Lamictal Dosage

Generic name: lamotrigine
Brand names: Lamictal, Lamictal ODT, Lamictal XR
Drug class: Triazine anticonvulsants

Medically reviewed by  A Ras MD.

Recommended Adult Dosing

Dosage forms:  TAB: 25 mg, 100 mg, 150 mg, 200 mg; ODT: 25 mg, 50 mg, 100 mg, 200 mg; CHEWABLE: 2 mg, 5 mg, 25 mg; blue convenience pack (tab); blue convenience pack (ODT); green convenience pack (tab); green convenience pack (ODT); orange convenience pack (tab); orange convenience pack (ODT)

Bipolar I disorder, maintenance tx

[monotherapy]

Dose: 200 mg PO qd; Start: orange starter pack (25 mg PO qd x2wk, then 50 mg PO qd x2wk, then 100 mg PO qd x1wk); Max: 200 mg/day; Info: dose adjustment may be needed during pregnancy and/or postpartum; taper dose over 2wk to D/C

[valproate adjunct]

Dose: 100 mg PO qd; Start: blue starter pack (25 mg PO qod x2wk, then 25 mg PO qd x2wk, then 50 mg PO qd x1wk); Max: 100 mg/day; Info: applies to any regimen containing a valproic acid derivative; dose adjustment may be needed during pregnancy and/or postpartum; taper dose over 2wk to D/C

[enzyme-inducing AED adjunct]

Dose: 200 mg PO bid; Start: green starter pack (50 mg PO qd x2wk, then 50 mg PO bid x2wk, then 100 mg PO bid x1wk), then 150 mg PO bid x1wk; Max: 400 mg/day; Info: enzyme-inducing AEDs incl. carbamazepine, phenytoin, phenobarbital, primidone; dose adjustment may be needed during pregnancy and/or postpartum; taper dose over 2wk to D/C

[non-valproate, non-inducing AED adjunct]

Dose: 200 mg PO qd; Start: orange starter pack (25 mg PO qd x2wk, then 50 mg PO qd x2wk, then 100 mg PO qd x1wk); Max: 200 mg/day; Info: dose adjustment may be needed during pregnancy and/or postpartum; taper dose over 2wk to D/C

Partial seizures

[conversion to monotherapy]

Dose: 250 mg PO bid; Start: see pkg insert for titration schedule; Info: for conversion to lamotrigine monotherapy from carbamazepine, phenytoin, phenobarbital, primidone or valproate monotherapy; not for initial monotherapy or conversion from other anticonvulsants not listed; dose adjustment may be needed during pregnancy and/or postpartum; taper dose over 2wk to D/C

[valproate adjunct]

Dose: 100-400 mg/day PO divided qd-bid; Start: blue starter pack (25 mg PO qod x2wk, then 25 mg PO qd x2wk, then 50 mg PO qd x1wk), then incr. by 25-50 mg/day q1-2wk; Max: 400 mg/day; 200 mg/day w/ valproate alone; Info: applies to any regimen containing a valproic acid derivative; dose adjustment may be needed during pregnancy and/or postpartum; taper dose over 2wk to D/C

[enzyme-inducing AED adjunct]

Dose: 150-250 mg PO bid; Start: green starter pack (50 mg PO qd x2wk, then 50 mg PO bid x2wk, then 100 mg PO bid x1wk), then incr. by 100 mg/day q1-2wk; Max: 700 mg/day; Info: benefit of doses >500 mg/day not established; enzyme-inducing AEDs incl. carbamazepine, phenytoin, phenobarbital, primidone; dose adjustment may be needed during pregnancy and/or postpartum; taper dose over 2wk to D/C

[non-valproate, non-inducing AED adjunct]

Dose: 225-375 mg/day PO divided bid; Start: orange starter pack (25 mg PO qd x2wk, then 50 mg PO qd x2wk, then 100 mg PO qd x1wk), then incr. by 50 mg/day q1-2wk; Max: 375 mg/day; Info: dose adjustment may be needed during pregnancy and/or postpartum; taper dose over 2wk to D/C

Seizures, Lennox-Gastaut syndrome

[valproate adjunct]

Dose: 100-400 mg/day PO divided qd-bid; Start: blue starter pack (25 mg PO qod x2wk, then 25 mg PO qd x2wk, then 50 mg PO qd x1wk), then incr. by 25-50 mg/day q1-2wk; Max: 400 mg/day; 200 mg/day w/ valproate alone; Info: applies to any regimen containing a valproic acid derivative; dose adjustment may be needed during pregnancy and/or postpartum; taper dose over 2wk to D/C

