ModerateFluoroquinolone antibacterials×Biguanides. Oral antihyperglycemic agents
Updated · Methodology
Mechanism
Fluoroquinolones disturb glucose homeostasis — they can cause both hypoglycaemia (especially in older patients on glucose-lowering therapy) and hyperglycaemia. The mechanism involves pancreatic beta-cell effects.
Symptoms
Hypoglycaemia: sweating, tremor, hunger, confusion at glucose below 3.9 mmol/L. Hyperglycaemia: thirst, polyuria, fatigue.
Management
For short ciprofloxacin courses (5–7 days) on metformin, intensify glucose self-monitoring (twice daily) for the first week. In older patients and diabetics on insulin or sulfonylureas, choose an alternative antibiotic (cephalosporin, amoxicillin-clavulanate).
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
- Lexicomp: Lexicomp Drug Interactions (2024)– Wolters Kluwer Clinical Drug Information, Inc. Lexi-Interact Online, 2024
- AEMPS: Ficha técnica: Ciprofloxacino (nº registro 62765), sección 4.4 (2025)– AEMPS, CIMA, nº registro 62765, revisión 11/2025, sección 4.4