Doxycycline for a UTI (Urinary Tract Infection)
Doxycycline can be used to treat a number of different types of infections caused by bacteria, including a urinary tract infection (UTI). Doxycycline is part of a class of drugs called tetracyclines; it works by decreasing bacteria's ability to make protein, which bacteria need to live. This activity does not directly kill the bacteria, but it does inhibit their growth and multiplication, which gives the immune system a chance to fight the infection.
Doxycycline is approved for use in adults and children as young as 8 years old. Permanent discoloration and altered development of teeth has been reported in children younger than 8 years old who have used tetracyclines, such as doxycycline.
The recommended doxycycline dosage for most types of bacterial infections in adults is 100 mg to 200 mg per day for 7 to 14 days. In children ages 8 years old or older, your healthcare provider will prescribe a doxycycline dosage based on a weight chart, usually about 1 to 2 mg per pound of body weight per day. The dose is divided and taken for 7 to 14 days. Children should generally be limited to 200 mg or less of doxycycline per day.
(Click Doxycycline Uses and Doxycycline Dosage for more detail on using this drug for UTIs. These articles also cover other uses of doxycycline, and describe some general dosing guidelines for these various uses.)