Comparative Pharmacology
Head-to-head clinical analysis: DEPAKOTE versus LAMICTAL CD.
Head-to-head clinical analysis: DEPAKOTE versus LAMICTAL CD.
DEPAKOTE vs LAMICTAL CD
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Increases GABA levels by inhibiting GABA transaminase and succinic semialdehyde dehydrogenase; also blocks voltage-gated sodium channels and T-type calcium channels.
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.
Initial dose 750 mg/day PO in divided doses; increase by 250-500 mg/day every 3-7 days; maintenance dose 1000-2000 mg/day PO divided BID or TID; maximum 60 mg/kg/day.
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.
None Documented
None Documented
Terminal: 9-16 hours (mean 12 h); extended with hepatic dysfunction, co-administered enzyme inhibitors, or in elderly.
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.
Renal: <3% as unchanged drug; >95% as metabolites (glucuronide conjugates, oxidation products). Biliary/fecal: minor, <5%.
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.
Category C
Category C
Anticonvulsant
Anticonvulsant