Major
ciprofloxacin × sertraline
Fluoroquinolone antibacterials×Selective serotonin reuptake inhibitors (SSRIs)
Mechanism
Additive QT prolongation: sertraline modestly and ciprofloxacin modestly. In older patients with additional factors (hypokalemia, bradycardia, female sex), torsades de pointes risk increases. Ciprofloxacin also weakly inhibits CYP enzymes, potentially raising sertraline concentration slightly.
Management
Obtain a baseline ECG when prescribing ciprofloxacin to a patient on sertraline. Keep potassium above 4.0 mmol/L. If QTc exceeds 500 ms, switch to a non-fluoroquinolone antibiotic.
Sources
- FDA: FDA Drug Safety Communication: FDA updates warnings for oral and injectable fluoroquinolone antibiotics due to disabling side effects (2016)— FDA Drug Safety Communication, July 26, 2016
- Lexicomp: Lexicomp Drug Interactions (2024)— Wolters Kluwer Clinical Drug Information, Inc. Lexi-Interact Online, 2024