Question explored with the scientific record
Conversation so far
- 1 Are massive lamotrigine side effects worth it
- 2 Are there better drugs for epilepsy than lamotrigine
- 3 Are there better drugs for adult epilepsy than lamotrigine
- 4 What are the side effects of lamotrigine
Answered on this page ↓
What are the side effects of lamotrigine
The short version: the rash is the side effect that matters, it is common, and it can occasionally become the life-threatening kind.
In adults adding lamotrigine to valproate, rash hit about 13 in 100, and about 14 in 100 without valproate, so the combination did not clearly raise it when started low [4]. Children on valproate were worse: 5 of 14 got a rash [4]. Most rashes are mild, but the serious form, Stevens-Johnson syndrome, is real. A 22-year-old on lamotrigine plus valproate developed it 17 days in, with blisters spreading from lip to mouth, vagina and trunk within a day [1]. A 34-year-old got the SJS/TEN overlap at 20% of body surface 12 days after starting 100 mg, with a predicted death risk of about 12 in 100 [2].
| Side effect | Rate in adults |
|---|---|
| Any adverse effect (monotherapy) | 18.6% [6] |
| Rash, added to valproate | 13% [4] |
| Rash, no valproate | 14.2% [4] |
| Stopped for rash | 6% [4] |
| Hospitalized for low sodium, new start | not significant [3] |
The milder stuff is common and dull: headache, nausea, dizziness, tremor, fatigue [5]. Low sodium was not a clear signal for lamotrigine, unlike carbamazepine and levetiracetam [3]. Weight gain was minimal, 0.4 kg [6].
These are small observational studies and case reports, not trials built to catch rare harm. The serious rash risk in the general adult population is not quantified here.
My call: the rash is the one to watch, especially in the first weeks and especially with valproate; most people get through it, a few do not. Confidence: moderate on rash frequency, low on the true rate of the dangerous form.
Sources used 6
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Stevens-Johnson syndrome due to Lamotrigine
A 22-year-old woman with epilepsy developed Stevens-Johnson syndrome 17 days after starting lamotrigine with valproate, and recovered after drug withdrawal, corticosteroids, and IVIG.
DOI: 10.17352/2455-8141.000027 -
Lamotrigine-induced Stevens-Johnson Syndrome Toxic Epidermal Necrolysis (SJS/TEN) overlap with transaminitis in an Asian female: a case report
A 34-year-old Asian woman with lamotrigine-associated SJS/TEN overlap (20% BSA) and transaminitis improved after drug withdrawal, systemic corticosteroids, and supportive care.
DOI: 10.15562/ism.v14i2.1660 -
Differences in associations of antiepileptic drugs and hospitalization due to hyponatremia: A population–based case–control study
A Swedish population-based case-control study linked nationwide registers to assess how initiation versus ongoing use of specific antiepileptic drugs (carbamazepine, oxcarbazepine, phenytoin, valproate, lamotrigine, levetiracetam, gabapentin) associates with hospitalization for …
DOI: 10.1016/j.seizure.2018.04.025 -
Adding Lamotrigine to Valproate: Incidence of Rash and Other Adverse Effects
Adding lamotrigine to valproate-containing regimens was associated with rash in 13% of patients, not significantly different from the 14.2% rate without valproate when lamotrigine was started at low doses.
DOI: 10.1111/j.1528-1157.1999.tb00831.x -
Effects of lamotrigine in patients with bipolar disorder and alcohol dependence
In an open-label 12-week trial, adjunctive lamotrigine was well tolerated and associated with reduced mood symptoms, alcohol craving, drinks per week and CDT in 28 outpatients with bipolar disorder and alcohol dependence.
DOI: 10.1111/j.1399-5618.2006.00292.x -
Adverse effects of carbamazepine, phenytoin, valproate and lamotrigine monotherapy in epileptic adult Chinese patients
This study evaluates the adverse effects of carbamazepine, phenytoin, valproate, and lamotrigine monotherapy in 505 adult Chinese patients with epilepsy, finding that while adverse effects were common, they were generally mild and did not lead to significant discontinuation of t…
DOI: 10.1016/j.clineuro.2009.12.014