Lamotrigine (US brand name Lamictal®, Lamictal CD®, Lamictal ODT® and generic) is an anticonvulsant that is used in the treatment of bipolar I disorder.
On this page, we will provide basic information about this medication. Links to other articles on this website with more advanced information and tips related to this medication and related topics are provided below—under Related Pages below.
FDA-approved indications
Maintenance treatment of bipolar I disorder to delay the time to occurrence of mood episodes in patients treated for acute mood episodes with standard therapy
Mechanism of Action/ Pharmacodynamics
The Prescribing Information notes that, “The mechanisms by which lamotrigine exerts its therapeutic action in bipolar disorder have not been established.”
What we do know is that lamotrigine inhibits voltage-sensitive sodium channels, which stabilizes neuronal membranes. This, in turn, modulates the release of excitatory amino acids like glutamate and aspartate from presynaptic neurons.
Dosage
1. Dosing regimen in adult patients with bipolar disorder
a. In patients not taking carbamazepine, phenytoin, phenobarbital, primidone, or valproate
Weeks 1 and 2: 25 mg daily
Weeks 3 and 4: 50 mg daily
Week 5: 100 mg daily
Week 6: 200 mg daily
Week 7: 200 mg daily
b. In patients taking valproate
Weeks 1 and 2: 25 mg every other day
Weeks 3 and 4: 25 mg daily
Week 5: 50 mg daily
Week 6: 100 mg daily
Week 7: 100 mg daily
c. In patients taking carbamazepine, phenytoin, phenobarbital, or primidone and not taking valproate
Weeks 1 and 2: 50 mg daily
Weeks 3 and 4: 100 mg daily, in divided doses
Week 5: 200 mg daily, in divided doses
Week 6: 300 mg daily, in divided doses
Week 7: up to 400 mg daily, in divided doses
2. Dosage adjustments to lamotrigine in adults with bipolar disorder following discontinuation of psychotropic medications
a. Discontinuation of psychotropic drugs (excluding valproate, carbamazepine, phenytoin, phenobarbital, or primidone)
Week 1: Maintain the current dose of lamotrigine
Week 2: Maintain the current dose of lamotrigine
Week 3 onward: Maintain the current dose of lamotrigine
b. After discontinuation of valproate (current dose of lamotrigine 100 mg/day)
Week 1: 150 mg/day
Week 2: 200 mg/day
Week 3 onward: 200 mg/day
c. After discontinuation of carbamazepine, phenytoin, phenobarbital, or primidone (current dose of lamotrigine 400 mg/day)
Week 1: 400 mg/day
Week 2: 300 mg/day
Week 3 onward: 200 mg/day
Important information to remember
1. Treatment of acute manic or mixed episodes is not recommended with lamotrigine.
2. To reduce the risk of life-threatening rash, do not: administer with valproate, exceed the recommended initial dose, or exceed the recommended dose escalation.
3. Valproate increases lamotrigine concentrations more than 2-fold. Carbamazepine, phenytoin, phenobarbital, primidone, and rifampin decrease lamotrigine concentrations by approximately 40%. Estrogen-containing oral contraceptives decrease lamotrigine concentrations by approximately 50%. Protease inhibitors lopinavir/ritonavir and atazanavir/lopinavir decrease lamotrigine exposure by approximately 50% and 32%, respectively.
4. Dosage adjustment may be needed in moderate and severe hepatic impairment.
5. Reduced maintenance doses of lamotrigine may be needed in significant renal impairment.
Elderly: There is no clear research data, but the official Prescribing Information does urge a bit of caution: “Clinical studies of LAMICTAL for epilepsy and in Bipolar Disorder did not include sufficient numbers of subjects 65 years of age and over to determine whether they respond differently from younger subjects or exhibit a different safety profile than that of younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. “
Dosage forms and strengths
Scored tablets (Lamictal® and generic): 25 mg, 100 mg, 150 mg, and 200 mg.
Chewable dispersible tablets (Lamictal CD® and generic): 2 mg, 5 mg, and 25 mg.
Orally disintegrating tablets (Lamictal ODT® and generic): 25 mg, 50 mg, 100 mg, and 200 mg.
Important! Prescribing clinicians must refer to the full Prescribing Information (see link below) for a complete discussion of dosage, administration, warnings and precautions, contraindications, etc.
Related Pages
Lamotrigine (Lamictal®): Basic Information
Can lamotrigine monotherapy be used for maintenance treatment in bipolar I disorder?
Lamotrigine: No additional benefit at 400 mg per day?
Why don’t we routinely prescribe lamotrigine extended-release (Lamictal XR®)?
How to add valproate to lamotrigine
Tips on using lamotrigine for mood disorders: Interview with Dr. Nassir Ghaemi
Starting lamotrigine
How to start and titrate lamotrigine (Lamictal®)
Dermatological precautions when starting lamotrigine
Restarting lamotrigine
Restarting lamotrigine
If lamotrigine is missed for a few days
Restarting lamotrigine: how many days?
Restarting lamotrigine: A case study
Lamotrigine and skin rash
Dermatological precautions when starting lamotrigine
Is it a benign or dangerous skin rash?
How common are benign and serious rashes with lamotrigine?
Lamotrigine rechallenge after a skin rash?
Lamotrigine side effects (other than skin rash)
Can lamotrigine levels predict adverse effects?
What to do about the risk of arrhythmias with lamotrigine
Can lamotrigine cause psychiatric side effects?
Can lamotrigine cause bruising?
Is the use of lamotrigine during pregnancy safe?
Oral sores in a patient on lamotrigine
Drug interactions with lamotrigine
5 Action Items about OCs and lamotrigine
Does lamotrigine decrease the effectiveness of oral contraceptives?
How to reduce lamotrigine when an inducer is stopped
Folic acid may counteract the benefit of lamotrigine
References
Prescribing Information: Lamotrigine (Lamictal®)
Lamotrigine: Patient information on Medlineplus.gov
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Have you encountered clients stating that lamotrigine (Lamictal) is making their depression worse? I have had quite a few clients tell me this and it has been difficult to parse out if it is their condition worsening or an adverse effect. Some anticonvulsants such as levetiracetam (Keppra) have been known to worsen depression, so it might not be such a wild phenomenon. Thoughts?
Thanks for your question! It has now been answered at the following link: https://simpleandpractical.com/lamotrigine-psychiatric-side-effects/
The textbook “Synopsis of Psychiatry” mentions other indications of lamotrigine such as borderline personality disorder and also in pain syndromes. How far has it has been found to be useful for the same, especially Borderline PD?
Also the book says it is not recommended below 16years. Do we strictly follow such cut-offs in guidelines while using lamotrigine?