Lamotrigine (Lamictal)
Anticonvulsant (glutamate voltage-gated sodium channel blocker)
- Bipolar Depression1
- Borderline1
- Treatment resistant depression3
- OCD3
- Depersonalization2
- Cyclothymic disorder1
Features
Dosing
Usual titration is 25mg/d x 2wk, 50mg/d x 2wk, then 100mg/d. For patients under age 18 or on Depakote, start 25mg qod x 2wk, 25mg/d x 2wk then 50 mg/d. For patients on carbamazepine, phenytoin, phenobarbital, or primidone, start 50mg/d x 2wk, 100mg/d x 2wk, then 200 mg/d.
> Targets after titration (mg/d): Adults (100-250), geriatrics (50-150), children <12 (50-150), third trimester pregnancy (150-400). CBZ and estrogen-OCPs lowers it 40-50%, VPA doubles it, oxcarbazepine at > 1200 mg/d lowers it 30-50%. Lamotrigine may lower quetiapine levels 30%. Folic acid interferes with lamotrigine (but other folates do now). Serum levels not necessary but usually are 2-6 mg/l.
Management
Best tolerated mood stabilizer, great for cyclothymic temperament, works slowly (4-8 weeks) in acute bipolar depression but mainly prevents new episodes in bipolar. Not ideal as monotherapy in bipolar I as it is weak against mania, but great for monotherapy in bipolar II. ).
For treatment resistant depression, best in highly recurrent patients and those with long duration of illness (eight or more years) and more severe symptoms.
TOLERABILITY: Nausea, dizziness, imbalance improve with XR; bitter taste with ODT, word-finding problems improve with dose-reduction; and insomnia with morning dosing. XR/ODT $5/mth at costplusdrugs.com. Lamotrigine is safest bipolar med in pregnancy. Although not FDA approved in children (except for seizures), it is a good choice in childhood bipolar as it PREVENTS mood episodes, but need to use very low (CBZ) starter for children (see prescribing information; in teens use valproate dosing 25 qod).
RISKS: Severe rash (1/3000 chance, but have to stop if any rash in first 3 months, and 10% chance of benign rash). Signs of severe rash = face, lips, palms, feet, blistering, raised, fever, systemic signs, High eosinophils/LFTs. If rash was mild, can retitrate super slow in 1 month (start 5mg/d, raise by 5mg q2weeks to 25mg then use usual titration).
If patient has been off lamictal for > 7 days need to retitrate to avoid rash.
EMR Text
Bipolar and Cyclothymic
Lamotrigine use based on FDA approval for prevention in bipolar disorder, as well as controlled trials where it treated bipolar depression.
Risk of severe allergic rash reviewed with patient.
Treatment resistant depression
Lamotrigine use based on controlled trials in treatment resistant depression (Goh KK et al, J Psychopharmacol. 2019;33(6):700-713).
Risk of severe allergic rash reviewed with patient.
OCD
Lamotrigine use based on controlled trials in OCD (Bruno A et al, J Psychopharmacol. 2012;26(11):1456-1462).
Risk of severe allergic rash reviewed with patient.
Borderline
Lamotrigine use based on controlled trials in borderline personality disorder (Reich, 2009; Tritt, 2005).
Risk of severe allergic rash reviewed with patient.
Depersonalization
Lamotrigine use based on controlled and observational trials in depersonalization disorder (Aliyev NA, Aliyev ZN. J Clin Psychopharmacol. 2011;31(1):61-65).
Risk of severe allergic rash reviewed with patient.