What are the causes and symptoms of a urinary tract infection (UTI)?

From the Guidelines

Urinary tract infections (UTIs) should be treated with antibiotics, with first-line treatment including nitrofurantoin (Macrobid) 100mg twice daily for 5 days, trimethoprim-sulfamethoxazole (Bactrim) 160/800mg twice daily for 3 days, or fosfomycin (Monurol) 3g single dose, as recommended by the most recent guidelines 1. For uncomplicated UTIs, symptoms typically include painful urination, frequent urination, cloudy urine, strong-smelling urine, and pelvic pain. While waiting for antibiotics to work, patients should drink plenty of water to flush bacteria from their system, urinate frequently, and consider over-the-counter pain relievers like ibuprofen or acetaminophen for discomfort. Some key factors to consider in the management of UTIs include:

• Avoiding caffeine, alcohol, and spicy foods which can irritate the bladder
• UTIs occur when bacteria, usually E. coli from the digestive tract, enter the urethra and multiply in the bladder
• Women are more susceptible due to their shorter urethra
• If symptoms worsen, include fever or back pain, or don't improve within 48 hours of antibiotic treatment, patients should seek immediate medical attention as the infection may have spread to the kidneys The European Association of Urology guidelines on urological infections provide a comprehensive overview of the management of UTIs, including the use of antibiotics and the importance of addressing underlying complicating factors 1. In cases of complicated UTIs, the guidelines recommend appropriate management of the urological abnormality or underlying complicating factor, as well as optimal antimicrobial therapy based on the severity of the illness and local resistance patterns 1. Key points to consider in the management of complicated UTIs include:
• The microbial spectrum is greater than for uncomplicated UTIs, and antimicrobial resistance is more likely
• E. coli, Proteus spp., Klebsiella spp., Pseudomonas spp., Serratia spp., and Enterococcus spp. are the most common species found in cultures
• Treatment for 7-14 days is generally recommended, but the duration should be closely related to the treatment of the underlying abnormality.

From the Research

Urinary Tract Infection Treatment

• The recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females is a 5-day course of nitrofurantoin, a 3-g single dose of fosfomycin tromethamine, or a 5-day course of pivmecillinam 2.
• High rates of resistance for trimethoprim-sulfamethoxazole and ciprofloxacin preclude their use as empiric treatment of UTIs in several communities, particularly if patients who were recently exposed to them or in patients who are at risk of infections with extended-spectrum β-lactamases (ESBLs)-producing Enterobacteriales 2.
• Second-line options include oral cephalosporins such as cephalexin or cefixime, fluoroquinolones and β-lactams, such as amoxicillin-clavulanate 2.

Antibiotic Resistance and Treatment

• Current treatment options for UTIs due to AmpC- β -lactamase-producing Enterobacteriales include nitrofurantoin, fosfomycin, pivmecillinam, fluoroquinolones, cefepime, piperacillin-tazobactam and carbapenems 2.
• Treatment oral options for UTIs due to ESBLs-E coli include nitrofurantoin, fosfomycin, pivmecillinam, amoxicillin-clavulanate, finafloxacin, and sitafloxacin while pivmecillinam, fosfomycin, finafloxacin, and sitafloxacin are treatment oral options for ESBLs- Klebsiella pneumoniae 2.
• Parenteral treatment options for UTIs due to ESBLs-producing Enterobacteriales include piperacillin-tazobactam (for ESBL-E coli only), carbapenems including meropenem/vaborbactam, imipenem/cilastatin-relebactam, and sulopenem, ceftazidime-avibactam, ceftolozane-tazobactam, aminoglycosides including plazomicin, cefiderocol, fosfomycin, sitafloxacin, and finafloxacin 2.

Diagnosis and Treatment of Uncomplicated UTIs

• An acute uncomplicated urinary tract infection (UTI) is a bacterial infection of the lower urinary tract with no sign of systemic illness or pyelonephritis in a noncatheterized, nonpregnant adult with no urologic abnormalities or immunocompromise 3.
• In women, a self-diagnosis of a UTI with the presence of typical symptoms (e.g., frequency, urgency, dysuria/burning sensation, nocturia, suprapubic pain), without vaginal discharge, is accurate enough to diagnose an uncomplicated UTI without further testing 3.
• First-line antibiotics include nitrofurantoin for five days, fosfomycin in a single dose, trimethoprim for three days, or trimethoprim/sulfamethoxazole for three days 3.

Nitrofurantoin as a Treatment Option

• Nitrofurantoin (NF), a wide-spectrum antibiotic accessible since 1953, is utilized widely to treat urinary tract infections as it usually stays active against drug-resistant uropathogen 4.
• The use of Nitrofurantoin has increased exponentially since new guidelines have repositioned it as first-line therapy for uncomplicated lower urinary tract infection (UTI) 4.
• It can be concluded from this review that NF can be considered as the most effective drug in the treatment of acute urinary infection, but due to the long-term side effects of this drug, especially in elderly patients, it is essential to introduce some criteria for prescribing NF in cases of chronic UTI 4.

Historical Context of UTI Treatment

• Sulfonamides, trimethoprim-sulfamethoxazole, nitrofurantoin, and nalidixic acid are excreted in the urine in high concentration and, with the exception of Pseudomonas aeruginosa and Serratia marcescens, are all active in vitro against usual aerobic gram-negative bacteria 5.
• Trimethoprim-sulfamethoxazole is a very effective combination agent in vitro, has appealing pharmacokinetic properties, and is usually well tolerated by patients 5.

Current Prescribing Practices

• Uncomplicated urinary tract infections are one of the most common bacterial infections in the United States 6.
• Clinical practice guidelines from the Infectious Diseases Society of America recommend nitrofurantoin, trimethoprim-sulfamethoxazole, and Fosfomycin as first-line antibiotic treatments and discourage the use of fluoroquinolone antibiotic agents 6.
• The proportion of prescriptions for each antibiotic drug class were reported with 95% confidence intervals and compared with the Infectious Diseases Society of America guidelines 6.