Oxytetracycline
Indications
Oxytetracycline is used for:
Acne, Susceptible infections, Uncomplicated gonorrhoea
Adult Dose
Oral
Susceptible infections
Adult: 250-500 mg 4 times daily. Max 4 g daily.
Acne
Adult: 250-500 mg bid.
Uncomplicated gonorrhoea
Adult: 1.5 g initially, followed by 0.5 g four times daily up to a total of 9 g per treatment course.
Intramuscular
Susceptible infections
Adult: 250 mg once daily or 300 mg daily in 2-3 divided doses.
Child Dose
Oral
Susceptible infections
Child: >8 yr: 25-50 mg/kg daily in 4 divided doses.
Intramuscular
Susceptible infections
Child: >8 yr: 15-25 mg/kg (max 250 mg) daily in 2-3 divided doses.
Renal Dose
Renal impairment: Dosage may need to be reduced.
Administration
Should be taken on an empty stomach. Take on an empty stomach 1 hr before or 2 hr after meals.
Contra Indications
Hypersensitivity to tetracyclines, children <8 yr, renal damage. Pregnancy, lactation.
Precautions
Elderly, renal or hepatic impairment; myasthenia gravis; lupus erythematosus, children <12 yr.
Pregnancy-Lactation
Interactions
Antacids, iron, aluminum, calcium, magnesium, zinc salts reduce absorption. Concurrent use may cause increased levels of lithium, digoxin, halofantrine and theophylline; decreased concentrations of atovaquone. Increased risk of ergotism with ergot alkaloids. May cause failure of oral contraception.
Potentially Fatal: Interferes with anticoagulant control. Nephrotoxic effects exacerbated by diuretics, methoxyflurane or other nephrotoxic drugs; avoid concurrent use with potentially hepatotoxic drugs. Increased incidence of benign intracranial hypertension with retinoids.
Adverse Effects
Side effects of Oxytetracycline :
Anorexia, nausea, vomiting, diarrhoea, glossitis, dysphagia, photosensitivity, oesphageal irritation and ulceration, nephrotoxicity, enterocolitis, rash (rare), blood dyscrasias. Headache, visual disturbances; intracranial hypertension; bulging fontanelles (infants).
Potentially Fatal: Rare. Fulminant diarrhoea in post operative patients.
Mechanism of Action
Oxytetracycline binds reversibly to the 30S and possibly 50S ribosomal subunits, thus inhibiting bacterial protein synthesis and arresting cell growth. It is active against a wide range of gram-positive and gram-negative organisms.