From the FDA Drug Label
Urinary tract infections caused by susceptible strains of Escherichia coli, Klebsiella, etc. Infections due to Campylobacter fetus. Other infections caused by susceptible gram-negative organisms such as E. coli, Enterobacter aerogenes, Shigella sp., Acinetobacter sp., Klebsiella sp., and Bacteroides sp.
- Tetracycline can be used to treat a UTI if the urine culture suggests that it is sensitive to tetracycline, as it is indicated for urinary tract infections caused by susceptible strains of certain bacteria 1.
- The key is that the bacteria must be susceptible to tetracycline.
- Tetracycline hydrochloride tablets are an option for treating UTIs caused by susceptible gram-negative organisms.
From the Research
Doxycycline is the preferred tetracycline antibiotic for treating urinary tract infections (UTIs) when the urine culture shows sensitivity to tetracyclines. The typical dosage is 100 mg twice daily for 7-10 days for uncomplicated UTIs, though treatment duration may be adjusted based on infection severity. Doxycycline is preferred over other tetracyclines for UTIs because it achieves higher urinary concentrations and has better bioavailability, as noted in various studies 2, 3, 4. It works by inhibiting bacterial protein synthesis, preventing bacterial growth and reproduction. Patients should take doxycycline with plenty of water and remain upright for 30 minutes after taking it to prevent esophageal irritation. It's essential to complete the full course of antibiotics even if symptoms improve before finishing treatment. Doxycycline may cause photosensitivity, so sun protection is advised during treatment. While tetracyclines are not typically first-line agents for UTIs (fluoroquinolones or trimethoprim-sulfamethoxazole usually are), doxycycline can be effective when susceptibility testing indicates it would work or when first-line options cannot be used, as discussed in 2, 4, 5.
Some key points to consider when treating UTIs with doxycycline include:
- The importance of susceptibility testing to ensure the bacteria are sensitive to tetracyclines 2, 4
- The need to complete the full course of antibiotics to prevent recurrence and resistance 2, 4, 5
- Potential side effects, such as photosensitivity, and how to manage them 3, 4
- The role of doxycycline in the treatment of UTIs, particularly when first-line options are not suitable 2, 4, 5
It's also important to note that the treatment of UTIs should be guided by the most recent and highest-quality evidence, and doxycycline is a viable option when used appropriately, as supported by studies such as 2 and 4.