doxycycline  GENERIC NAME: doxycycline BRAND NAME: Vibramycin DRUG CLASS AND MECHANISM: Doxycycline is a synthetic broad-spectrum antibiotic derived from tetracycline. It is effective against a wide variety of bacteria, such as Hemophilus influenzae, Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydia psittaci, Chlamydia trachomatis, Neisseria gonorrhoea, and many others. PRESCRIPTION: yes GENERIC AVAILABLE: yes PREPARATIONS: Capsules: 50mg, 100mg; Tablets: 100mg; Suspension: 25 mg/teaspoon; Syrup: 50 mg/teaspoon. STORAGE: Capsules should be kept below 30°C (86°F). The suspension should be refrigerated and shaken prior to each use. PRESCRIBED FOR: Doxycycline is used for many different types of infections, including respiratory tract infections due to Hemophilus influenzae, Streptococcus pneumoniae, or Mycoplasma pneumoniae. It also is used for the treatment of nongonococcal urethritis (due to Ureaplasma), Rocky mountain spotted fever, typhus, chancroid, cholera, brucellosis, anthrax, syphilis, and acne. DOSING: The absorption of doxycycline is not markedly affected by food, and therefore, it can be taken with meals. For most infections, doxycycline is taken once or twice daily for 7 to 14 days. Sometimes, the first dose is given as a "double dose," that is, twice as large as the remainder of the doses. DRUG INTERACTIONS: It is recommended that doxycycline not be taken at the same time as aluminum-, magnesium-, or calcium- based antacids, such as Mylanta, Maalox, Tums, or Rolaids because, like food, these medications bind doxycycline in the intestine. Similarly, doxycycline should not be taken with minerals (such as calcium or iron), with bismuth subsalicylate (Pepto Bismol). Doxycycline may enhance the activity of warfarin (Coumadin) and cause excessive "thinning" of the blood, necessitating a reduction in the dose of warfarin. Phenytoin (Dilantin), carbamazepine (Tegretol), and barbiturates (such as phenobarbital) may enhance the metabolism (destruction) of doxycycline thus making it less effective. PREGNANCY: Tetracycline antibiotics, such as doxycycline, can have toxic effects on development of bone in the fetus. Therefore, tetracyclines are not recommended during pregnancy unless there is no other appropriate antibiotic. NURSING MOTHERS: Doxycycline is secreted into breast milk. Since tetracyclines can cause decreased bone, the use of tetracyclines in nursing mothers is of concern. The physician must decide whether to recommend that a nursing mother discontinue nursing during treatment with tetracyclines or to choose a different antibiotic. SIDE EFFECTS: Doxycycline is generally well-tolerated. The most common side effects are diarrhea or loose stools, nausea, abdominal pain, and vomiting. Tetracyclines, such as doxycycline, may cause tooth discoloration if used in persons below 8 years of age. Exaggerated sunburn can occur with tetracyclines; therefore, sunlight should be minimized during treatment.