Comparative Pharmacology
Head-to-head clinical analysis: LAMICTAL versus TOPAMAX.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LAMICTAL versus TOPAMAX.
LAMICTAL vs TOPAMAX
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Lamotrigine is a triazine antiepileptic drug that inhibits voltage-sensitive sodium channels, stabilizing neuronal membranes and modulating presynaptic transmitter release of excitatory amino acids like glutamate and aspartate.
Antiepileptic; modulates voltage-gated sodium channels, enhances GABA-A activity, antagonizes AMPA/kainate glutamate receptors, weakly inhibits carbonic anhydrase.
Initial: 25 mg orally once daily for 2 weeks, then 50 mg once daily for 2 weeks, then 100 mg once daily for 1 week, then 150 mg twice daily or 200 mg twice daily (if taking valproate, reduced regimen).
Initial dose 25 mg orally twice daily; titrate by 25-50 mg weekly to effective dose; usual maintenance dose 200-400 mg/day divided twice daily; maximum 1600 mg/day.
None Documented
None Documented
14 hours (monotherapy); 7 hours (with enzyme-inducers); 30 hours (with valproate).
Terminal elimination half-life is 21 hours (range 18-23 hours). Linear pharmacokinetics. Half-life is prolonged in renal impairment (CrCl <70 mL/min: ~35 hours).
Renal (70% as glucuronide metabolites, 2% as unchanged drug); fecal (2%); biliary (minor).
Renal: ~70% (unchanged drug); remainder as metabolites. Biliary/fecal: minimal (<5%).
Category C
Category C
Anticonvulsant
Anticonvulsant