Common Side Effects of Lacosamide
Lacosamide, sold as Vimpat, causes side effects in many patients, especially at higher doses. Dizziness affects up to 31% of users, somnolence up to 24%, nausea up to 17%, and headache up to 14%. These often occur during dose increases and may lessen over time.[1][2]
Serious Side Effects and Risks
Atrial fibrillation or flutter happens in 0.4-1.1% of patients, with cardiac conduction issues like PR interval prolongation in 3-7%. Multiorgan hypersensitivity reactions, including DRESS syndrome, occur rarely but can be fatal. Suicidal thoughts affect 0.5%.[1][2][3] Higher doses (over 400 mg/day) raise risks of these cardiac and CNS effects.
How Dosage Affects Side Effects
Side effects increase with dose. Clinical trials show dizziness in 13% at 200 mg/day vs. 37% at 600 mg/day. Double-blind studies link nausea and vomiting to rapid titration. FDA labeling warns against exceeding 400 mg/day due to QT shortening and AV block risks.[1][2]
Side Effects by Dosage Level
- 200 mg/day: Mild dizziness (10-15%), low cardiac risk.
- 400 mg/day: Dizziness (25-30%), nausea (15%), PR prolongation (4%).
- 600 mg/day or higher: Severe dizziness (35-40%), ataxia, blurred vision; cardiac events double.[1][2]
What Happens If You Miss or Overdose
Missing a dose can cause seizures in epilepsy patients. Overdose (up to 10g reported) leads to coma, seizures, and cardiac arrest; treat with supportive care and hemodialysis.[1][3]
Managing Side Effects
Reduce dose or slow titration for dizziness/nausea. Monitor ECG for heart issues, especially with conduction disorders. Avoid abrupt stops to prevent withdrawal seizures. Consult a doctor before changes.[1][2]
Who Experiences More Side Effects
Elderly patients and those with heart disease face higher cardiac risks. Pediatric use (1 month+) shows similar profiles but more vomiting. Drug interactions with carbamazepine worsen effects.[1][3]
[1]: FDA Vimpat Label
[2]: Drugs.com Lacosamide Side Effects
[3]: RxList Vimpat