Gastrointestinal: anorexia, epigastric distress, nausea, vomiting, diarrhea, bulky loose stools, stomatitis, sore throat, glossitis, black hairy tongue, dysphagia, hoarseness, enterocolitis, and inflammatory lesions (with candidal overgrowth) in the anogenital region, including proctitis and pruritus ani. Rare instances of esophagitis and esophageal ulceration have been reported in patients receiving particularly the capsule and also the tablet forms of tetracyclines. Most of the patients were reported to have medication immediately before going to bed (see DOSAGE AND ADMINISTRATION). These reactions have been caused by both the oral and parenteral administration of tetracyclines but are less frequent after parenteral use.

Skin and Skin Structures: maculopapular and erythematous rashes. Exfoliative dermatitis has been reported but is uncommon. Onycholysis and discoloration of the nails have been reported rarely. Photosensitivity has occurred. (See WARNINGS).

Renal Toxicity: increases in BUN have been reported and are apparently dose-related. (See WARNINGS.)

Hepatic Cholestasis: has been reported rarely, and is usually associated with high dosage levels of tetracycline.

Hypersensitivity Reactions: Anaphylaxis; serum sickness-like reactions, as fever, rash, and arthralgia; urticaria, angioneurotic edema, anaphylactoid purpura, pericarditis, exacerbation of systemic lupus erythematosus.

Hematological: Blood: anemia, hemolytic anemia, thrombocytopenia, thrombocytopenic purpura, neutropenia and eosinophilia have been reported.

Miscellaneous: Dizziness and headache have been reported.

When given over prolonged periods, tetracyclines have been reported to produce brown-black microscopic discoloration of thyroid glands. No abnormalities of thyroid function are known to occur. Bulging fontanels in infants and intracranial hypertension in adults have been reported. (See PRECAUTIONS-General.)

Read the Sumycin (tetracycline) Side Effects Center for a complete guide to possible side effects »

PENICILLIN-Since bacteriostatic drugs like tetracycline may interfere with the bactericidal action of penicillin, it is advisable to avoid giving tetracycline in conjunction with penicillin.

ANTICOAGULANTS-Because the tetracyclines have been shown to depress plasma prothrombin activity, patients who are on anticoagulant therapy may require downward adjustment of their anticoagulant dosage.

ANTACIDS AND IRON CONTAINING PRODUCTS-Absorption of tetra- cycline is impaired by antacids containing aluminum, calcium, or magnesium, and iron containing preparations.

ORAL CONTRACEPTIVES-Concurrent use of tetracycline may render oral contraceptives less effective.

METHOXYFLURANE-The concurrent use of tetracycline and methoxyflurane has been reported to result in fatal renal toxicity.

Last reviewed on RxList: 2/8/2008
This monograph has been modified to include the generic and brand name in many instances.