Levetiracetam is a second-generation antiepileptic drug (AED) belonging to the racetam class. It is a pyrrolidone derivative with a unique mechanism of action, distinct from other AEDs. It is widely used as monotherapy or adjunctive therapy for the management of focal (partial-onset) seizures with or without secondary generalization, myoclonic seizures, and primary generalized tonic-clonic seizures. It is characterized by favorable pharmacokinetics, including rapid and complete absorption, linear kinetics, minimal protein binding, and a low potential for drug-drug interactions.
Adult: Adjunctive Therapy: Start at 500 mg twice daily (1000 mg/day). Can be increased by 500 mg twice daily every 2-4 weeks. Effective dose range: 1000-3000 mg/day. Monotherapy: Start at 250 mg twice daily, titrate to 500 mg twice daily after 2 weeks.
Note: Tablets can be taken with or without food. Swallow whole with a glass of water. Do not crush or chew unless specified (e.g., oral solution). For patients unable to swallow, tablets can be dispersed in a small amount of water immediately before use. Maintain consistent dosing schedule.
The exact mechanism is not fully elucidated but is distinct from other antiepileptic drugs. It does not act on traditional targets like sodium channels, GABA, or glutamate receptors. Its primary action is believed to be modulation of synaptic neurotransmitter release via binding to the synaptic vesicle protein 2A (SV2A).
Pregnancy: Pregnancy Category C (US FDA). Data from pregnancy registries do not show a clear increase in major congenital malformations. However, all AEDs carry a risk. Benefits of seizure control must be weighed against potential fetal risk. Folate supplementation is recommended. Monitor drug levels as pharmacokinetics may change during pregnancy.
Driving: May impair ability to drive or operate machinery. Patients should not drive until they are certain levetiracetam does not affect them adversely, especially during dose titration. Warn about dizziness and somnolence.
| Other CNS Depressants (e.g., Alcohol, Benzodiazepines, Opioids, Barbiturates) | Additive CNS depression, increased risk of somnolence, dizziness, and impaired coordination. | Moderate |
| Probenecid | Inhibits renal tubular secretion of the primary inactive metabolite, increasing its plasma levels. Clinical significance for levetiracetam itself is minimal. | Minor |
| Methotrexate | May reduce renal clearance of methotrexate's primary metabolite, 7-hydroxymethotrexate. Monitor for methotrexate toxicity. | Moderate |
| Oral Contraceptives (Ethinyl Estradiol, Levonorgestrel) | No clinically significant pharmacokinetic interaction. Contraceptive efficacy is not reduced. | None |