Generic name: Doxycycline hyclate

Other brand names: Vibramycin, Vibra-Tabs

Doxycycline has been trademarked (given brand names) by several companies. These names are as follows: Doxycycline hyclate, Doryx, Doxy-Caps, Doxy-Tabs, Vibramycin, and Vibra-Tabs. By law, the brand name versions of a generic drug all need to have the same ingredients as the generic version. The only difference between medications with brand names and those without brand names is the price.

The prefix "doxy-" in "doxycycline" refers to the chemical makeup of this drug, which is a-6-Deoxy-5-hydroxytetra-cycline. So "doxy-" is just a short way of saying "Deoxy." "Cycline" refers to the fact that this drug is one of the tetracyclines.

What is Doxycyline used for?

Doxycycline is a broad-spectrum tetracycline antibiotic used against a wide variety of bacterial infections, including Rocky Mountain spotted fever and other fevers caused by ticks, fleas, and lice; urinary tract infections; trachoma (chronic infections of the eye); and some gonococcal infections in adults. It is an approved treatment for inhalational anthrax. It is also used with other medications to treat severe acne and amoebic dysentery (diarrhea caused by severe parasitic infection of the intestines).

Doxycycline may also be taken for the prevention of malaria on foreign trips of less than 4 months' duration.

Occasionally doctors prescribe doxycycline to treat early Lyme disease and to prevent "traveler's diarrhea." These are not yet officially approved uses for this drug.

Doxycycline is the generic name (meaning it is not a brand name) for a medication that has been in the news since October of 2001 because it is used to treat anthrax, a type of biological infection. Doxycycline is a type of drug that fights off many types of infections by slowing the growth of bacteria. Anthrax is a type of bacteria.

How does Doxycycline work?

Doxycycline works by stopping the production of protein that the bacteria needs to survive. Without being able to produce the protein, the bacteria cannot perform essential functions such as growth and repair. This causes them to eventually stop growing and die.

Doxycycline is a type of drug known as a tetracycline antibacterial. Antibacterial means that the drug fights bacteria. The word "tetracycline" refers to the chemical structure of the drug. That is, drugs that are in the tetracycline class have four 6-membered rings that make up their basic structure. This makes sense when you consider that the word "tetra" in Latin means "four," and the word "cycline" comes from the Greek word, "kyklos," meaning "circle." Put the two words together and you get "four circles (rings)." Some tetracyclines occur naturally, whereas others are part natural and part man-made. Doxyclyine is part natural and part man-made, which is why it is called a semisynthetic (part man-made) tetracycline. Specifically, doxycycline is made by changing the chemical makeup of a naturally occurring tetracycline known as oxytetracycline.

Side Effects

Doxycline has numerous side effects such as photosensitivity (an abnormal sensitivity to light), problems with the digestive tract (the tube in the body running from the mouth to the anus), and/or the development of another infection. In children under the age of 8, their teeth may become discolored from using this drug.

Drug Interactions

Doxycycline is known to interact with other drugs. You should always contact your doctor to ask if the particular medications that you are taking interact with doxycycline. Doxycycline is known to interact with other antibiotics (drugs that fight infections), antiviral drugs (drugs that fight against viruses), and antacids (drugs that neutralize stomach acids). Digitalis drugs, which are drugs extracted from plants and used to treat heart conditions, are also known to interact with doxycycline. Medications taken by mouth that are used to prevent pregnancy can interact with doxycycline, as can calcium and mineral supplements. Calcium is a type of metallic element that is important for normal body functioning to take place. Minerals are types of natural substances that are needed for the body to function properly.

Names of some specific medications that are known to interact with doxycycline are sodium bicarbonate (an antacid), cefixime (an antibiotic), bismuth salicylate (an antacid and antidiarrhea drug), warfarin (a drug that prevents blood from clumping together), lithium carbonate (a drug that reduces mania, which is an abnormal, overly excited state), tiopronin (drugs that prevent kidney stones), etretinate (a drug used to treat an abnormal skin condition called psoriasis in which red scales are present on the body and covered with silvery scales), desmopressin (a drug that prevents bleeding and decreases the amount of water that enters the urine), and cholestyramine (a drug that lowers cholesterol). Cholesterol is a waxy, fatty substance found in animal tissues.

When should Doxycycline NOT be taken?

Not everyone should take Doxycycline, such as people with dysfunction of the liver or kidneys. People who are hypersensitive to doxycycline or other tetracyclines obviously should not take this drug either. Pregnant women and children under age 8 are typically not given this drug.

Additonal Information

Doxycycline has been trademarked (given brand names) by several companies. These names are as follows: Doxycycline hyclate, Doryx, Doxy-Caps, Doxy-Tabs, Vibramycin, and Vibra-Tabs. By law, the brand name versions of a generic drug all need to have the same ingredients as the generic version. The only difference between medications with brand names and those without brand names is the price.