A nurse is providing discharge education to a client starting a fluoroquinolone for an infection. Which adverse effect should the nurse include in the teaching?

A. Ototoxicity: Fluoroquinolones are not associated with damage to the auditory nerve or inner ear structures. Hearing loss or tinnitus is not a recognized adverse effect of this antibiotic class. B. Crystalluria: Fluoroquinolones are well-absorbed and excreted renally, but they rarely precipitate crystals in the urine. Hydration is advised, but crystalluria is not a common concern. C. Tendon rupture: Fluoroquinolones can weaken collagen and connective tissue, increasing the risk of tendonitis and tendon rupture, particularly in older adults and those taking corticosteroids. Achilles tendon rupture is the most frequently reported, making this a critical point for patient education. D. GI bleed: Gastrointestinal bleeding is not a typical adverse effect of fluoroquinolones. While GI upset such as nausea or diarrhea may occur, serious bleeding is not commonly associated with this drug class.