Levetiracetam (Keppra) is generally well tolerated, and many people take it long-term without serious problems. The side effects that people most often notice early tend to improve over time. When people do have long-term effects, they’re usually related to mood, behavior, and very rare medical issues.
Common long-term side effects (less frequent than early side effects, but reported over time)
- Sleepiness, tiredness, dizziness, or headaches
- Coordination problems or imbalance
- Mood and behavior changes (see below)
- Possible weight changes (usually not dramatic)
Behavioral and mood effects (more notable with long-term use, especially in children/teens or people with prior psychiatric history)
- Irritability, agitation, aggression, anxiety, mood swings
- Depression or unusual changes in behavior
- In rare cases: psychosis or suicidal thoughts/behaviors (anytime, including long-term use)
Rare but important potential effects
- Severe allergic reactions (rash with peeling skin, trouble breathing; seek urgent care)
- Severe skin reactions (very rare)
- Blood problems (neutropenia, thrombocytopenia) — very uncommon; signs include fever, sore throat, easy bruising or unusual bleeding
- Severe confusion or hallucinations (less common but possible)
Notes on long-term safety
- Abruptly stopping levetiracetam can provoke seizures; it should be tapered under a clinician’s supervision.
- Most people do not have serious long-term organ toxicity from levetiracetam, partly because it is primarily excreted by the kidneys and not heavily metabolized by the liver.
What to do if you’re worried
- If you or a loved one notice new or worsening mood changes, agitation, aggression, depression, or thoughts of harming yourself, contact a clinician right away.
- Report any new rashes, fever, signs of infection, unusual bruising, or severe dizziness or confusion.
- Don’t stop the medicine suddenly without talking to your doctor—they can adjust the dose or switch medications if needed.
If you’d like, tell me your age group (adult vs child) or any other conditions you have, and I can tailor this to your situation and discuss which side effects are more likely or concerning for you. And of course, for medical advice specific to you, consult your healthcare provider.