Tetracycline Contraindications and Precautions
Tetracycline is contraindicated in patients with known tetracyclines hypersensitivity. Topical tetracycline preparations contain sodium sulfites. Oral dosage forms may contain tartrazine dye. These preparations should be used with caution in patients with a known sulfite hypersensitivity or tartrazine dye hypersensitivity. Sensitivity reactions are more common in asthmatic than in non-asthmatic patients.
Tetracycline is classified pregnancy category D. All tetracyclines have a detrimental effect on the skeletal development and bone growth of the fetus or child. They should not be used in the second half of pregnancy unless benefits from treatment outweigh the risks to the fetus, and their use should be considered only with extreme caution. Tetracyclines also have a serious effect on the dentin and enamel of developing teeth, causing permanent yellow or brown discoloration and enamel hypoplasia. Except when other therapy is ineffective, use in pediatrics, especially in children under 8 years, should be avoided.
Tetracyclines are distributed into breast milk, although tetracyclines can form nonabsorbable complexes with the calcium in breast milk. In general, tetracycline antibiotics should not be used in breast-feeding mothers because there is still the risk of causing teeth discoloration, enamel hypoplasia, inhibition of linear skeletal growth, oral and vaginal thrush, or photosensitivity reactions in the nursing infant.
Tetracycline should not be used in patients who have severe renal disease, unless dose and frequency are modified accordingly. Urinary clearance can be reduced in patients with renal impairment or renal failure; serum half-lives of as long as 120 hours have been reported. Doxycycline or minocycline is preferred over tetracycline in these patients.
Dose adjustment may be required in patients with hepatic disease because hepatic excretion of tetracycline into bile can be delayed in these patients.
Photosensitivity is a risk of tetracycline therapy and can occur when patients treated with tetracycline are exposed to sunlight (UV) exposure. Tetracycline should be discontinued at the first sign of erythema. Photosensitivity reactions are believed to be due to accumulation of the drug in the skin and are mostly phototoxic in nature, but photoallergic reactions also can occur. Reactions can develop from within a few minutes to up to several hours after exposure and will last for 1-2 days after discontinuation of the drug. It is generally agreed that sunscreens provide limited protection for this reaction. Direct sunlight (UV) exposure should be avoided or minimized.
In patients undergoing surgery with methoxyflurane anesthesia, concurrent use of tetracycline can increase the risk of nephrotoxicity (sometimes fatal).
Ophthalmic tetracycline and ophthalmic corticosteroid therapy are not recommended for combination therapy. Combination therapy may mask the clinical signs of bacterial, viral, or fungal infections. Corticosteroids may suppress hypersensitivity reactions to tetracycline therapy.
Treatment with an antibacterial agent, including tetracycline, can alter the normal flora of the colon and allow overgrowth of Clostridium difficile. Diarrhea, particularly if severe and/or persistent, occurring during treatment or in the initial weeks following treatment may be symptomatic of Clostridium difficile-associated disease, the most severe form of which is pseudomembranous colitis. Pseudomembranous colitis has been reported to occur with various antibiotics, including tetracyclines. If pseudomembranous colitis is suspected, tetracycline should be stopped immediately and the patient should be treated with supportive and specific treatment without delay. Products inhibiting peristalsis are contraindicated in this clinical situation.
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