Adult & adolescent >12 yr Epilepsy: Monotherapy Initially 25 mg once daily for 2 wk followed by 50 mg once daily for 2 wk. Increase dose by max 50-100 mg every 1-2 wk.
Maintenance: 100-200 mg/day once daily or as 2 divided doses.
Add-on therapy [w/ valproate w/ or w/o other antiepileptic drugs (AED)] Initially 25 mg every alternate day for 2 wk followed by 25 mg once daily for 2 wk. Increase dose by max 25-50 mg every 1-2 wk. Maintenance: 100-200 mg/day once daily or as 2 divided doses.
Add-on therapy [w/ concomitant AEDs or other medications that induce lamotrigine glucuronidation w/ or w/o other AEDs (except valproate)] Initially 50 mg once daily for 2 wk followed by 100 mg/day in 2 divided doses for 2 wk. Increase dose by max 100 mg every 1-2 wk. Maintenance: 200-400 mg/day in 2 divided doses.
Add-on therapy [w/ other medications that do not significantly inhibit or induce lamotrigine glucuronidation] Initially 25 mg once daily for 2 wk followed by 50 mg once daily for 2 wk. Increase dose by max 50-100 mg every 1-2 wk. Maintenance: 100-200 mg/day once daily or as 2 divided doses.
Childn 2-12 yr Epilepsy: Add-on therapy (w/ valproate w/ or w/o other AEDs) Initially 0.15 mg/kg/day once daily for 2 wk followed by 0.3 mg/kg/day once daily for 2 wk. Increase dose by max 0.3 mg/kg every 1-2 wk. Maintenance: 1-5 mg/kg/day once daily or as 2 divided doses. Max: 200 mg/day.
Concomitant AEDs or other medications that induce lamotrigine glucuronidation w/ or w/o other AEDs (except valproate) Initially 0.6 mg/kg/day in 2 divided doses for 2 wk followed by 1.2 mg/kg/day in 2 divided doses for 2 wk. Increase dose by max 1.2 mg/kg every 1-2 wk. Maintenance: 5-15 mg/kg/day once daily or in 2 divided doses. Max: 400 mg/day.
Adult ≥18 yr Bipolar disorder: Monotherapy or adjunctive therapy w/ other medications that do not significantly induce or inhibit lamotrigine glucuronidation Initially 25 mg once daily for 2 wk followed by 50 mg once daily or in 2 divided doses for 2 wk. Increase dose to 100 mg/day in wk 5. Target stabilisation dose: 200 mg/day once daily or as 2 divided doses. W/draw other psychotropic medications once target daily maintenance stabilisation dose is achieved.
Adjunct therapy w/ lamotrigine glucuronidation inhibitors (eg, valproate) Initially 25 mg every alternate day for 2 wk followed by 25 mg once daily for 2 wk. Increase dose to 50 mg once daily or in 2 divided doses in wk 5. Target stabilisation dose: 100 mg/day once daily or in 2 divided doses. Max daily dose: 200 mg.
Adjunct therapy w/ lamotrigine glucuronidation inducers w/o taking inhibitors (eg, valproate) Initially 50 mg once daily for 2 wk followed by 100 mg/day in 2 divided doses for 2 wk. Increase dose to 200 mg/day in 2 divided doses in wk 5. Increase dose to 300 mg/day in wk 6. Target stabilisation dose: 400 mg/day in 2 divided doses for wk 7.
Woman starting hormonal contraceptives concurrently w/ lamotrigine maintenance dose & not taking lamotrigine glucuronidation inducers Increase lamotrigine dose by 50-100 mg/day every wk, from time of hormonal contraceptive is started.
Woman stopping hormonal contraceptive during concurrent lamotrigine maintenance doses & not taking lamotrigine glucuronidation inducers Gradually decrease lamotrigine daily dose by 50-100 mg each wk over 3 wk.
Hepatic impairment: Moderate (Child-Pugh grade B) Reduce dose by 50%,
severe (Child-Pugh grade C) Reduce dose by 75%.