What the label lists and what reports show
Levetiracetam side effects
Levetiracetam's FDA label: “Most common adverse reactions (incidence ≥ 5% more than placebo) include: Adult patients: somnolence, asthenia, infection and dizziness ( 6.1 ) Pediatric patients: fatigue, aggression, nasal congestion, decreased appetite, and irritability ( 6.1 ) To report …” FAERS holds 132,823 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is fatigue (5,590 reports).
- Generic listed
Check it at the source: the levetiracetam FDA label on DailyMed (effective January 28, 2026, UCB, Inc.); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of KEPPRA?KEPPRA can cause serious side effects including: See " What is the most important information I should know about KEPPRA? " Call your healthcare provider right away if you have any of these symptoms: mood and behavior changes such as aggression, agitation, anger, anxiety, apathy, mood swings, depression, hostility, and irritability. A few people may get psychotic symptoms such as hallucinations (seeing or hearing things that are really not there), delusions (false or strange thoughts or beliefs) and unusual behavior. extreme sleepiness, tiredness, and weakness allergic reactions such as swelling of the face, lips, eyes, tongue, and throat, trouble swallowing or breathing, and hives. a skin rash. Serious skin rashes can happen after you start taking KEPPRA. […]
Source: FDA drug label, NDA021505 (Ucb Inc), as published by UCB, Inc., effective January 28, 2026 (SPL set 3ca9df05-a506-4ec8-a4fe-320f1219ab21), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common adverse reactions (incidence ≥ 5% more than placebo) include: Adult patients: somnolence, asthenia, infection and dizziness ( 6.1 ) Pediatric patients: fatigue, aggression, nasal congestion, decreased appetite, and irritability ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact UCB, Inc.
Table 5: Adverse Reactions in Pooled Placebo-Controlled, Adjunctive Studies in Pediatric Patients Ages 4 to 16 Years Experiencing Partial-Onset Seizures
| Reaction | KEPPRA (N=165) % | Placebo (N=131) % |
|---|---|---|
| Headache | 19 | 15 |
| Nasopharyngitis | 15 | 12 |
| Vomiting | 15 | 12 |
| Somnolence | 13 | 9 |
| Fatigue | 11 | 5 |
| Aggression | 10 | 5 |
| Cough | 9 | 5 |
| Nasal Congestion | 9 | 2 |
| Upper Abdominal Pain | 9 | 8 |
| Decreased Appetite | 8 | 2 |
| Abnormal Behavior | 7 | 4 |
| Dizziness | 7 | 5 |
| Irritability | 7 | 1 |
| Pharyngolaryngeal Pain | 7 | 4 |
| Diarrhea | 6 | 2 |
| Lethargy | 6 | 5 |
| Insomnia | 5 | 3 |
| Agitation | 4 | 1 |
| Anorexia | 4 | 3 |
| Head Injury | 4 | 0 |
| Altered Mood | 3 | 1 |
| Constipation | 3 | 1 |
| Contusion | 3 | 1 |
| Depression | 3 | 1 |
| Fall | 3 | 2 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following adverse reactions are discussed in more details in other sections of labeling: Behavior Abnormalities and Psychotic Symptoms [see Warnings and Precautions (5.1) ] Suicidal Behavior and Ideation [see Warnings and Precautions (5.2) ] Somnolence and Fatigue [see Warnings and Precautions (5.3) ] Anaphylaxis and Angioedema [see Warnings and Precautions (5.4) ] Serious Dermatological Reactions [see Warnings and Precautions (5.5) ] Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan Hypersensitivity [see Warnings and Precautions (5.6) ] Coordination Difficulties [see Warnings and Precautions (5.7) ] Hematologic Abnormalities [see Warnings and Precautions (5.9) ] Increase in Blood Pressure [see Warnings and Precautions (5.10) ] Most common adverse reactions (incidence ≥ 5% more than placebo) include: Adult patients: somnolence, asthenia, infection and dizziness ( 6.1 ) Pediatric patients: fatigue, aggression, nasal congestion, decreased appetite, and irritability ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact UCB, Inc. at 1-844-599-2273 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. …
Source: FDA drug label, NDA021505 (Ucb Inc), as published by UCB, Inc., effective January 28, 2026 (SPL set 3ca9df05-a506-4ec8-a4fe-320f1219ab21), via openFDA; the full label on DailyMed
What do FAERS reports show?
132,823 reports list levetiracetam among the medicines taken, each a report of something that happened, not proof the medicine caused it; 11,940 are coded as a death and 49,185 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 16 reactions below, 10 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Levetiracetam: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions