Lamictal Chewable Dispersible Tabs

≥18yrs: Not on enzyme-inducing antiepileptic drugs (EIAEDs, eg, phenytoin, carbamazepine, phenobarbital, primidone), or valproate: 25mg daily for 2 weeks, then 50mg daily for 2 weeks, then 100mg daily for 1 week, then to target dose of 200mg daily. Concomitant valproate: 25mg every other day for 2 weeks, then 25mg daily for 2 weeks, then 50mg daily for 1 week, then to target dose of 100mg daily. Concomitant EIAEDs and not valproate: 50mg daily for 2 weeks, then 100mg daily in divided doses for 2 weeks, then increase weekly by 100mg daily in divided doses to target dose of 400mg daily in divided doses. Discontinuing valproate: double lamotrigine dose over 2 weeks in equal weekly increments. Discontinuing EIAEDs: maintain lamotrigine dose for 1 week after discontinuing EIAEDs, then reduce lamotrigine dose by ½ over 2 weeks in equal weekly decrements then adjust as needed. Reevaluate periodically. Concomitant estrogen-containing oral contraceptives, hormone replacement therapy, lopinavir/ritonavir, or atazanavir/ritonavir: see full labeling. Hepatic impairment: if moderate or severe (w/o ascites) reduce dose by 25%; if severe (w. ascites) reduce dose by 50%.

Chew tabs: give only whole tabs, round dose down to nearest whole tab (may be swallowed whole, chewed, or mixed in water or diluted fruit juice). ODT: dissolve on tongue and swallow with or without water. Adding to antiepileptic drug (AED) regimens that include valproate: initially 25mg every other day for 2 weeks, then 25mg once daily for 2 weeks; may increase by 25–50mg/day at 1–2 week intervals; usual maintenance 100–400mg/day in 1 or 2 divided doses. Adding to valproate only: usual maintenance 100–200mg/day. Adding to AED regimens other than carbamazepine, phenytoin, phenobarbital, primidone, or valproate: initially 25mg once daily for 2 weeks; then 50mg once daily for 2 weeks; may increase by 50mg/day at 1–2 week intervals; usual maintenance 225–375mg/day in 2 divided doses. Adding to AED regimens without valproate: initially 50mg per day for 2 weeks, then 100mg daily in 2 divided doses for 2 weeks; may increase by 100mg/day at 1–2 week intervals; usual maintenance 300–500mg/day in 2 divided doses. Converting from one AED (not valproate) to lamotrigine monotherapy (first titrate lamotrigine, then withdraw AED): initially 50mg per day for 2 weeks, then 100mg daily in 2 divided doses for 2 weeks; may increase by 100mg/day at 1–2 week intervals to 500mg/day in 2 divided doses. Then reduce AED dose by 20% per week for 4 weeks. Converting from valproate to lamotrigine monotherapy: see full labeling. Concomitant estrogen-containing oral contraceptives, hormone replacement therapy, lopinavir/ritonavir, or atazanavir/ritonavir: see full labeling. Hepatic impairment: if moderate or severe (w/o ascites) reduce dose by 25%; if severe (w. ascites) reduce dose by 50%.