[enzyme-inducing AED adjunct]

Dose: 150-250 mg PO bid; Start: green starter pack (50 mg PO qd x2wk, then 50 mg PO bid x2wk, then 100 mg PO bid x1wk), then incr. by 100 mg/day q1-2wk; Max: 700 mg/day; Info: benefit of doses >500 mg/day not established; enzyme-inducing AEDs incl. carbamazepine, phenytoin, phenobarbital, primidone; dose adjustment may be needed during pregnancy and/or postpartum; taper dose over 2wk to D/C

[non-valproate, non-inducing AED adjunct]

Dose: 225-375 mg/day PO divided bid; Start: orange starter pack (25 mg PO qd x2wk, then 50 mg PO qd x2wk, then 100 mg PO qd x1wk), then incr. by 50 mg/day q1-2wk; Max: 375 mg/day; Info: dose adjustment may be needed during pregnancy and/or postpartum; taper dose over 2wk to D/C

Seizures, primary generalized tonic clonic

[valproate adjunct]

Dose: 100-400 mg/day PO divided qd-bid; Start: blue starter pack (25 mg PO qod x2wk, then 25 mg PO qd x2wk, then 50 mg PO qd x1wk), then incr. by 25-50 mg/day q1-2wk; Max: 400 mg/day; 200 mg/day w/ valproate alone; Info: applies to any regimen containing a valproic acid derivative; dose adjustment may be needed during pregnancy and/or postpartum; taper dose over 2wk to D/C

[enzyme-inducing AED adjunct]

Dose: 150-250 mg PO bid; Start: green starter pack (50 mg PO qd x2wk, then 50 mg PO bid x2wk, then 100 mg PO bid x1wk), then incr. by 100 mg/day q1-2wk; Max: 700 mg/day; Info: benefit of doses >500 mg/day not established; enzyme-inducing AEDs incl. carbamazepine, phenytoin, phenobarbital, primidone; dose adjustment may be needed during pregnancy and/or postpartum; taper dose over 2wk to D/C

[non-valproate, non-inducing AED adjunct]

Dose: 225-375 mg/day PO divided bid; Start: orange starter pack (25 mg PO qd x2wk, then 50 mg PO qd x2wk, then 100 mg PO qd x1wk), then incr. by 50 mg/day q1-2wk; Max: 375 mg/day; Info: dose adjustment may be needed during pregnancy and/or postpartum; taper dose over 2wk to D/C

Migraine headache w/ aura prophylaxis

[100 mg PO qd]

Start: 25 mg PO qd x2wk, may incr. by 25 mg/day qwk; Info: dose adjustment may be needed during pregnancy and/or postpartum; taper dose over 2wk to D/C; not 1st-line tx

Neuropathic pain, diabetic

[200-400 mg/day PO divided qd-bid]

Start: 25 mg PO qd x2wk, then 50 mg/day PO divided qd-bid x2wk, then may incr. dose qwk; Max: 400 mg/day; Info: dose adjustment may be needed during pregnancy and/or postpartum; taper dose over 2wk to D/C

Renal dosing

[adjust dose amount]

CrCl 10-50: decr. usual dose by 25%; CrCl <10: 100 mg qod

HD: 100 mg x1 after each dialysis; no supplement; PD: 100 mg qod; supplement not defined

Hepatic dosing

[adjust dose amount]

mod-severe impairment: decr. dose 25%; severe impairment w/ ascites: decr. dose 50%

Recommended Peds Dosing

Dosage forms:  TAB: 25 mg, 100 mg, 150 mg, 200 mg; ODT: 25 mg, 50 mg, 100 mg, 200 mg; CHEWABLE: 2 mg, 5 mg, 25 mg; blue convenience pack (tab); blue convenience pack (ODT); green convenience pack (tab); green convenience pack (ODT); orange convenience pack (tab); orange convenience pack (ODT)

Partial seizures

[valproate adjunct, 2-12 yo]

Dose: 1-5 mg/kg/day PO divided qd-bid; 1-3 mg/kg/day PO divided qd-bid w/ valproate alone; Start: 0.15 mg/kg/day PO divided qd-bid x2wk, then 0.3 mg/kg/day PO divided qd-bid x2wk, then incr. by 0.3 mg/kg/day q1-2wk; Max: 200 mg/day; Info: round dose down to nearest whole tab size; pts <30 kg may need up to 50% higher maint. dose; applies to any regimen containing a valproic acid derivative; taper dose over 2wk to D/C

