What are the potential side effects of Keppra (levetiracetam)?

Common Side Effects of Levetiracetam (Keppra)

Levetiracetam commonly causes somnolence (15-26%), dizziness (9-10%), and behavioral side effects including irritability, mood changes, and depression, with approximately 89% of patients tolerating the medication without significant adverse effects.

Neurological Side Effects

• Somnolence/drowsiness: Most common side effect (15-26% of patients) 1, 2
• Dizziness: Occurs in 9-10% of patients 1
• Ataxia: Affects approximately 3% of patients 1
• Vertigo: Reported in about 3% of patients 1
• Amnesia: Occurs in about 2% of patients 1

Psychiatric/Behavioral Side Effects

• Irritability: Occurs in 6-12% of patients, particularly those with intellectual disability or psychiatric history 2, 1
• Depression: Affects 4-5% of patients 1
• Nervousness/anxiety: Reported in 4% of patients 1
• Hostility: Occurs in about 2% of patients 1
• Emotional lability: Affects approximately 2% of patients 1
• Mood swings: Reported in about 5% of patients 1

Gastrointestinal Side Effects

• Anorexia: Affects about 3% of patients 1
• Diarrhea: Occurs in approximately 8% of patients 1

Respiratory Side Effects

• Pharyngitis: Affects 6-14% of patients 1
• Rhinitis: Occurs in 4-13% of patients 1
• Increased cough: Reported in 2-11% of patients 1

Other Side Effects

• Asthenia/fatigue: Affects 10-15% of patients 1, 3
• Diplopia (double vision): Occurs in about 2% of patients 1
• Infection: Reported in some patients 3

Rare but Serious Side Effects

• Psychosis: Uncommon but documented 4
• Delirium: Rare adverse effect, particularly in elderly patients 5
• Catatonia: Very rare but reported 4
• Suicidal behavior: Rare but serious concern 4

Risk Factors for Behavioral Side Effects

Patients with the following characteristics are at higher risk for developing behavioral side effects that may require discontinuation of levetiracetam 6:

• History of psychiatric disorders
• Diagnosis of symptomatic generalized epilepsy
• Rapid titration of the medication

Monitoring Recommendations

• Monitor for behavioral changes, particularly in patients with psychiatric history
• Consider slower titration in high-risk patients
• Most side effects are mild to moderate in intensity and often resolve with continued treatment or dose adjustment
• Approximately 7% of patients may need to discontinue levetiracetam due to behavioral side effects 6

Overdose Information

• Levetiracetam overdose is generally well-tolerated with relatively mild symptoms in most cases
• However, severe cases can lead to respiratory depression requiring ventilatory support 7

Levetiracetam has a generally favorable safety profile compared to many other antiepileptic medications, with minimal drug interactions and no significant hepatic metabolism 3. Most adverse effects are mild and transient, though clinicians should be particularly vigilant about monitoring for behavioral changes, especially in patients with pre-existing psychiatric conditions.