What is it?

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. Anthrax is a very dangerous type of bacteria. Doxycycline is a type of drug that fights off many types of infections by slowing the growth of bacteria. Because it can stop the production of bacteria, doxycycline is used to treat acne.

How does it 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. In treating acne, Doxycycline is thought to slow the production of the bacteria, Propionibacterium acnes. This bacteria is believed to be important in the formation of acne. Doxycycline may also work to treat acne by controlling inflammatory reactions in the body. Although different people respond to medications at different rates, acne should respond to Doxycycline by 6 weeks. The normal time frame for acne to respond to doxycycline is 3 to 6 weeks. In some patients, acne may get worse before it gets better.

What type of drug is Doxycycline?

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.

Who should not take Doxycycline?

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.

What else is Doxycycline called?

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.