Drug-induced Crystalluria in Sulfamethoxazole, High Dose Ciprofloxacin and High Dose Amoxicillin

Inclusion Criteria: * Age ≥ 18 years * Able to give informed consent without the intervention of a legal representative * Treatment with * sulfamethoxazole/trimethoprim, with minimum dose of * ≥ 800/160 mg q12h oral administration (PO) or intravenous administration (IV) for eGFR ≥ 30 ml/min * ≥ 400/80 mg q12h OR or IV for eGFR \< 30 ml/min OR * high dose ciprofloxacin, defined as * ≥ 750 mg q12h PO or ≥ 400 mg q8h IV for eGFR ≥ 60 ml/min * ≥ 750 mg q24h PO or ≥ 400 mg q12h IV for eGFR 15-59 m/min * ≥ 750 mg q24h PO OR ≥ 400 mg q24h IV for eGFR \< 15 ml/min OR * high dose amoxicillin, defined as * ≥ 2g q6h IV for eGFR ≥ 30 ml/min * ≥ 2g q8h IV for eGFR 15-29 ml/min * ≥ 2g q12h IV for eGFR \< 15 ml/min * Treatment for min 24 hours and sufficiently long to perform one crystalluria investigation as defined in the protocol * Baseline renal function up to 72 hours prior to the start of antibiotic treatment available (evaluated by serum creatinine and eGFR (CKD-EPI)) for all study groups and additional serum urea for the sulfamethoxazole group). Exclusion Criteria: * Unable to give informed consent without the intervention of a legal representative * No baseline renal function up to 72 hours prior to the start of antibiotic treatment available, evaluated by serum creatinine and eGFR (CKD-EPI)) for all study groups and additional serum urea for the sulfamethoxazole group. * Treatment duration \< 24 hours or insufficiently long to perform one crystalluria inves-tigation as defined in the protocol * Patients treated with hemodialysis or peritoneal dialysis, anuric patients before start of antibiotic treatment * Patients with urinary diversions