Carbamazepine's own level rises with common antidepressants and antibiotics, and MAOIs must stop 14 days before
The Tegretol label lists fluoxetine, fluvoxamine, trazodone, cimetidine, omeprazole, ciprofloxacin, erythromycin and diltiazem among drugs that "increase plasma carbamazepine levels"; MAOIs stop 14 days before; nefazodone is barred.
Reasonable evidence with real limitations. how we score evidence
Caveat on this rating: The label's list mixes drugs "shown" and drugs "expected" to raise the level, without distinguishing which is which for each entry.
Carbamazepine is both a victim and a cause of interactions: other drugs change its level, and it lowers the level of many others by inducing their metabolism. This row is about the first half; the lamotrigine, clozapine and valproate rows carry the second.
Significant findings
TEGRETOL prescribing information (Novartis, August 2026), Contraindications: "on theoretical grounds its use with monoamine oxidase (MAO) inhibitors is not recommended. Before administration of Tegretol, MAO inhibitors should be discontinued for a minimum of 14 days, or longer if the clinical situation permits. Coadministration of carbamazepine and nefazodone may result in insufficient plasma concentrations of nefazodone and its active metabolite to achieve a therapeutic effect. Coadministration of carbamazepine with nefazodone is contraindicated."
Drug Interactions: "When carbamazepine is given with drugs that can increase or decrease carbamazepine levels, close monitoring of carbamazepine levels is indicated and dosage adjustment may be required." The drugs that raise it: "CYP3A4 inhibitors inhibit Tegretol metabolism and can thus increase plasma carbamazepine levels. Drugs that have been shown, or would be expected, to increase plasma carbamazepine levels include aprepitant, cimetidine, ciprofloxacin, danazol, diltiazem, macrolides (e.g., erythromycin, clarithromycin), fluoxetine, fluvoxamine, trazodone, omeprazole, oxybutynin" and others.
The fluvoxamine label in this wave confirms the pairing from the other side: "Elevated carbamazepine levels and symptoms of toxicity have been reported with the coadministration". The clozapine label lists carbamazepine as a CYP3A4 inducer whose withdrawal calls for a clozapine dose review.
Worth asking
Two of the level-raisers are antidepressants a psychiatrist might add to carbamazepine, fluoxetine and trazodone, and two are drugs anyone might be given for a week, an antibiotic and an acid reducer. If you take carbamazepine, the label's own instruction is the question to ask: is a level being checked after the new drug starts? Toxicity shows as dizziness, double vision, unsteadiness and drowsiness.
Source
TEGRETOL (carbamazepine) tablets, suspension and extended-release tablets: FDA-approved prescribing information, Contraindications and Drug Interactions — Novartis Pharmaceuticals Corporation; US Food and Drug Administration (2026)
Regulator or national health body
How this was scored
- Study design
- Regulatory safety determination
- Funding
- Industry funded
- Published in
- Regulator or national health body
- Sample size
- not recorded
- Preregistered
- not recorded
- Conflicts disclosed
- not recorded
- Independent of proponent
- not recorded
- Retracted
- No
Read the full scoring rubric, including what it can't tell you.
Published September 21, 2026.
Questions
How strong is the evidence behind this?
veisund rates this source "moderate evidence". Reasonable evidence with real limitations. It scores 57 out of 100 on our published rubric. One caveat travels with that badge: The label's list mixes drugs "shown" and drugs "expected" to raise the level, without distinguishing which is which for each entry. The score is calculated from recorded facts about the source — study design, funding, publication venue, sample size, preregistration — not typed in by an editor.
What is the source for this?
TEGRETOL (carbamazepine) tablets, suspension and extended-release tablets: FDA-approved prescribing information, Contraindications and Drug Interactions — Novartis Pharmaceuticals Corporation; US Food and Drug Administration (2026). Published in: Regulator or national health body. The full source is linked on this page so you can read it yourself.
Who paid for this research, and does that matter?
Study design: Regulatory safety determination. Funding: Industry funded. Independence from the proponent is not recorded. Industry sponsorship is one of the most reliably measured biases in medicine, which is why funding carries real weight in the score rather than sitting in a footnote.
Is this medical advice?
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.