[valproate adjunct, >12 yo]

Dose: 100-400 mg/day PO divided qd-bid; Start: blue starter pack (25 mg PO qod x2wk, then 25 mg PO qd x2wk, then 50 mg PO qd x1wk), then incr. by 25-50 mg/day q1-2wk; Max: 400 mg/day; 200 mg/day if w/ valproate alone; Info: applies to any regimen containing a valproic acid derivative; taper dose over 2wk to D/C

[enzyme-inducing AED adjunct, 2-12 yo]

Dose: 5-15 mg/kg/day PO divided bid; Start: 0.6 mg/kg/day PO divided bid x2wk, then 1.2 mg/kg/day PO divided bid x2wk, then incr. by 1.2 mg/kg/day q1-2wk; Max: 400 mg/day; Info: round dose down to nearest whole tab size; pts <30 kg may need up to 50% higher maint. dose; enzyme-inducing AEDs incl. carbamazepine, phenytoin, phenobarbital, primidone; taper dose over 2wk to D/C

[enzyme-inducing AED adjunct, >12 yo]

Dose: 150-250 mg PO bid; Start: green starter pack (50 mg PO qd x2wk, then 50 mg PO bid x2wk, then 100 mg PO bid x1wk), then incr. by 100 mg/day q1-2wk; Max: 700 mg/day; Info: benefit of doses >500 mg/day has not been established; enzyme-inducing AEDs incl. carbamazepine, phenytoin, phenobarbital, primidone; taper dose over 2wk to D/C

[non-valproate, non-inducing AED adjunct, 2-12 yo]

Dose: 4.5-7.5 mg/kg/day PO divided bid; Start: 0.3 mg/kg/day PO divided bid x2wk, then 0.6 mg/kg/day PO divided bid x2wk, then incr. by 0.6 mg/kg/day q1-2wk; Max: 300 mg/day; Info: round dose down to nearest whole tab size; pts <30 kg may need up to 50% higher maint. dose; taper dose over 2wk to D/C

[non-valproate, non-inducing AED adjunct, >12 yo]

Dose: 225-375 mg/day PO divided bid; Start: orange starter pack (25 mg PO qd x2wk, then 50 mg PO qd x2wk, then 100 mg PO qd x1wk), then incr. by 50 mg/day q1-2wk; Max: 375 mg/day; Info: taper dose over 2wk to D/C

Seizures, Lennox-Gastaut syndrome

[valproate adjunct, 2-12 yo]

Dose: 1-5 mg/kg/day PO divided qd-bid; 1-3 mg/kg/day PO divided qd-bid w/ valproate alone; Start: 0.15 mg/kg/day PO divided qd-bid x2wk, then 0.3 mg/kg/day PO divided qd-bid x2wk, then incr. by 0.3 mg/kg/day q1-2wk; Max: 200 mg/day; Info: round dose down to nearest whole tab size; pts <30 kg may need up to 50% higher maint. dose; applies to any regimen containing a valproic acid derivative; taper dose over 2wk to D/C

[valproate adjunct, >12 yo]

Dose: 50-200 mg PO bid; Start: blue starter pack (25 mg PO qod x2wk, then 25 mg PO qd x2wk, then 50 mg PO qd x1wk), then incr. by 25-50 mg/day q1-2wk; Max: 400 mg/day; 200 mg/day if w/ valproate alone; Info: applies to any regimen containing a valproic acid derivative; taper dose over 2wk to D/C

[enzyme-inducing AED adjunct, 2-12 yo]

Dose: 5-15 mg/kg/day PO divided bid; Start: 0.6 mg/kg/day PO divided bid x2wk, then 1.2 mg/kg/day PO divided bid x2wk, then incr. by 1.2 mg/kg/day q1-2wk; Max: 400 mg/day; Info: round dose down to nearest whole tab size; pts <30 kg may need up to 50% higher maint. dose; enzyme-inducing AEDs incl. carbamazepine, phenytoin, phenobarbital, primidone; taper dose over 2wk to D/C

[enzyme-inducing AED adjunct, >12 yo]

