Tetracycline Hydrochloride

Indications

Tetracycline Hydrochloride is used for: Acne, Lyme disease, Uncomplicated gonorrhea, Syphilis, Psittacosis, Q fever, Pleural effusions, Rocky Mountain spotted fever, Lymphogranuloma venereum, Mycoplasma pneumoniae, Trachoma, Nongonococcal urethritis

Adult Dose

Oral Susceptible infections Adult: 250-500 mg 6 hrly. Max: 4 g/day. Acne Adult: 250-500 mg daily, in divided doses, for at least 3 mth. Syphilis Adult: 500 mg 4 times daily for 15 days. Gonorrhoea Adult: 500 mg 4 times daily for 7 days. Vibrio Cholera Adult: 500 mg 4 times daily for 3 days Brucellosis Adult: 500 mg 4 times daily for 3 wk in combination w/ streptomycin. Hepatic impairment: Max: 1 g daily.

Child Dose

Oral Children : <8 years: Not recommended >8 y: 25–50 mg/kg/day q6h not to exceed 3 g/day

Renal Dose

Renal impairment CrCl 50-80 mL/min: Dose frequency q8-12hr CrCl 10-50 mL/min: Dose frequency q12-24hr CrCl <10 mL/min: Dose frequency q24hr

Administration

Should be taken on an empty stomach. Take on an empty stomach 1 hr before or 2 hr after meals w/ a full glass of water, in upright position. May be taken w/ meals to reduce GI discomfort.

Contra Indications

Hypersensitivity; pregnancy, lactation, children; renal impairment.

Precautions

Patient w/ pre-existing SLE, myasthenia gravis. Hepatic and mild to moderate renal impairment. Pregnancy. Patient Counselling Avoid direct exposure to sunlight or UV light. Monitoring Parameters Monitor renal, hepatic and haematologic function test, temp, WBC, cultures and sensitivity, appetite, mental status.

Pregnancy-Lactation

Pregnancy Avoid 1st trimester; contraindicated 2nd and 3rd trimesters Pregnant women with renal disease may be more prone to develop tetracycline-associated liver failure The effect of tetracyclines on labor and delivery is unknown Lactation Short-term use of tetracycline is acceptable in nursing mothers A number of reviews have stated that tetracycline is contraindicated during breastfeeding because of possible staining of infants' dental enamel or bone deposition of tetracyclines; however, a close examination of available literature indicates that there is not likely to be harm in short-term use of tetracycline during lactation because milk levels are low and absorption by the infant is inhibited by the calcium in breast milk Tetracycline is excreted into breast milk in low concentrations (milk:plasma ratio ranges between 0.25 and 1.5) NIH LactMed and the American Academy of Pediatrics classifies tetracycline as compatible with breastfeeding

Interactions

Impaired absorption w/ antacids containing divalent and trivalent cations (e.g. Al, Ca, Mg), Fe, Zn and Na bicarbonate preparations, kaolin-pectin, bismuth subsalicylate, sucralfate, strontium ranelate, colestipol and colestyramine. May interfere w/ the bactericidal action of penicillin. May potentiate the effect of anticoagulants. May decrease efficacy of oral contraceptives. Nephrotoxic effects may be exacerbated by diuretics or other nephrotoxic drugs. May increase the hypoglycaemic effect of insulin and sulfonylureas in patients w/ DM. May increase toxic effects of ergot alkaloids and methotrexate. Potentially Fatal: Concurrent methoxyflurane may result to fatal renal toxicity. Increased risk of benign intracranial HTN w/ vit A or retinoids (e.g. acitretin,isotretinoin, tretinoin).

Adverse Effects

Side effects of Tetracycline Hydrochloride : >10% Discoloration of teeth and enamel hypoplasia (young children) 1-10% Diarrhea, Nausea, Photosensitivity <1% Anorexia, Abdominal cramps, Antibiotic-associated pseudomembranous colitis, Bulging fontanels in infants, Diabetes insipidus syndrome, Esophagitis, Exfoliative dermatitis, Incr ICP, Pericarditis, Pseudotumor cerebri, Pancreatitis, Pruritus, Pigmentation of nails, Vomiting Potentially Fatal: Anaphylaxis, hepatotoxicity, nephrotoxicity, blood dyscrasias.

Mechanism of Action

Tetracycline exhibits its bacteriostatic action by reversibly binding to the 30S subunits of the ribosome, thus preventing protein synthesis and arresting cell growth. It has a broad spectrum of antimicrobial activity including Chlamydiaceae, Mycoplasma spp., Rickettsia spp., spirochaetes, many aerobic and anaerobic gm+ve and gm-ve pathogenic bacteria and some protozoa.