Oxcarbazepine, a medication available in generic form and as the brand Trileptal, is mainly prescribed for controlling seizures. Trileptal is classified as an anticonvulsant; it works by decreasing abnormal electrical activity in the brain. Both weight gain and weight loss are possible side effects of Trileptal. Trileptal has many other possible side effects, some serious, so ask your doctor about negative effects before taking this medicine.
Trileptal can be taken alone or in combination with other medicine to control certain types of seizures. It is approved for controlling partial seizures, also called focal seizures, in people with epilepsy, according to eMedTV. In contrast with generalized seizures that affect both sides of the brain at the same time, partial seizures affect only one part of the brain. Doctors also sometimes prescribe Trileptal to treat bipolar disorder.
PubMed Health, a website of the National Library of Medicine, lists weight gain but not weight loss as a possible side effect of Trileptal. Another National Library of Medicine website, DailyMed, shows the incidence of weight increase for adults in a clinical study with Trileptal as part of a combination therapy at 1 to 2 percent, depending on the dosage. Weight gain is not listed as a side effect in a study where Trileptal was the only treatment.
DailyMed lists weight loss as an adverse event that occurred in studies. While not specifying a percentage of participants experiencing this side effect, it lists percentages of people experiencing side effects that could lead to weight loss. In a study using Trileptal as the only treatment for adults, depending on the dosage, 7 to 22 percent of participants experienced nausea; 5 to 15 percent, vomiting; 5 to 7 percent, diarrhea; 3 to 5 percent, lack of appetite; 3 to 5 percent, abdominal pain; and 1 to 6 percent, indigestion. PubMed notes that people taking Trileptal also may experience heartburn and changes in the way food tastes.
Other Negative Effects
Trileptal can cause numerous other side effects, including difficulty concentrating, mood swings, back pain, muscle weakness, nosebleeds, vision changes, dizziness and drowsiness. One particularly serious possible side effect involves suicidal thoughts and behavior, which occurs in about 1 in 500 people taking this drug for various conditions, according to PubMed Health.