No, do not increase lamotrigine during an active manic episode—lamotrigine is not effective for acute mania and may worsen the episode.
Lamotrigine lacks antimanic efficacy and is approved only for maintenance therapy to prevent mood episodes, not for treating acute mania 1. During an active manic episode, you need to initiate or optimize an agent with proven antimanic properties.
Why Lamotrigine Should Not Be Increased During Mania
Lamotrigine has not demonstrated efficacy in treating acute mania 2, 3. The evidence consistently shows that lamotrigine's benefit lies in preventing depressive episodes and, to a lesser extent, delaying manic episodes—but it does not treat active mania 4. In fact, there are documented cases of lamotrigine inducing manic episodes, particularly in vulnerable populations 5, 6.
The mechanism explains this limitation: lamotrigine's antidepressant properties (through decreased glutamate release and sodium channel inhibition) may actually destabilize mood during an active manic phase 5.
What You Should Do Instead
For acute mania, standard therapy includes lithium, valproate, and/or atypical antipsychotic agents 1. These are the evidence-based first-line treatments:
Immediate Management Options:
- Lithium (approved for acute mania, including in adolescents ≥12 years) 1
- Valproate (approved for acute mania in adults) 1
- Atypical antipsychotics: aripiprazole, olanzapine, risperidone, quetiapine, or ziprasidone (all approved for acute mania) 1, 7
Regarding the Current Lamotrigine:
- Consider discontinuing or holding lamotrigine during the acute manic episode, especially if the patient has risk factors for lamotrigine-induced mania (bipolar I, manic predominant polarity, history of antidepressant-induced switches) 5
- At minimum, do not increase the dose
- Once the manic episode is controlled with appropriate antimanic agents, lamotrigine can be reintroduced for maintenance therapy to prevent future depressive episodes
Critical Pitfalls to Avoid
Do not confuse maintenance therapy with acute treatment. Lamotrigine's FDA approval and evidence base are for maintenance—preventing future episodes, particularly depression 1. The WHO guidelines similarly recommend lithium or valproate for acute mania, with lamotrigine reserved for maintenance after stabilization 7.
Beware of lamotrigine-induced manic switches. Recent evidence suggests this risk may be underestimated, particularly in patients with bipolar I disorder, manic predominant polarity, or those with an index manic episode 5. The 2022 case series documented rapid onset of severe mania (YMRS 31-35) within 1-3 weeks of lamotrigine initiation, with quick resolution upon discontinuation 5.
Once Mania is Controlled
After achieving stability with an antimanic agent for at least 2 weeks to several months 7, 1, you can consider reintroducing lamotrigine at 25 mg daily with slow titration (increasing by 25 mg every 1-2 weeks) to reach a maintenance dose of 200 mg/day over 6 weeks 8, 3. This slow titration minimizes rash risk and allows monitoring for mood destabilization. If the patient is on valproate, the target dose should be reduced to 100 mg/day 8.