Adults

Initial dose is typically 500 mg twice daily. This may be increased by 500 mg twice daily increments every 2 weeks up to a maximum of 1500 mg twice daily, depending on response and tolerability.

Elderly

Dosage adjustments may be necessary based on renal function. Initiate with a lower dose and titrate slowly.

Renal_impairment

Dosage reduction is required. Adjust dose based on creatinine clearance (e.g., lower daily dose or extended dosing interval).

Onset

Rapid, typically within hours of the first dose.

Excretion

Primarily excreted via the kidneys, with approximately 66% of the dose excreted unchanged in urine.

Half life

Approximately 7-9 hours in adults, shorter in children (5-6 hours).

Absorption

Rapid and almost complete absorption after oral administration. Peak plasma concentrations are usually reached within 1 hour.

Metabolism

Minimal metabolism, not extensively metabolized by hepatic cytochrome P450 system. Primarily hydrolyzed into an inactive metabolite.

Phenytoin

Levetiracetam does not significantly alter the pharmacokinetics of common antiepileptic drugs like phenytoin. However, some evidence suggests a minor decrease in Levetiracetam clearance with enzyme-inducing AEDs, usually not clinically significant.

Central Nervous System (CNS) Depressants

Concurrent use with alcohol or other CNS depressants may lead to additive sedative effects and increased dizziness or drowsiness.