Comparative Pharmacology
Head-to-head clinical analysis: LAMICTAL CD versus VALPROATE SODIUM.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LAMICTAL CD versus VALPROATE SODIUM.
LAMICTAL CD vs VALPROATE SODIUM
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Lamotrigine is a phenyltriazine anticonvulsant that stabilizes neuronal membranes by blocking voltage-sensitive sodium channels and inhibiting the presynaptic release of excitatory neurotransmitters such as glutamate and aspartate.
Increases GABA levels by inhibiting GABA transaminase and blocking voltage-gated sodium channels; also modulates T-type calcium channels.
Lamotrigine extended-release (LAMICTAL CD) for epilepsy: initial 50 mg orally once daily for 2 weeks, then 100 mg once daily for 2 weeks, then 200 mg once daily for 2 weeks, then 300 mg once daily for 2 weeks, then 400 mg once daily thereafter. For bipolar disorder: initial 25 mg once daily for 2 weeks, then 50 mg once daily for 2 weeks, then 100 mg once daily for 2 weeks, then 200 mg once daily thereafter.
10-15 mg/kg/day orally or intravenously in 2-3 divided doses; increase by 5-10 mg/kg/day weekly to therapeutic range of 50-100 mcg/mL. Maximum dose 60 mg/kg/day.
None Documented
None Documented
Terminal elimination half-life in adults is approximately 25.4 hours (range 14-50 hours) in healthy volunteers; reduced to 14.5 hours (range 12-20) with enzyme-inducing antiepileptics (e.g., carbamazepine, phenytoin), increased to 59 hours (range 30-90) with valproate, and prolonged in renal impairment.
Terminal elimination half-life is 9–16 hours in adults; may be shorter in children (5–12 hours) and prolonged in hepatic impairment or elderly (up to 18 hours). Neonatal half-life: 10–67 hours. Clinically, twice-daily dosing is typical.
Lamotrigine is primarily eliminated by hepatic metabolism, with approximately 94% of the dose excreted in urine as glucuronide conjugates (10% as unchanged drug) and 2% in feces.
Primarily renal (90% as glucuronide conjugates, 3-oxo derivative, and other metabolites; <3% unchanged). Biliary/fecal excretion accounts for <10%.
Category C
Category C
Anticonvulsant
Anticonvulsant