Dose: 150-250 mg PO bid; Start: green starter pack (50 mg PO qd x2wk, then 50 mg PO bid x2wk, then 100 mg PO bid x1wk), then incr. by 100 mg/day q1-2wk; Max: 700 mg/day; Info: benefit of doses >500 mg/day not established; enzyme-inducing AEDs incl. carbamazepine, phenytoin, phenobarbital, primidone; taper dose over 2wk to D/C

[non-valproate, non-inducing AED adjunct, 2-12 yo]

Dose: 4.5-7.5 mg/kg/day PO divided bid; Start: 0.3 mg/kg/day PO divided bid x2wk, then 0.6 mg/kg/day PO divided bid x2wk, then incr. by 0.6 mg/kg/day q1-2wk; Max: 300 mg/day; Info: round dose down to nearest whole tab size; pts <30 kg may need up to 50% higher maint. dose; taper dose over 2wk to D/C

[non-valproate, non-inducing AED adjunct, >12 yo]

Dose: 225-375 mg/day PO divided bid; Start: orange starter pack (25 mg PO qd x2wk, then 50 mg PO qd x2wk, then 100 mg PO qd x1wk), then incr. by 50 mg/day q1-2wk; Max: 375 mg/day; Info: taper dose over 2wk to D/C

Seizures, primary generalized tonic clonic

[valproate adjunct, 2-12 yo]

Dose: 1-5 mg/kg/day PO divided qd-bid; 1-3 mg/kg/day PO divided qd-bid w/ valproate alone; Start: 0.15 mg/kg/day PO divided qd-bid x2wk, then 0.3 mg/kg/day PO divided qd-bid x2wk, then incr. by 0.3 mg/kg/day q1-2wk; Max: 200 mg/day; Info: round dose down to nearest whole tab size; pts <30 kg may need up to 50% higher maint. dose; applies to any regimen containing a valproic acid derivative; taper dose over 2wk to D/C

[valproate adjunct, >12 yo]

Dose: 50-200 mg PO bid; Start: blue starter pack (25 mg PO qod x2wk, then 25 mg PO qd x2wk, then 50 mg PO qd x1wk), then incr. by 25-50 mg/day q1-2wk; Max: 400 mg/day; 200 mg/day if w/ valproate alone; Info: applies to any regimen containing a valproic acid derivative; taper dose over 2wk to D/C

[enzyme-inducing AED adjunct, 2-12 yo]

Dose: 5-15 mg/kg/day PO divided bid; Start: 0.6 mg/kg/day PO divided bid x2wk, then 1.2 mg/kg/day PO divided bid x2wk, then incr. by 1.2 mg/kg/day q1-2wk; Max: 400 mg/day; Info: round dose down to nearest whole tab size; pts <30 kg may need up to 50% higher maint. dose; enzyme-inducing AEDs incl. carbamazepine, phenytoin, phenobarbital, primidone; taper dose over 2wk to D/C

[enzyme-inducing AED adjunct, >12 yo]

Dose: 150-250 mg PO bid; Start: green starter pack (50 mg PO qd x2wk, then 50 mg PO bid x2wk, then 100 mg PO bid x1wk), then incr. by 100 mg/day q1-2wk; Max: 700 mg/day; Info: benefit of doses >500 mg/day not established; enzyme-inducing AEDs incl. carbamazepine, phenytoin, phenobarbital, primidone; taper dose over 2wk to D/C

[non-valproate, non-inducing AED adjunct, 2-12 yo]

Dose: 4.5-7.5 mg/kg/day PO divided bid; Start: 0.3 mg/kg/day PO divided bid x2wk, then 0.6 mg/kg/day PO divided bid x2wk, then incr. by 0.6 mg/kg/day q1-2wk; Max: 300 mg/day; Info: round dose down to nearest whole tab size; pts <30 kg may need up to 50% higher maint. dose; taper dose over 2wk to D/C

[non-valproate, non-inducing AED adjunct, >12 yo]

Dose: 225-375 mg/day PO divided bid; Start: orange starter pack (25 mg PO qd x2wk, then 50 mg PO qd x2wk, then 100 mg PO qd x1wk), then incr. by 50 mg/day q1-2wk; Max: 375 mg/day; Info: taper dose over 2wk to D/C

Renal dosing

[adjust dose amount]

CrCl <10: decr. usual dose by 50%

HD: decr. usual dose by 50%; supplement after dialysis not defined; PD: decr. usual dose by 50%; supplement not defined

Hepatic dosing

[adjust dose amount]

mod-severe impairment: decr. dose 25%; severe impairment w/ ascites: decr. dose 50%

SRC: NLM .