Side Effects of Levetiracetam (Keppra)
Levetiracetam commonly causes behavioral side effects including irritability, mood changes, and in some cases, aggressive behavior, along with somnolence and dizziness as the most frequent neurological side effects. 1, 2
Common Side Effects
Neurological Side Effects
- Somnolence (drowsiness) - occurs in approximately 15% of patients and is one of the most common side effects 1
- Dizziness - affects about 9% of patients 1
- Ataxia (lack of muscle coordination) - reported in 3% of patients 1
- Vertigo - occurs in approximately 3% of patients 1
- Amnesia - reported in 2% of patients 1
Psychiatric/Behavioral Side Effects
- Irritability - reported in 6% of patients with certain seizure types 1
- Depression - occurs in approximately 4% of patients 1
- Nervousness - affects about 4% of patients 1
- Anxiety - reported in 2% of patients 1
- Hostility - occurs in approximately 2% of patients 1
- Emotional lability - reported in 2% of patients 1
- Mood swings - affects about 5% of patients with certain seizure types 1
Gastrointestinal Side Effects
- Anorexia (decreased appetite) - occurs in approximately 3% of patients 1
- Diarrhea - reported in 8% of patients with certain seizure types 1
Respiratory Side Effects
- Pharyngitis (sore throat) - affects about 6-7% of patients 1
- Rhinitis (nasal inflammation) - occurs in approximately 4% of patients 1
- Increased cough - reported in 2% of patients 1
- Sinusitis - affects about 2% of patients 1
Other Side Effects
- Asthenia (weakness) - common but specific percentage not provided in the evidence 1
- Fatigue - reported in 10% of patients with certain seizure types 1
- Diplopia (double vision) - occurs in approximately 2% of patients 1
Severe Side Effects
Serious Psychiatric Side Effects
- Severe psychiatric symptoms occur in approximately 7.8% of patients taking levetiracetam 2
- Hallucinations and delusions can occur 2
- Aggressive behavior and agitation are among the most common severe psychiatric manifestations 2
- Suicidal and self-harm behaviors have been reported in some patients 2
- Delirium, though rare, has been reported as a potential adverse effect 3
Management of Severe Side Effects
- Reducing the dose of levetiracetam may help control psychiatric symptoms 2
- Discontinuation of the drug may be necessary in severe cases 2
- Adding antipsychotic medications can help manage severe psychiatric symptoms 2
Onset of Side Effects
- Many neurological side effects (asthenia, somnolence, dizziness) tend to occur predominantly during the first 4 weeks of treatment 1
- Behavioral side effects may appear at any time during treatment 2
Overdose Information
- Levetiracetam overdose is generally associated with relatively mild symptoms 4
- However, severe cases can lead to obtundation and significant respiratory distress requiring intubation 4
- In one reported case, a patient who ingested 358 mg/kg (approximately 22,500 mg) experienced no significant adverse effects 4
Special Considerations
- Levetiracetam has a favorable pharmacokinetic profile with minimal drug-drug interactions 5
- It does not induce its own metabolism and is not metabolized through the P450 hepatic cytochrome system 5
- When used for oral loading in patients with epilepsy, 89% of patients reported no adverse effects, while 11% experienced transient irritability, imbalance, tiredness, or lightheadedness 6
- Levetiracetam is generally better tolerated than older antiepileptic drugs like phenytoin or valproic acid 6