Doxycycline is a member of the tetracycline antibiotics group and is commonly used to treat a variety of infections. Doxycycline is a semi-synthetic tetracycline invented and clinically developed in the early 1960s by Pfizer Inc.

As well as the general indications for all members of the tetracycline antibiotics group, Doxycycline is frequently used to treat chronic prostatitis, sinusitis, syphilis, chlamydia, pelvic inflammatory disease, acne and rosacea. In addition it is used in the treatment and prophylaxis of Bacillus anthracis (anthrax) and in prophylaxis against malaria. It should not be used alone for initial treatment of malaria, even when the parasite is doxycyline-sensitive, because the antimalarial effect of doxycyline is delayed. This delay is related to its mechanism of action. Its mechanism of action against malaria is to specifically impair in the progeny the apicoplast genes resulting in their abnormal cell division.

It is also effective against Yersinia pestis (the infectious agent of bubonic plague) and is prescribed for the treatment of Lyme disease, ehrlichiosis and Rocky Mountain spotted fever. In fact, because doxycycline is one of the few medications that are effective in treating Rocky Mountain spotted fever (with the next best alternative being chloramphenicol), doxycycline is indicated even in use in children for this illness. Otherwise, doxycycline is not indicated in the use in children under the age of 8 years. Doxycycline, like other antibiotics, will not work for colds, flu, or other viral infections.

Elephantiasis is a disease caused by a nematode (worm) Wuchereria bancrofti. It causes swollen limbs and genitals (Filariasis) and affects over 120 million people in the world. Previous anti-nematode treatments have been limited by poor levels of effectiveness, drug side effects and high costs. Doxycycline was shown in 2003 to kill the symbiotic Wolbachia bacteria upon which the nematodes are dependent. Field trials in 2005 showed that Doxycycline almost completely eliminates blood-borne filaria when given for an 8 week course.

When bacteriologic testing indicates appropriate susceptibility to the drug, doxycycline may be used to treat:

    * Escherichia coli
    * Enterobacter aerogenes (formerly Aerobacter aerogenes)
    * Lyme Disease
    * Acne
    * Shigella species
    * Acinetobacter species (formerly Mima species and Herellea species)
    * Respiratory tract infections caused by Haemophilus influenzae
    * Respiratory tract and urinary tract infections caused by Klebsiella species
    * Upper respiratory infections caused by Streptococcus pneumoniae (formerly Diplococcus pneumoniae)
    * Methicillin-resistant Staphylococcus aureus (MRSA) infections

Before taking any prescription medicine, it is important that you consult your doctor!