CriticalSSRI (selective serotonin reuptake inhibitor)×Third-generation fluoroquinolone
Updated · Methodology
Mechanism
Levofloxacin is a fluoroquinolone, and its SmPC devotes a section to caution in patients already taking QT-prolonging drugs. The citalopram SmPC lists ongoing treatment with any drug capable of prolonging the QT interval among its contraindications, with no exceptions.
Symptoms
QTc prolongation on ECG, palpitations, dizziness, syncope. The end point is polymorphic ventricular tachycardia of the torsade type progressing to ventricular fibrillation. The risk is higher with hypokalaemia, hypomagnesaemia, bradycardia, decompensated heart failure and in women.
Management
The pair sits in the citalopram SmPC contraindications, so the question is which drug stays, not how far to cut the dose. The fluoroquinolone label says caution, the SSRI label says contraindication, and the stricter document sets the severity. For a community infection the antibiotic is picked outside this group.
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.
Summary of a multi-drug list →
Medicine list: everything you take in one place →
Sources
- FDA: Levofloxacin tablet (Chartwell Rx, LLC) – Prescribing Information – QT and CNS warnings (2020)– FDA Levaquin label, Warnings and Precautions §5.10; DailyMed setid 5c6c117c-9d91-48f4-9aaa-ee70b99218c2
- AEMPS: Ficha técnica de Seropram 30 mg (citalopram) (2024)– AEMPS CIMA, nregistro 63564, revisión 01/2024, secciones 4.2, 4.3 y 4.4
- AEMPS: Ficha técnica de Tavanic 500 mg (levofloxacino) (2026)– AEMPS CIMA, nregistro 62065, revisión 08/2026, secciones 4.4 y 4.5