Detailed Drug Information:

DRUG CLASS AND MECHANISM: Doxycycline is a syntheticbroad-spectrum antibiotic derived from tetracycline. It is effectiveagainst a wide variety of bacteria, such as Hemophilus influenzae,Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydia psittaci,Chlamydia trachomatis, Neisseria gonorrhoea, and many others.

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 ofinfections, including respiratory tract infections due to Hemophilusinfluenzae, Streptococcus pneumoniae, or Mycoplasma pneumoniae. It also isused 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 dailyfor 7 to 14 days. Sometimes, the first dose is given as a "doubledose," that is, twice as large as the remainder of the doses.

DRUG INTERACTIONS: It is recommended that doxycycline not betaken at the same time as aluminum-, magnesium-, or calcium-basedantacids, 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 causeexcessive "thinning" of the blood, necessitating a reduction inthe dose of warfarin. Phenytoin (Dilantin), carbamazepine (Tegretol), andbarbiturates (such as phenobarbital) may enhance the metabolism(destruction) of doxycycline thus making it less effective.

PREGNANCY: Tetracycline antibiotics, such as doxycycline, canhave toxic effects on development of bone in the fetus. Therefore,tetracyclines are not recommended during pregnancy unless there is noother appropriate antibiotic.

NURSING MOTHERS: Doxycycline is secreted into breast milk. Sincetetracyclines can cause decreased bone, the use of tetracyclines innursing mothers is of concern. The physician must decide whether torecommend that a nursing mother discontinue nursing during treatment withtetracyclines or to choose a different antibiotic.

SIDE EFFECTS: Doxycycline is generally well-tolerated. The mostcommon side effects are diarrhea or loose stools, nausea, abdominal pain,and vomiting. Tetracyclines, such as doxycycline, may cause toothdiscoloration if used in persons below 8 years of age. Exaggerated sunburncan occur with tetracyclines; therefore, sunlight should be minimizedduring treatment.