Ciprofloxacin-induced drug fever.

Drug-induced fever is an uncommon but important differential in patients with unexplained fever. We present a case of a woman in her 60s with advanced renal disease and recent total hip arthroplasty who developed fever after an extended course of ciprofloxacin treatment. Extensive investigations, including cultures, imaging and orthopaedic review, failed to identify an infectious source. Although her fever initially resolved by day 2, it recurred on day 19 of treatment. Repeat assessments remained inconclusive. Ciprofloxacin-induced drug fever was suspected, and defervescence occurred within 48 hours of discontinuation, with no recurrence thereafter. This case highlights the importance of considering drug fever once other causes have been excluded. Early recognition can prevent unnecessary antibiotic escalation, reduce hospital stay and improve patient outcomes. Clinicians should maintain a high index of suspicion for this diagnosis, particularly when new medications coincide with unexplained fever in the absence of clear infection.