Citalopram has a dose ceiling because of the heart, and it drops to 20 mg with certain other drugs
The Celexa label caps the dose at 40 mg a day for QT prolongation, and at 20 mg over age 60, with liver impairment, for CYP2C19 poor metabolizers or with a CYP2C19 inhibitor. Pimozide is contraindicated; other QT drugs avoided.
Reasonable evidence with real limitations. how we score evidence
Caveat on this rating: The 2011 notice was criticised in the literature for resting on QT interval data rather than on measured arrhythmias; the label itself reports postmarketing cases, which are unquantified. The Beach 2013 review in this wave notes there are no well-controlled studies of torsades risk with psychiatric drugs.
Citalopram is one of the most prescribed antidepressants, and the only SSRI whose label sets a hard maximum dose because of the heart. Several of the interactions here are about that ceiling.
Significant findings
CELEXA prescribing information (Allergan, August 2026), section 5.2: "CELEXA causes dose-dependent QTc prolongation an ECG abnormality that has been associated with Torsade de Pointes (TdP), ventricular tachycardia, and sudden death, all of which have been observed in postmarketing reports for citalopram. Because of the risk of QTc prolongation at higher CELEXA doses, it is recommended that CELEXA not be given at doses above 40 mg once daily."
Section 2.3: "The maximum recommended dosage of CELEXA for patients who are greater than 60 years of age, patients with hepatic impairment, and for CYP2C19 poor metabolizers is 20 mg once daily." Section 2.4: "The maximum recommended dosage of CELEXA when used concomitantly with a CYP2C19 inhibitor is 20 mg once daily."
On stacking QT drugs: "CELEXA should also be avoided in patients who are taking other drugs that prolong the QTc interval. Such drugs include Class 1A (e.g., quinidine, procainamide) or Class III (e.g., amiodarone, sotalol) antiarrhythmic medications, antipsychotic medications (e.g., chlorpromazine, thioridazine), antibiotics (e.g., gatifloxacin, moxifloxacin)". Pimozide is contraindicated outright: coadministration "increases plasma concentrations of pimozide, a drug with a narrow therapeutic index, and may increase the risk of QT prolongation and/or ventricular arrhythmias."
Section 5.3 names the serotonin syndrome partners: "The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, meperidine, methadone, tryptophan, buspirone, amphetamines, and St. John's Wort) and with drugs that impair metabolism of serotonin, i.e., MAOIs". Symptoms of serotonin syndrome "were noted in 0.1% of MDD patients treated with CELEXA in premarketing clinical trials." MAOIs need a 14-day gap in either direction.
Worth asking
Two questions if you take citalopram. Which CYP2C19 inhibitors are on your list (the label names the mechanism; common ones include some acid reducers), and does your dose respect the 20 mg ceiling if so? And is any other drug you take on the QT list, including antipsychotics and some antibiotics? A pharmacist can answer both in a minute. The Beach 2013 row in this wave is the review of QT risk across psychiatric drugs.
Source
CELEXA (citalopram) tablets: FDA-approved prescribing information, Dosage 2.3 to 2.5, Contraindications 4, Warnings and Precautions 5.2 and 5.3, Drug Interactions 7 — Allergan, Inc.; 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 2011 notice was criticised in the literature for resting on QT interval data rather than on measured arrhythmias; the label itself reports postmarketing cases, which are unquantified. The Beach 2013 review in this wave notes there are no well-controlled studies of torsades risk with psychiatric drugs. 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?
CELEXA (citalopram) tablets: FDA-approved prescribing information, Dosage 2.3 to 2.5, Contraindications 4, Warnings and Precautions 5.2 and 5.3, Drug Interactions 7 — Allergan, Inc.; 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.