Lamotrigine and Sertraline: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Lamotrigine
Sertraline
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
Let's talk about taking lamotrigine (Lamictal) and sertraline together. Your body clears lamotrigine through a process called glucuronidation. Sertraline may slow that process down a bit, which can let lamotrigine build up in your blood. When that happens, some people feel extra tired, foggy, sleepy, or a little confused.
This isn't common, and it doesn't mean these two can't be used together. Many people take them safely. The good news is your care team can stay ahead of it by checking your lamotrigine levels and fine-tuning your dose if needed. Please don't stop or change either medicine on your own. Just let your pharmacist or doctor know how you're feeling.
Effect: Increased lamotrigine exposure with risk of toxicity (fatigue, sedation, confusion, decreased cognition).
Mechanism: Sertraline is thought to competitively inhibit UGT-mediated glucuronidation, lamotrigine's primary clearance pathway, reducing its metabolism. Neither agent's efficacy depends on active metabolite formation here, so this is a straightforward PK-based increase in lamotrigine levels.
- Direction: Increased lamotrigine effect/exposure
- Onset: Delayed
- Evidence: Probable (two epilepsy case reports)
- Severity: Moderate
Management: Monitor lamotrigine plasma levels and titrate dose accordingly. Watch for CNS depressant/toxicity signs after sertraline initiation or dose changes.
What happens
An increased risk of lamotrigine toxicity (fatigue, sedation, confusion, decreased cognition)
Interaction Deep Dive
Lamotrigine toxicity following the start of sertraline treatment has been documented in two patients with epilepsy through case reports. The metabolism of lamotrigine occurs mainly by glucuronidation, whereas sertraline is processed via N-demethylation, hydroxylation, oxidative deamination, and glucuronidation. The proposed mechanism is that sertraline reduces the metabolism of lamotrigine by competitively inhibiting glucuronidation1.
Why it happens (mechanism)
Inhibition of lamotrigine glucuronidation
How to manage this interaction
Here is how a care team usually handles this combination:
- Keep taking both as prescribed unless your prescriber tells you otherwise.
- Your team may check your lamotrigine blood levels and adjust the dose so it stays individualized to you, especially after starting sertraline or changing its dose.
- Expect closer monitoring for signs like unusual tiredness, drowsiness, confusion, or trouble thinking.
Let your pharmacist or doctor know if you notice these symptoms after starting sertraline. Because the effect can appear gradually, mention any new fatigue or mental fog even weeks in.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
2 reports — tap to read
a) A 39-year-old woman with epilepsy was stabilized on lamotrigine 200 mg daily, with a starting lamotrigine blood concentration of 2.5 mcg/mL (9.8 mcmol/L). Owing to an intermittent explosive disorder, sertraline 25 mg daily was started. Six weeks afterward, the lamotrigine concentration had risen to 5.1 mcg/mL (20 mcmol/L), and the patient reported confusion and cognitive impairment. Sertraline was raised to 50 mg daily and lamotrigine was reduced to 100 mg daily. This reduced lamotrigine dose resolved the patient's confusion and cognitive impairment, and the lamotrigine blood level settled at 3.1 mcg/mL (12.1 mcmol/L) 1.
b) In a 17-year-old female patient with mixed epileptic disorder and explosivity, lamotrigine 450 mg daily was failing to control seizures. Sertraline was begun and titrated up to 75 mg daily with no adverse effects. Lamotrigine was likewise raised to 600 mg daily, and six weeks later the patient reported sedation, fatigue, and reduced cognition. At that point the lamotrigine blood level was 19.3 mcg/mL (75.4 mcmol/L). The sertraline dose was lowered to 50 mg daily while lamotrigine was raised to 800 mg daily, yielding a new steady-state lamotrigine level of 9.8 mcg/mL (38.3 mcmol/L). In this case report, the lamotrigine blood level fell to roughly 50% following a 33% reduction in the daily sertraline dose, despite the lamotrigine dose having been increased by 33% 1.
Common questions
Can I take Lamotrigine and Sertraline together?
Adding sertraline can raise lamotrigine levels and cause tiredness, sedation, or confusion; keep taking both as prescribed and ask your care team about monitoring lamotrigine levels and adjusting the dose. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Lamotrigine and Sertraline interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How is the Lamotrigine and Sertraline interaction managed?
Here is how a care team usually handles this combination: Keep taking both as prescribed unless your prescriber tells you otherwise. Your team may check your lamotrigine blood levels and adjust the dose so it stays individualized to you, especially after starting sertraline or changing its dose. Expect closer monitoring for signs like unusual tiredness, drowsiness, confusion, or trouble thinking.… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Lamotrigine or Sertraline need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (1)
- Kaufman KR & Gerner R: Lamotrigine toxicity secondary to sertraline. Seizure 1998; 7:163-165. DOI
Keep reading about Lamotrigine
Keep reading about Sertraline
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist