Citalopram and Dofetilide interaction

Citalopram and Dofetilide: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.

Major

Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.

What the FDA labels say

From the Dofetilide label · effective 2026-04-24

Major

Use with Drugs that Prolong QT Interval and Antiarrhythmic Agents The use of dofetilide in conjunction with other drugs that prolong the QT interval has not been studied and is not recommended.

Warningsby drug classView label on DailyMed
Moderate

Inhibitors of this isoenzyme (e.g., macrolide antibiotics, azole antifungal agents, protease inhibitors, serotonin reuptake inhibitors, amiodarone, cannabinoids, diltiazem, grapefruit juice, nefazadone, norfloxacin, quinine, zafirlukast) should be cautiously co-administered with dofetilide as they can potentially increase dofetilide levels.

Drug interactionsby drug classView label on DailyMed
Minor

Such drugs include phenothiazines, cisapride, bepridil, tricyclic antidepressants, certain oral macrolides, and certain fluoroquinolones.

Warningsby drug classView label on DailyMed
No interaction

…(alone or in combinations such as with triamterene) (see CONTRAINDICATIONS ), other cardiovascular drugs (especially verapamil – see CONTRAINDICATIONS ), phenothiazines, and tricyclic antidepressants (see WARNINGS ).If a patient is taking dofetilide and requires anti-ulcer therapy, omeprazole, ranitidine, or antacids (aluminum and magnesium hydroxides) should be…

Precautionsby drug classView label on DailyMed

From the Citalopram label · effective 2025-10-07

Moderate

Avoid use of Citalopram Capsules in patients with congenital long QT syndrome, bradycardia, hypokalemia or hypomagnesemia, recent acute myocardial infarction, or uncompensated heart failure and patients taking other drugs that prolong the QTc interval.

Warnings and precautionsby drug classView label on DailyMed
Moderate

Citalopram should also not be used in patients who are taking other drugs that prolong the QTc interval [see Drug Interactions (7)].

Warnings and precautionsby drug classView label on DailyMed
Moderate

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), or any other class of medications known to prolong the QTc interval (e.g., pentamidine, levomethadyl acetate, methadone).

Warnings and precautionsby drug classView label on DailyMed
Moderate

These include those patients with the cardiac conditions noted above, and those taking other drugs that may prolong the QTc interval.

Warnings and precautionsby drug classView label on DailyMed

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Not medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.