What are risk factors for ciprofloxacin associated crystalline nephropathy?
While AIN is the most common cause of AKI with ciprofloxacin, crystalluria does occur. The drug is insoluble at alkaline pH.
Ciprofloxacin causes crystalluria when the urine pH is greater than 7.3, especially with higher drug doses. AKI develops within 2 days to 2 weeks of exposure and urinalysis reveals crystals, which are strongly birefringent and show a wide array of appearances, including needles, sheaves, stars, fans, butterflies, and other unusual shapes.
Needle-shaped birefringent crystals are seen within the tubules on biopsy. Ciprofloxacin crystalline nephropathy should be considered as a cause of AKI in elderly patients with impaired kidney function, volume depletion, and urine pH > 6.0. Prevention includes dose adjustment for GFR and volume repletion.
