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 and prevent:
Unlike some other members of the tetracycline group, it may be used in those with renal impairment.
Previously, it was believed that doxycycline impairs the effectiveness of many types of hormonal contraception due to CYP450 induction. Recent research has shown no significant loss of effectiveness in oral contraceptives while using most tetracycline antibiotic (including doxycycline), although many physicians still recommend the use of barrier contraception for people taking the drug to prevent unwanted pregnancy.
It should be taken with a full glass of water and patients should be upright for at least 30 minutes after administration to prevent irritation of the esophagus and stomach. Also, there is a slim risk of liver damage during prolonged use of the drug. It is also recommended that it be taken with a small meal of a non-dairy nature if upset stomach, nausea, or fatigue occurs.
Doxycycline is not approved for use in children under the age of 8 years for two reasons: 1) it can cause permanent yellowing or graying of the teeth, and 2), according to CDC patient information on doxycycline, it can inhibit bone growth in premature infants during the time the medication is taken; this last effect disappears when the doxycycline treatment is over. Specific exceptions are made for potentially fatal illnesses where the benefits outweigh the risks and there are few or no other alternatives, such as with Rocky Mountain spotted fever and anthrax. It should also not be used in pregnant and nursing women, as the drug can cause damage to a fetus and nursing child.
Doxycycline is also used in "Tet-on" and "Tet-off" tetracycline controlled transcriptional activation to regulate transgene expression in organisms and cell cultures.
Other experimental applications include: