Lamotrigine: What It Treats and What to Watch For

Lamotrigine (brand name Lamictal) is a common medicine for seizures and for preventing mood episodes in bipolar disorder. It can work very well—especially at preventing bipolar depression and reducing some types of seizures—but it needs careful starting and monitoring. The most important thing to know early on is the risk of a serious skin rash. Spot a rash fast and call your prescriber.

How lamotrigine is used

Doctors prescribe lamotrigine mainly for two reasons: as an anticonvulsant for epilepsy and as a maintenance drug for bipolar disorder (to lower the chance of depressive episodes). It’s not usually the first choice for sudden manic symptoms—think of it as a steadying drug you take long-term.

Typical adult titration many prescribers use is: 25 mg once daily for 2 weeks, then 50 mg once daily for 2 weeks, then 100 mg once daily for 1 week, then increase to a common maintenance dose around 200 mg daily. That plan changes if you take other meds: valproate raises lamotrigine levels so doses must be much lower; enzyme-inducing drugs like carbamazepine or phenytoin lower lamotrigine levels and may need higher doses. Your doctor will tailor the schedule.

Key safety tips and interactions

Watch for early warning signs. Common side effects include dizziness, headache, nausea, blurred vision, and sleepiness. The urgent problem is any new rash—especially in the first 2–8 weeks. A rash can be harmless, but it can also be the start of Stevens-Johnson syndrome or toxic epidermal necrolysis. Stop the medicine and contact your clinician immediately if a rash, mouth sores, or unexplained fever appears.

Important drug interactions: valproate (divalproex) increases lamotrigine levels—doctors usually cut the lamotrigine dose. Carbamazepine, phenytoin, and phenobarbital speed up lamotrigine clearance and often require higher doses. Hormonal contraceptives containing estrogen can reduce lamotrigine levels; levels often fall during combined oral contraceptive use and rise again after stopping the pill, so dose adjustments may be needed. If you’re pregnant, lamotrigine levels commonly drop and doctors often raise the dose, then lower it again after birth.

Do not stop lamotrigine suddenly—abrupt withdrawal can trigger seizures or mood instability. If you need to stop, your clinician will taper the dose slowly.

Monitoring: blood levels aren’t required for everyone but are helpful when pregnancy, drug interactions, or unexpected side effects occur. Regular follow-ups matter: they let your prescriber catch a rash early, check how well the drug is working, and adjust doses safely.

Buying meds: only use a licensed pharmacy and always keep a valid prescription. Counterfeit or substandard meds are a real risk with shady online sellers.

If you have questions about lamotrigine and how it fits your health needs, bring them up with your prescriber—especially if you’re pregnant, planning pregnancy, on other seizure meds, or using hormonal birth control. That short conversation can make treatment safer and more effective.