Moderate
Ciprofloxacin × Omeprazole
Fluoroquinolone antibacterials×Proton pump inhibitors
Mechanism
Ciprofloxacin absorbs better in acidic gastric environment. Omeprazole raises gastric pH — ciprofloxacin bioavailability drops by 20–30%. Clinically significant in infections with borderline pathogen sensitivity.
Symptoms
In severe infection: inadequate clinical response — persistent fever, symptoms, and inflammation markers 48–72 hours after antibiotic start.
Management
On the combination, take ciprofloxacin 2 hours before or 6 hours after omeprazole. If dosing cannot be separated, alternative antibiotics: amoxicillin-clavulanate for respiratory infections, a cephalosporin for UTIs. In urinary infections, ciprofloxacin still reaches adequate urine concentrations regardless of bioavailability.
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
- Lexicomp: Lexicomp Drug Interactions (2024)– Wolters Kluwer Clinical Drug Information, Inc. Lexi-Interact Online, 2024
- Pharmaceutical Press: Stockley's Drug Interactions, 12th edition (2024)– Preston CL (ed.). Stockley's Drug Interactions. 12th ed. London: Pharmaceutical Press; 2024