Can Keppra Make You Sleepy?
Yes, levetiracetam (Keppra) commonly causes somnolence (sleepiness), which is one of its most frequently reported side effects.
Incidence of Somnolence
In Adults with Partial Onset Seizures
- 14.8% of levetiracetam-treated adults reported somnolence compared to 8.4% of placebo patients in controlled trials 1
- At higher doses (4000 mg/day without titration), approximately 45% of patients experienced somnolence 1
- Somnolence was considered serious in 0.3% of treated patients 1
- About 3% of patients discontinued treatment specifically due to somnolence, compared to 0.7% of placebo patients 1
In Pediatric Patients
- 22.8% of levetiracetam-treated children experienced somnolence, compared to 11% of placebo patients in controlled trials 1
Timing and Pattern
- Somnolence occurs most frequently within the first 4 weeks of treatment 1
- This side effect is part of a broader pattern of CNS adverse events that also includes fatigue (asthenia) and coordination difficulties 1
Comparative Safety Profile
Levetiracetam is generally better tolerated than older antiepileptic drugs like phenytoin or valproic acid, according to the American Academy of Neurology 2, 3
- The American Heart Association recommends levetiracetam over phenytoin or valproic acid due to its better overall tolerability profile 2
- When oral loading was used in patients with epilepsy, 89% reported no adverse effects, while only 11% experienced transient tiredness or lightheadedness 2
Clinical Significance
Severity and Management
- In most cases, somnolence is mild to moderate and transient 4, 2
- The dose was reduced in 1.4% of treated patients due to somnolence 1
- Only 0.3% of patients required hospitalization due to somnolence 1
Common Pitfalls to Avoid
- Do not assume somnolence will resolve immediately—it typically improves after the first month but may persist in some patients 1
- Higher doses carry substantially higher risk—the jump from standard dosing to 4000 mg/day increases somnolence rates from ~15% to ~45% 1
- Renal dysfunction requires dose adjustment as levetiracetam is predominantly renally eliminated, which could exacerbate CNS side effects if not properly adjusted 2
Additional Context from Research
Systematic reviews confirm that somnolence is the most statistically significant adverse effect associated with levetiracetam compared to placebo 5. A comprehensive safety review of 3,347 patients found that somnolence, along with asthenia and dizziness, occurred most frequently during the first month of treatment 6.