Adults

Initial dose 50 mg twice daily, increasing weekly by 50-100 mg/day up to a maintenance dose of 100-200 mg twice daily (maximum 400 mg/day).

Elderly

Similar to adults, but dosage adjustment may be necessary in elderly patients with reduced renal clearance. Caution advised.

Renal_impairment

For patients with mild to moderate renal impairment (CrCl >30 mL/min), no dose adjustment is generally needed. For severe renal impairment (CrCl ≤30 mL/min) and end-stage renal disease, a maximum daily dose of 300 mg is recommended. Hemodialysis removes lacosamide, so a supplemental dose may be considered after dialysis.

Onset

Within hours of administration, steady state concentrations typically reached within 3 days with twice-daily dosing.

Excretion

Mainly renal, with about 95% of the dose excreted in the urine (approximately 40% as unchanged drug and 30% as the O-desmethyl metabolite).

Half life

Approximately 13 hours.

Absorption

Rapid and complete oral absorption, bioavailability is approximately 100%. Peak plasma concentrations occur 1-4 hours post-oral administration.

Metabolism

Primarily eliminated by renal excretion, with approximately 40% as unchanged drug. The major metabolite is O-desmethyl-lacosamide, formed mainly by hydrolysis. Minor metabolism occurs via CYP2C19, CYP3A4, and CYP2B6.

Strong CYP2C19 inhibitors

Although lacosamide is mainly metabolized by hydrolysis, minor metabolism occurs via CYP2C19. Strong inhibitors of CYP2C19 (e.g., fluconazole, fluvoxamine) may lead to a modest increase in lacosamide exposure.

Alcohol and CNS depressants

May potentiate CNS depressant effects like dizziness and somnolence.

Drugs prolonging PR interval

Coadministration with other drugs known to prolong the PR interval (e.g., beta-blockers, calcium channel blockers, digoxin) should be used with caution, as lacosamide can cause PR interval prolongation.