ADVERSE REACTIONS

Gastrointestinal: anorexia, nausea, epigastric distress, vomiting, diarrhea, glossitis, black hairy tongue, dysphagia, enterocolitis, and inflammatory lesions (with Candida overgrowth) in the anogenital region.

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 taken medication immediately before going to bed (seeDOSAGE AND ADMINISTRATION).

Teeth: permanent discoloration of teeth may be caused during tooth development. Enamel hypoplasia has been reported (seeWARNINGS).

Skin: maculopapular and erythrematous rashes. Exfoliative dermatitis has been reported. Onycholysis and discoloration of the nails have been reported. Photosensitivity is discussed inWARNINGS.

Renal Toxicity: an increase in BUN has been reported and is dose related.

Liver: hepatotoxicity and liver failure have been observed in patients receiving tetracycline and in tetracycline-treated patients with renal impairment.

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

Blood: hemolytic anemia, thrombocytopenia, thrombocytopenic purpura, neutropenia and eosinophilia 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 studies are known to occur.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800- FDA-1088 or contact Breckenridge Pharmaceutical, Inc. at 1-800-367-3395.

PRECAUTIONS

General

As with other antibacterials, use of this drug may result in overgrowth of nonsusceptible organisms, including fungi. If superinfection occurs, discontinue antibacterial and institute appropriate therapy.

Treat all infections due to Group A beta-hemolytic streptococci for at least ten days.

Perform incision and drainage or other surgical procedures in conjunction with antibacterial therapy, when indicated.

Prescribing tetracycline in the absence of proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug- resistant bacteria.

Information for Patients

Counsel patients that antibacterial drugs including tetracycline should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When tetracycline is prescribed to treat a bacterial infection, tell patients that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by tetracycline or other antibacterial drugs in the future.

Laboratory Tests

In sexually transmitted infections, when coexistent syphilis is suspected, perform dark field examinations before treatment is started and the blood serology repeated monthly for at least four months.

Drug Interactions

Since bacteriostatic drugs may interfere with the bactericidal action of penicillin, it is advisable to avoid giving tetracycline in conjunction with penicillin or other bactericidal antibacterials.

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.

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

Absorption of tetracyclines is impaired by antacids containing aluminum, calcium or magnesium and preparations containing iron, zinc, or sodium bicarbonate.

Concurrent use of tetracycline may render oral contraceptives less effective.

Carcinogenesis, Mutagenesis, Impairment of Fertility

Long-term animal studies are currently being conducted to determine whether tetracycline hydrochloride has carcinogenic potential. Some related antibacterials (oxytetracycline, minocycline) have shown evidence of oncogenic activity in rats.

In two in vitro mammalian cell assay systems (L 51784y mouse lymphoma and Chinese hamster lung cells), there was evidence of mutagenicity with tetracycline hydrochloride.

Tetracycline hydrochloride had no effect on fertility when administered in the diet to male and female rats at a daily intake of approximately 400 mg/kg/day, roughly 8 times the highest recommended human dose based on body surface area.

Pregnancy

Teratogenic Effects

Pregnancy Category D

(seeWARNINGS)

Nonteratogenic Effects

(seeWARNINGS)

Pregnant women with renal disease may be more prone to develop tetracycline- associated liver failure.

Labor and Delivery

The effect of tetracyclines on labor and delivery is unknown.

Nursing Mothers

Because of potential for serious adverse reaction in nursing infants from tetracyclines, a decision should be made whether to discontinue the drug, taking into account the importance of the drug to the mother (see WARNINGS).

Pediatric Use

SeeWARNINGS andDOSAGE AND ADMINISTRATION.

OVERDOSAGE

In case of overdosage, discontinue medication, treat symptomatically and institute supportive measures. Tetracycline is not dialyzable.