A urinary tract infection (UTI) occurs when there is bacteria present in urinary tract. It is classified by the site of infection, lower tract and upper tract infection. Lower tract infections include cystitis (bladder), urethritis (urethra), and prostatitis (prostate gland). Upper tract infections involve the kidneys; these infections are classified as pyelonephritis. Uncomplicated UTIs usually involve the bladder and urethra, while complicated UTIs involve the prostate gland and the kidneys. Symptoms of a UTI include pain upon urination, increased urgency and frequency of urination, and heaviness in the bladder. Complicated UTIs may cause pain in the lower back, fever, nausea, and vomiting. UTIs are treated with antibiotics, which are chosen based on the type of organism and type of infection.
Bactrim
Bactrim, the brand name for trimethoprim-sulfamethoxazole, is a prescription medication available in tablet form. It is highly effective against most bacteria causing urinary tract infections and is the preferred therapy. High levels are achieved in the urinary tract making it extremely useful in preventing recurrent infections.
Penicillins
Penicillins are a class of antibiotics including ampicillin and carbenicillin. These two medications are useful against many bacteria. According to "Pharmacotherapy: A Pathophysiologic Approach," carbenicillin only has an indication for treatment of urinary tract infections. The extended spectrum penicillins include Augmentin (amoxicillin-clavulanate) and Zosyn (piperacillin-tazobactam), and have greater activity against bacteria that cause UTIs. Augmentin is preferred in cases where the bacteria are resistant to other medications. Zosyn is available as an intravenous medication only, and may be used in patients with kidney impairment.
Cephalosporins
Cephalosporins are a class of antibiotics which include cephalexin, cefaclor, cefuroxime, cefixime, among others. These medications do not have any advantage over other medications used for the treatment of UTIs and are more expensive, explains "Pharmacotherapy: A Pathophysiologic Approach." Typically, they may be used in cases when the bacteria are resistant to Bactrim and penicillins.
Fluoroquinolones
Fluoroquinolones are a class of antibiotics that can treat UTIs caused by many bacteria. These medications include ciprofloxacin, norfloxacin, and levofloxacin. Fluoroquinolones are very effective in treating complicated UTIs, including pyelonephritis and prostatitis. However, fluoroquinolones can not be used in children or pregnant women.
Nitrofurantoin
Nitrofurantoin is a prescription antibiotic that may be used for treatment and prevention of UTIs. It is has an advantage over other antibiotics because bacteria do no develop resistance to the medication even after long duration of treatments. Side effects, such as diarrhea, nausea, abdominal pain, and pulmonary reactions, may limit its use.
Aminoglycosides
Aminoglycosides are a class of antibiotics available as intravenous administration only. They include gentamicin, tobramycin, amikacin and netilmicin. Aminoglycosides are used for serious infections that may spread to other areas of the body. Amikacin is usually used in cases where the bacteria are resistant to multiple medications.
References
- "Drug Information Handbook 15th Edition"; Lacy, Charles F., Armstrong, Lora L., et al; 2007
- "Pharmacotherapy: A Pathophysiologic Approach"; Dipiro, Joseph T., Talbert,Robert L., et al; 2008
