Tetracyclines

≥Tetracyclinedoxycycline and minocycline.

Tetracycline and minocycline

Tetracyclines are active against infections caused by the following:

• Rickettsiae

• Spirochetes (eg, Treponema pallidum, Borrelia burgdorferi)

• Helicobacter pylori

• Vibrio species

• Yersinia pestis

• Francisella tularensis

• Brucella species

• Bacillus anthracis

• Plasmodium vivax

• Plasmodium falciparum

• Mycoplasma species

• Chlamydia and Chlamydophila species

• Some methicillin-resistant Staphylococcus aureus

About 5 to 10% of pneumococcal strains and many group A beta-hemolytic streptococci, many gram-negative bacillary uropathogens, and penicillinase-producing gonococci are resistant.

S. aureus infections.

for all of the following because it is better tolerated and can be given twice a day:

• Infections caused by rickettsiae or Anaplasma, Chlamydia, Chlamydophila, Ehrlichia, Mycoplasma, or Vibrio species

• Acute exacerbations of chronic bronchitis

• Lyme disease

• Brucellosis

• Anthrax

• Plague

• Tularemia

• Granuloma inguinale

• Syphilis

• Prophylaxis of malaria caused by chloroquine-resistant P. falciparum

Tetracyclines are contraindicated in patients who have had an allergic reaction to them.

doxycycline acceptable for all ages (1). A study of children < 8 years of age who were treated with a short course of doxycycline for suspected Rocky Mountain spotted fever found no evidence of tooth staining or enamel defects compared to children who had not received doxycycline (2, 3).

Hepatotoxicity may occur in pregnant women, particularly after IV administration and in those with azotemia or pyelonephritis. Taking high doses during pregnancy can lead to fatty degeneration of the liver, which may be fatal.

Adverse effects of tetracyclines include

• Gastrointestinal disturbances

• Candidiasis

• Photosensitivity

• Bone and dental effects in children

• Fatty liver

All oral tetracyclines cause nausea, vomiting, and diarrhea and can cause candidal superinfections. If not swallowed with water, tetracyclines can cause esophageal erosions.

Photosensitivity due to tetracyclines may manifest as an exaggerated sunburn reaction.

Contraindications), hypoplasia of dental enamel, and abnormal bone growth in children < 8 years. In infants, tetracyclines may cause idiopathic intracranial hypertension and bulging fontanelles.

Excessive blood levels due to use of high doses or renal insufficiency may lead to fatal acute fatty degeneration of the liver, especially during pregnancy.

minocycline has been associated with development of autoimmune disorders such as systemic lupus erythematosus and polyarteritis nodosa, which may be reversible. Minocycline may also cause drug reaction with eosinophilia and systemic symptoms (DRESS), which is characterized by fever, rash, lymphadenopathy, hepatitis, atypical lymphocytosis, eosinophilia, and thrombocytopenia.

Tetracyclines (except for doxycycline) can exacerbate azotemia, hyperphosphatemia, and metabolic acidosis in patients with renal insufficiency. Although doxycycline

Expired tetracycline pills can degenerate and, if ingested, cause Fanconi syndrome. Patients should be instructed to discard the antibiotics when they expire.

Tetracyclines may decrease the effectiveness of oral contraceptives and potentiate the effects of oral anticoagulants.