Tetracycline, antibiotic drug used to treat various bacterial infections, including urinary tract infections, Rocky Mountain spotted fever, trachoma (a chronic eye infection), and gonorrhea. Tetracycline is also sometimes used to take care of early stages of Lyme disease, acne, gum disease, and certain gastrointestinal ulcers. It works by interfering with the invading bacteria’s ability to form essential proteins, thereby halting their growth.
Tetracycline is available by prescription in capsule form, taken orally, and in a reconstituted powder solution, applied topically. Typical capsule dosages range from 1 to 2 2 g per day, taken in one to four doses, with a recommended maximum of 4 g each day. Unless this medication causes stomach upset, it should be taken on an empty stomach (one hour before or two hours after a meal) with a full glass of water. It should not be combined with milk or other dairy products. Tetracycline usually relieves symptoms after 48 hours of treatment, but it should be taken for the prescribed length of time to avoid recurrence of infection.
Patients with severe liver disease or pregnant or breast-feeding women should not take this drug. Patients with impaired liver or kidney function or with systemic lupus erythematosus should use tetracycline with caution.
Possible side effects include diarrhea, nausea, vomiting, skin rash, itching, light sensitivity, facial swelling, headache, blurred vision, chest pain, sore throat, difficulty swallowing, or in infants, a bulging soft spot on the head. Children may develop discolored teeth with long-term make use of.
Tetracycline may interact adversely with antacids and other common gastrointestinal medications, oral contraceptives, blood thinners, lithium, penicillin, isotretinoin, cholestyramine, and sucralfate.
Chlortetracycline was the first tetracycline discovered, in 1948. Since then five additional tetracyclines have been isolated or derived (oxytetracycline, tetracycline, demeclocycline, doxycycline and minocycline), but only the last four are available for systemic use in the United States. Of these four agents, doxycycline and minocycline are the most frequently prescribed. Research to find tetracycline analogues lead to the development of the glycylcyclines. Doxycycline is one of the most active tetracyclines and is the most often used clinically since it possesses many advantages over traditional tetracycline and minocycline. In contrast to many other antibiotics, tetracyclines are infrequently inactivated biologically or altered chemically by resistant bacteria. The tetracyclines are considered broad-spectrum bacteriostatic antibiotics that are used to treat infection caused by many aerobic gram-positive and gram-negative bacteria. However, they also have activity against many atypical pathogens, including Rickettsia spp., Borrelia spp., Coxiella burnetii, Treponema spp., Chlamydophila and Chlamydia spp., Mycoplasma pneumoniae, Plasmodium spp., Vibrio cholerae, Vibrio vulnificus, Brucella spp., Calymmatobacterium granulomatis, Leptospira, Borrelia burgdorferi, Borrelia recurrentis, Burkholderia pseudomallei, Mycobacterium marinum, and Entamoeba histolytica. These drugs have little activity against fungi and viruses.