Introduction
Urinary tract infections (UTIs) are among the commonest reasons for antibiotic use. Management depends on whether the infection is uncomplicated or complicated, lower or upper, and on local E. coli resistance.
Classification
- Uncomplicated: cystitis in a non-pregnant woman with a normal urinary tract.
- Complicated: men, pregnancy, obstruction, stones, catheter, incomplete emptying (prostatic hypertrophy, neurogenic bladder), diabetes, immunosuppression, kidney disease; SGLT2 inhibitors increase genital and urinary infections.
- Recurrent: ≥ 2 episodes in 6 months or ≥ 3 in 12 months.
- Pyelonephritis (upper UTI): fever, loin pain, systemic illness.
Pathogens
E. coli (70–80%), Proteus, Klebsiella, Enterococcus, Staphylococcus saprophyticus (young women); Pseudomonas and resistant Gram-negatives in complicated and hospital infections.
Uncomplicated cystitis
Urine culture is not needed for typical cystitis in young women, but is needed in men, pregnancy, recurrence, treatment failure and complicated UTI.
Complicated UTI and pyelonephritis
- Culture before treatment; 7–14 days.
- Mild pyelonephritis: oral ciprofloxacin 500 mg twice daily or levofloxacin 750 mg once daily for 5–7 days (where resistance < 10%); co-trimoxazole if the organism is sensitive.
- Severe: IV ceftriaxone, piperacillin–tazobactam, or an aminoglycoside; carbapenem for ESBL-producers.
- Multidrug-resistant Gram-negatives: newer agents such as ceftolozane–tazobactam or ceftazidime–avibactam.
- Treat the cause (catheter change, relieve obstruction).