Acne, urinary tract infections, intestinal infections, respiratory infections, eye infections, gonorrhea, chlamydia, syphilis, periodontitis (gum disease), and other bacterial infections are treated with doxycycline. When treating bacterial infections, doxycycline inhibits bacterial growth and is thought to have an anti-inflammatory effect when used for other conditions. Doxycycline is a type of antibiotic known as tetracycline.

As directed by your doctor, take this medication by mouth with or without food once daily. If you are taking this medication as a liquid suspension, shake the bottle thoroughly before each dose. Use a special measuring device/spoon to carefully measure the dose. If you use a regular spoon, you may not get the correct dose. 

The dose is determined by your medical condition and response to treatment. Dosage for children is also based on weight. In general, children’s doses should not exceed 600 milligrams per day unless otherwise directed by a doctor.