Doxycycline is an antibiotic that is used in the treatment of a number of types of infections caused by bacteria and protozoa. It is useful for bacterial pneumonia, acne, chlamydia infections, early Lyme disease, cholera and syphilis. It is also useful for the treatment of malaria when used with quinine and for the prevention of malaria. Doxycycline can be used either by mouth or intravenously.
Common side effects include diarrhea, nausea, vomiting, a red rash, and an increased risk of a sunburn. If used during pregnancy or in young children may result in permanent problems with the teeth including changes in their color. Its use during breastfeeding is probably safe. Doxycycline is a broad-spectrum antibiotic of the tetracycline class. Like other agents of this class it kills bacteria and protozoa by inhibiting protein production.
Doxycycline was patented in 1957 and came into commercial use in 1967. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Doxycycline is available as a generic medicine and is generally inexpensive. The wholesale cost in the developing world is between 0.01 and 0.04 USD per pill. In the United States 10 days of treatment is about 14 USD, however some in 2014 were selling it for more than 3.00 to 10.00 USD per pill.