Ciprofloxacin

The combination of ciprofloxacin and amiodarone is specifically flagged as dangerous. Ciprofloxacin prolongs the cardiac QT interval and can precipitate life-threatening ventricular arrhythmias in patients with electrolyte abnormalities or concurrent QT-prolonging medications. Ciprofloxacin degrades collagen structure and tissue elasticity, with Achilles tendon rupture being the most commonly observed manifestation. Ciprofloxacin disrupts the normal gut microbiome and increases the risk of C. diff infection, a severe and potentially fatal colitis. Urine culture sensitivities should always guide antibiotic selection rather than defaulting to ciprofloxacin empirically.