Amitriptyline and Carbamazepine: 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
Amitriptyline
Carbamazepine
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.
Here's what's going on. Carbamazepine (Tegretol) is a strong "enzyme booster" in your liver. It speeds up how fast your body breaks down amitriptyline (Elavil). That means less amitriptyline stays in your system, so your antidepressant may not work as well as it should.
In practice, that can look like your depression or nerve pain symptoms not improving, or coming back. The good news is this is very manageable. Your care team may check your amitriptyline levels and adjust your dose to make up for the difference. Please don't stop or change either medicine on your own. Just let your pharmacist or doctor know you take both so they can keep an eye on things.
Effect: Carbamazepine, a potent CYP3A4/hepatic microsomal inducer, enhances the metabolism of amitriptyline, reducing TCA exposure and potentially its efficacy. Neither drug is a prodrug, so the direction is straightforward: reduced parent (and active metabolite) levels.
- Magnitude: A retrospective pediatric study showed ~50% reduction in imipramine/desipramine levels with concomitant carbamazepine.
- Onset: Unspecified (induction typically develops over days to weeks).
- Evidence: Probable.
- Management: Monitor TCA plasma levels and clinical response; the amitriptyline dose may need upward adjustment, individualized to the patient. Reassess if carbamazepine is later discontinued (levels may rise).
What happens
Reduced tricyclic antidepressants exposure and reduced efficacy of tricyclic antidepressants
Interaction Deep Dive
Giving carBAMazepine together with TCAs can lower the exposure to TCAs. When these agents are used concurrently, monitor TCAs levels carefully and modify the dose as required12. By inducing hepatic enzymes, carBAMazepine likely increases the hepatic microsomal metabolism of imipramine and other tricyclic antidepressants7. A retrospective analysis involving 36 children who had hyperactivity related to attention deficit disorder found that levels of the antidepressant (imipramine along with its metabolite desipramine) fell by 50% in those taking carBAMazepine relative to the levels seen with imipramine given by itself3.
Why it happens (mechanism)
Unknown
How to manage this interaction
How your care team typically handles this:
- Keep taking both medications exactly as prescribed unless your prescriber tells you otherwise.
- Your team may check your amitriptyline blood levels and watch how well your symptoms are controlled.
- Because carbamazepine can lower amitriptyline levels, your amitriptyline dose may need to be adjusted and individualized by your care team.
- Remember that if carbamazepine is ever stopped, your amitriptyline levels could rise, so tell your team about any medication changes.
What to raise: Let your pharmacist or doctor know you take both, and report if your mood or pain symptoms seem to be slipping.
Management is individual — confirm any change with your pharmacist or prescriber.
Literature reports
5 reports — tap to read
a) A retrospective study of 36 children with attention deficit hyperactivity disorder found that the mean plasma concentration of imipramine was significantly reduced in patients who were also receiving carBAMazepine. Patients taking imipramine by itself had an average dose of 1.3 mg/kg, whereas patients receiving both imipramine and carBAMazepine had an average imipramine dose of 1.8 mg/kg. The plasma concentrations of imipramine, desipramine, and total tricyclic antidepressant were significantly lower in patients treated concurrently with carBAMazepine. It may be necessary to raise the imipramine dose when carBAMazepine is introduced into therapy, and to lower the imipramine dose if carBAMazepine is discontinued 3.
b) Concurrent use of carBAMazepine reduces the steady-state total serum concentrations of imipramine and the mean concentrations of desipramine. Thirteen patients received imipramine 2 mg/kg/day for 3 weeks, after which carBAMazepine 400 mg/day was added. The ratios of total imipramine concentrations to desipramine concentrations were comparable before and two weeks after carBAMazepine was taken (0.7 +/- 0.41 versus 0.63 +/- 0.36; p greater than 0.05). The free fractions of imipramine and desipramine increased following the addition of carBAMazepine. Even with reduced total concentrations of imipramine and desipramine, combining carBAMazepine treatment in depressed patients is effective and well tolerated. Increasing the imipramine dose does not seem to be required in the depressed patients enrolled in this study 4.
c) The simultaneous use of carBAMazepine and antidepressants has been reported to lower antidepressant concentrations 53.
d) A study assessed the impact of carBAMazepine on amitriptyline concentrations in 8 psychiatric inpatients who were given an average amitriptyline dose of 137.5 mg per day. Every patient received treatment for at least 7 days before baseline antidepressant concentrations were measured. CarBAMazepine was added at a mean dose of 593 mg and maintained over a 4 week period. Among patients on combination therapy, serum amitriptyline and nortriptyline concentrations were significantly reduced (42% and 40% respectively) compared with patients receiving amitriptyline alone, although the amitriptyline to nortriptyline ratio stayed relatively constant 5.
e) A single case was reported in which nortriptyline concentrations fell by more than half following the addition of carBAMazepine 6.
Common questions
Can I take Amitriptyline and Carbamazepine together?
Carbamazepine speeds up the breakdown of amitriptyline, which can weaken the antidepressant's effect. Keep taking both as prescribed and let your care team monitor levels and adjust your amitriptyline dose as needed. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Amitriptyline and Carbamazepine interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Amitriptyline and Carbamazepine interaction managed?
How your care team typically handles this: Keep taking both medications exactly as prescribed unless your prescriber tells you otherwise. Your team may check your amitriptyline blood levels and watch how well your symptoms are controlled. Because carbamazepine can lower amitriptyline levels, your amitriptyline dose may need to be adjusted and individualized by your care team. Remember that if carb… 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 Amitriptyline or Carbamazepine 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 a safer alternative to one of these medications for me?
References (7)
- Product Information: Tegretol(R)-XR oral extended-release tablets, carbamazepine oral extended-release tablets. Novartis Pharmaceuticals Corporation (per FDA), East Hanover, NJ, 2023. DailyMed
- Product Information: Tegretol(R) oral chewable tablets, oral tablets, oral suspension, carbamazepine oral chewable tablets, oral tablets, oral suspension. Novartis Pharmaceuticals Corporation (per FDA), East Hanover, NJ, 2023. DailyMed
- Brown CS, Wells BG, Cold JA, et al: Possible influence of carbamazepine on plasma imipramine concentrations in children with attention deficit hyperactivity disorder. J Clin Psychopharmacol 1990; 10:359-362. DOI
- Szymura-Oleksiak J, Wyska E, & Wasieczko A: Pharmacokinetic interaction between imipramine and carbamazepine in patients with major depression. Psychopharmacology 2001; 154:38-42. PubMed
- Leinonen E, Lillsunde P, Laukkanen V, et al: Effects of carbamazepine on serum antidepressant concentrations in psychiatric patients. J Clin Psychopharmacol 1991; 11:313-318. DOI
- Brosen K & Kragh-Sorensen P: Concomitant intake of nortriptyline and carbamazepine. Ther Drug Monit 1993; 15:258-260. PubMed
- Moody JP, Whyte SF, MacDonald AJ, et al: Pharmacokinetic aspects of protriptyline plasma levels. Eur J Clin Pharmacol 1977; 11:51-56. PubMed
Keep reading about Amitriptyline
Keep reading about Carbamazepine
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