Indications
Tetracycline ointment is indicated as followings-
- Treatment of bacterial conjunctivitis
- Treatment of trachoma (by preference use oral azithromycin for this indication)
- Prevention of chlamydial and gonococcal neonatal conjunctivitis
Pharmacology
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.
Dosage And Administration
Wash the eyes with boiled and cooled water before each application. Use sterile sodium chloride 0.9% for newborns. Apply tetracycline 1% into the conjunctival sac of both eyes:
- Conjunctivitis: one application 2 times daily for 7 days
- Trachoma: one application 2 times daily for 6 weeks
- Prevention of neonatal conjunctivitis: one single application immediately after birth
Interaction
Impaired absorption with 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 with 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 with DM. May increase toxic effects of ergot alkaloids and methotrexate.
Contraindications
Do not use in patients with hypersensitivity to tetracyclines. May cause allergic reactions; stop treatment in the event of a serious reaction.
Side Effects
Burning, irritation, visual disturbances, superinfections, photosensitivity, hypersensitivity.
Pregnancy And Lactation
Pregnancy Category- D. There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.
Precautions And Warnings
Hepatic impairment. Avoid exposure to sunlight. Periodic evaluation of renal, hepatic and haematological system during prolonged therapy.
Therapeutic Class
Ophthalmic antibacterial drugs.
Storage Conditions
Store below 25°C. Keep out of the reach of children. Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing. Do not keep outdated medicine or medicine no longer needed.