Ciprofloxacin and Duloxetine interaction
Ciprofloxacin and Duloxetine: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Ciprofloxacin label · effective 2026-06-30
Duloxetine Avoid Use Five-fold increase in duloxetine exposure If unavoidable, monitor for duloxetine toxicity.
…syndrome, uncorrected electrolyte imbalance, such as hypokalemia or hypomagnesemia and cardiac disease, such as heart failure, myocardial infarction, or bradycardia), and patients receiving Class IA antiarrhythmic agents (quinidine, procainamide), or Class III antiarrhythmic agents (amiodarone, sotalol), tricyclic antidepressants, macrolides, and antipsychotics.
Drugs Known to Prolong QT Interval Avoid Use Ciprofloxacin may further prolong the QT interval in patients receiving drugs known to prolong the QT interval (for example, class IA or III antiarrhythmics, tricyclic antidepressants, macrolides, antipsychotics) [see Warnings and Precautions ( 5.12 ) and Use in Specific Populations ( 8.5 )].
From the Duloxetine label · effective 2026-03-02
Strong CYP1A2 inhibitors : Avoid concomitant use.
Strong CYP1A2 Inhibitors Prevention or Management Avoid concomitant use of Duloxetine Delayed-Release Capsules with strong CYP1A2 inhibitors [see Clinical Pharmacology ( 12.3 )].
CYP2D6 Poor Metabolizers Using Strong Inhibitor of CYP1A2 Prevention or Management Avoid co-administration of Duloxetine Delayed-Release Capsules and strong CYP1A2 inhibitors in patients who are CYP2D6 poor metabolizers [see Clinical Pharmacology ( 12.3 )] .
The risk of BP decreases may be greater in patients taking concomitant medications that induce orthostatic hypotension (such as antihypertensives) or are potent CYP1A2 inhibitors [see Drug Interactions ( 7.1 )] and in patients taking duloxetine delayed-release capsules at doses above 60 mg daily.
Mechanism and Clinical Effect(s) Concomitant use of Duloxetine Delayed-Release Capsules with CYP1A2 inhibitors increase the exposures of duloxetine.
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Open in the checkerNot 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.