Levetiracetam
Class: anticonvulsant
Indications: seizure control – can be adjunctive treatment or first line in palliative care for focal seizures
Contraindications/cautions: monitor for behavioural changes, hepatic and renal impairment; check renal function prior to treatment; reduce dose in renal impairment
Adverse reactions: very common: fatigue, drowsiness, headache common: somnolence, asthenia, infection, GI disturbance, blurred vision, hostility, pruritis, rash, cough, vertigo
Metabolism/clearance: metabolised by hydrolysis. Fraction excreted unchanged in the urine is 0.
Interactions:
- increased clinical effect/toxicity of levetiracetam may occur with other drugs that are excreted by active tubular secretion e.g. probenecid
- increased clinical effect/toxicity of levetiracetam (due to increased blood concentrations) may occur with valproate
- decreased clinical effect/toxicity of levetiracetam (due to decreased blood concentrations) may occur with carbamazepine, phenobarbitone, phenytoin
- isolated reports of toxicity with carbamazepine, methotrexate, phenytoin
| Dosing: | |
|---|---|
| Oral/ IV: | 500 mg twice daily initially (reduce in renal impairment) can start with 250 mg bd – Maximum 1.5 g twice daily |
| subcut: | continuous subcut infusion is an alternative to BD IV administration |
| rectal: | not available |
Syringe driver: not available
Mechanism of action: inhibits Ca2+ currents and reduces the release of Ca2+ from intraneuronal stores. Reverses the reductions in GABA- and glycine-gated currents induced by zinc and β-carbolines
Onset: peak concentrations at 1.5 hours