MajorFluoroquinolone antibacterials×Oral hypoglycemic agents. Sulfonylureas
Updated · Methodology
Mechanism
Ciprofloxacin disrupts insulin secretion from pancreatic β-cells and concurrently inhibits CYP2C9 – the glibenclamide metabolic route. Glibenclamide plasma levels rise, intensifying its hypoglycaemic effect. FDA warning was issued in 2018.
Symptoms
Severe hypoglycaemia: sweating, tremor, hunger, tachycardia, confusion; severe cases progress to seizures and coma. Symptoms appear within 1–7 days, especially in older patients and chronic kidney disease.
Management
Avoid the combination. Alternative antibiotics: a cephalosporin or fosfomycin (no CYP2C9 effect and no β-cell impact). If ciprofloxacin is needed, monitor glucose 4 times daily and warn the patient about hypoglycaemia signs.
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Sources
- FDA: Cipro (ciprofloxacin hydrochloride) prescribing information (2016)– ; DailyMed setid 888dc7f9-ad9c-4c00-8d50-8ddfd9bd27c0
- AEMPS: Ficha técnica: Ciprofloxacino (nº registro 62765), sección 4.4 (2025)– AEMPS, CIMA, nº registro 62765, revisión 11/2025, sección 4.4