazepine and drugs with related chemical structures.

In early 2009, Bial sold the marketing rights in Europe to the Japanese company Eisai.

[16] Like oxcarbazepine, ESL has potential uses for the treatment of trigeminal neuralgia[citation needed] and bipolar disorder.