Major
citalopram × Moxifloxacin
SSRI (selective serotonin reuptake inhibitor)×Fourth-generation fluoroquinolone
Mechanism
Both prolong QT (moxifloxacin 10-20 ms, citalopram dose-dependent). FDA in 2011 capped citalopram at 20 mg/day in elderly due to QT.
Symptoms
QTc above 500 ms, syncope, torsades de pointes risk.
Management
Prefer levofloxacin (less QT) or non-quinolone. ECG monitoring if combo needed.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
Sources
- FDA: Avelox (moxifloxacin) prescribing information – QT prolongation warning (2016)– FDA Avelox label, Warnings and Precautions §5.7 – avoid with QT-prolonging drugs
- FDA: FDA Drug Safety Communication on citalopram QT prolongation (2012)