Apixaban × Ciprofloxacin

Ciprofloxacin weakly affects CYP3A4 and P-glycoprotein — the main clearance routes of apixaban. It also suppresses vitamin K-producing gut flora. Additive bleeding risk.

Gum bleeding, epistaxis, bruising without trauma, black or tarry stools, haematuria. Higher risk in older patients, prior peptic ulcer disease, and chronic kidney disease.

For short ciprofloxacin courses (5–7 days), do not change the apixaban dose but monitor for bleeding signs. In patients over 75 or with creatinine clearance below 50 mL/min, choose an alternative antibiotic without P-glycoprotein effect — ceftriaxone, cefixime, amoxicillin-clavulanate.