Pharmacology · Antiseizure medicines
Levetiracetam !
A widely used antiseizure medicine with few drug interactions. It binds a synaptic vesicle protein and can cause irritability or mood changes.
Updated 2026-11-01
The figure shows levetiracetam bound to human SV2A, a membrane protein of the synaptic vesicles.
Mechanism of action
Levetiracetam binds SV2A, a protein in the membrane of synaptic vesicles that helps regulate their fusion and the release of neurotransmitters. How this binding stops seizures is not fully understood, but the strength of binding of related molecules matches their antiseizure potency.
- Enters the nerve terminal and binds SV2A on synaptic vesicles
- Vesicle release is modulated
- Bursts of transmitter release are dampened
- Seizures are less likely to start and spread
Pharmacokinetics
- Absorption
- Rapidly and almost completely absorbed by mouth; also given intravenously
- Metabolism
- Not extensively metabolized; partly by enzymatic hydrolysis, not by liver cytochrome P450 enzymes
- Elimination
- Mostly unchanged in the urine; the dose is adjusted in kidney disease
- Half-life
- About 7 hours in adults
Indications
- Focal seizures, myoclonic seizures of juvenile myoclonic epilepsy and generalized tonic-clonic seizures Epilepsy and seizures →
- Intravenous use when the oral route is temporarily not possible
Adverse effects
Common
- Sleepiness and fatigue
- Dizziness and weakness
- Irritability and nervousness
Contraindications
- Hypersensitivity to levetiracetam (anaphylaxis or angioedema)
Key interactions
- Liver enzyme-metabolized antiseizure medicines
- Few pharmacokinetic interactions, because it does not use cytochrome P450
- Alcohol and other sedatives
- More sleepiness and slowed reactions
- Probenecid
- Reduces the kidney clearance of its inactive metabolite
What is monitored
- Mood, behaviour and suicidal thoughts
- Kidney function (creatinine clearance) to adjust the dose
- Seizure control in pregnancy, when levels may fall
Administration and safety
- Given by mouth or intravenously; the oral and intravenous doses are equivalent
- Some intravenous products come ready-mixed and must not be diluted further: check the product
- Withdrawn gradually: stopping suddenly can trigger seizures
Nursing care
- Ask the family to report irritability, aggression, low mood or strange thoughts
- Warn about sleepiness before driving or using machines
- Check kidney function in older adults
- Teach to report rash or swelling of the face
Pregnancy and breastfeeding
Levels may fall during pregnancy, so seizure control is followed closely, with specialist care.
Test yourself
Think of the answer, then tap the question to see it.
What is the binding site of levetiracetam?
SV2A, a glycoprotein of synaptic vesicles involved in their release of neurotransmitter.
Why does levetiracetam have few drug interactions?
It is not metabolized by liver cytochrome P450 enzymes and is mostly excreted unchanged in the urine.
Which adverse effects of levetiracetam should the family watch for?
Behavioural and mood changes: irritability, aggression, psychotic symptoms and suicidal thoughts.
What must be adjusted in a patient on levetiracetam with kidney failure?
The dose, according to creatinine clearance, because the drug is cleared by the kidneys.
Related drugs
Related conditions
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Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Levetiracetam: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2024); DailyMed - LEVETIRACETAM tablet, film coated (DailyMed (U.S. National Library of Medicine), 2026); DailyMed - LEVETIRACETAM injection (DailyMed (U.S. National Library of Medicine), 2026); eEML - Electronic Essential Medicines List (World Health Organization, 2025).
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Representative model, for educational purposes only.