Oxytetracycline is primarily a bacteriostatic broad-spectrum antibiotic, which has a wide spectrum of activity against Gram-positive and Gram-negative microorganisms. Usually Oxytetracycline acts as an antimicrobial agent by inhibiting the protein synthesis of bacteria. It is also very effective against parasites such as rickettsia, mycoplasma, chlamydia and amoeba etc.

Pharmacology

Oxytetracycline inhibits cell growth by inhibiting translation. It binds to the 30S ribosomal subunit and prevents the amino-acyl tRNA from binding to the A site of the ribosome. The binding is reversible in nature. Oxytetracycline is lipophilic and can easily pass through the cell membrane or passively diffuses through porin channels in the bacterial membrane.

Oxytetracycline is indicated in-

• Respiratory tract infections
• Mycoplasma pneumonia
• Urinary tract infections
• Sexually transmitted diseases: Infections due to Chlamydia trachomatis including uncom-plicated urethral, endocervical or rectal infections, non gonococcal urethritis, chancroid, granuloma inguinale, lymphogranuloma venereum, gonorrhoea, syphilis
• Skin infections: Acne and rosacea
• Ophthalmic infections: Trachoma
• Rickettsial infections
• Other infections: Psittacosis, brucellosis, cholera, acute
• intestinal amoebiasis etc.

Adults: 250-500 mg every 6 hours. Food, milk and some dairy products interfere with the absorption of Tetracyclines. So Tetracyclines should be given one hour before or two hours after meals.

Oxytetracycline should not be used with patients who are hypersensitive to Tetracyclines. It should not be used in children under 12 years of age. It is contraindicated in pregnant women because of tooth staining in the fetus and possible growth retardation effects.

Side effects of Oxytetracycline, which have been reported in some patients, are anorexia, nausea, vomiting, diarrhoea, glossitis, skin rashes and urticaria.

Oxytetracycline should be used with caution in renal impairment.

Pregnancy & Lactation

Results of animal studies indicate that tetracyclines cross the placenta, are found in fetal tissues and can have toxic effects on the developing fetus. Evidence of embryotoxicity has also been noted in animals treated early in pregnancy. Tetracyclines are present in the milk of lactating women who are taking a drug in this class.