Side Effects
A comprehensive, evidence-based review of levetiracetam's adverse effect profile — neuropsychiatric, cognitive, and systemic.
FDA Safety Communication (2023)
The FDA has warned of a rare but serious drug reaction — Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) — associated with levetiracetam (Keppra, Keppra XR, Elepsia XR, Spritam) and clobazam. DRESS can be fatal and may begin as a rash but can rapidly progress to involve internal organs. All antiepileptic drugs also carry a class warning for suicidal thoughts and behaviours.
Neuropsychiatric Effects
These are the most clinically significant adverse effects of levetiracetam. They are often under-recognised and under-reported. Expand each item for mechanism and citations.
Cognitive Effects
Memory impairment
Difficulties with verbal and working memory have been reported in observational studies, though the effect is generally smaller than with older AEDs.
Attention & concentration
Reduced sustained attention and processing speed, particularly at higher doses.
Psychomotor slowing
Slowed reaction times and reduced cognitive processing speed, which may affect driving and occupational performance.
Systemic Effects
Fatigue & somnolence
Among the most common adverse effects; reported in up to 15% of patients in clinical trials.
Dizziness
Reported in approximately 9% of patients; may contribute to falls risk in elderly patients.
Infection risk
Nasopharyngitis and other infections reported at higher rates than placebo in clinical trials.
DRESS (rare but serious)
Drug Reaction with Eosinophilia and Systemic Symptoms — a rare but potentially fatal hypersensitivity reaction. FDA issued a safety communication in 2023.