Minocin

• Routine antibiotic use: 200 mg daily in divided doses
• Acne: 50 mg twice daily for at least 6 weeks.
• Gonorrhoea: Males: 200 mg initially followed by 100 mg every 12 hours for a minimum of 4 days. Post therapy cultures within 2-3 days. Females: May require a more prolonged therapy.
• Prophylaxis of asymptomatic meningococcal carriers: 100 mg twice daily for 5 days, followed by treatment with rifampicin.

If, after six months, there is no satisfactory response minocycline should be discontinued and other therapies considered. If minocycline is to be continued for longer than six months, patients should be monitored at least three monthly intervals thereafter for signs and symptoms of hepatitis or SLE.

Reported side effects are oral and anogenital candidiasis, vulvovaginitis, eosinophilia, leucopenia, neutropenia, thrombocytopenia, haemolytic anaemia, pancytopenia, agranulocytosis, anaphylaxis, anaphylactoid reaction, hypersensitivity, pulmonary infiltrates, anaphylactoid purpura, polyarthritisnodosa, abnormal thyroid function, brown-black discolouration of the thyroid, anorexia, dizziness, headache, hypaesthesia, paraesthesia, intracranial hypertension, vertigo, Bulging fontanelle, convulsions, sedation, impaired hearing, tinnitus, myocarditis, pericarditis, cough, dyspnoea, bronchospasm, exacerbation of asthma, pulmonary eosinophilia, pneumonitis, diarrhoea, nausea, stomatitis, discolouration of teeth, vomiting, dyspepsia, dysphagia, enamel hypoplasia, enterocolitis, oesophagitis, oesophageal ulceration, glossitis, pancreatitis, pseudomembranous colitis, increased liver enzymes, hepatitis, autoimmune hepatotoxicity, hepatic cholestatis, hepatic failure, hyperbilirubinemia, jaundice, autoimmune hepatitis, alopecia, erythema multiforme, erythema nodosum, fixed drug eruption, hyperpigmentation of the skin, photosensitivity, pruritis, rash, urticaria, vasculitis, angioedema, exfoliative dermatitis, hyperpigmentation of nails, Stevens-Johnson syndrome, toxic epidermal necrolysis, Drug reaction with eosinophilia and systemic symptoms (DRESS), arthralgia, lupus-like syndrome, myalgia, arthritis, bone discolouration, cases of systemic lupus erythematous (SLE), joint stiffness, joint swelling, increased serum urea, acute renal failure, interstitial nephritis, balanitis, fever, etc. In some cases involving these syndromes, death has been reported.

Hyperpigmentation of various body sites including the skin, nails, teeth, oral mucosa, bones, thyroid, eyes (including sclera and conjunctiva), breast milk, lacrimal secretions and perspiration has been reported. This blue/black/grey or muddy-brown discolouration may be localised or diffuse. The most frequently reported site is in the skin. Pigmentation is often reversible on discontinuation of the drug, although it may take several months or may persist in some cases. The generalised muddy-brown skin pigmentation may persist, particularly in areas exposed to the sun.

Dizziness, nausea and vomiting are the adverse effects most commonly seen in overdose. Gastric lavage plus appropriate supportive treatment. Antacids and calcium salts will reduce absorption of minocycline but there is no specific antidote. Minocycline is not removed in significant quantities by haemodialysis or peritoneal dialysis.

Breathing difficulties: Cases of breathing difficulties including dyspnoea, bronchospasm, exacerbation of asthma, pulmonary eosinophilia and pneumonitis have been reported with minocycline use. If patients develop breathing difficulties they should seek urgent medical advice and minocycline should be discontinued.

Paediatric population: All tetracyclines form a stable calcium complex in any bone forming tissue. An increase in the fibula growth rate has been observed in premature babies administered oral tetracyclines. Tetracyclines are known to cause a yellow to brown discoloration of the teeth and enamel hypoplasia in the developing child or foetus.

Hepatic impairment: Minocycline should be used with caution in patients with hepatic dysfunction or in conjunction with potentially hepatotoxic drugs, including alcohol.

Auto-immune disorders: Rare cases of auto-immune hepatotoxicity and isolated cases of systemic lupus erythematosus (SLE) have been reported. If patients develop signs or symptoms of SLE or hepatotoxicity, minocycline should be discontinued.

Renal impairment: Studies indicate there is no significant drug accumulation in patients with mild to moderate renal impairment when treated with the recommended dosages of minocycline. In cases of severe renal impairment a reduction of dosage and monitoring of renal function may be required.

Cross-sensitivities: Micro-organisms can develop cross resistance to tetracyclines and patients can develop cross sensitivity. Minocycline should be discontinued there are signs/symptoms of overgrowth of resistant organisms.

Intracranial hypertension: As with other tetracyclines, bulging fontanelles in infants and benign intracranial hypertension in juveniles and adults have been reported. Presenting features were headache and visual disturbances including blurring of vision, scotoma and diplopia. Permanent vision loss has been reported. Treatment should cease if evidence of raised intracranial pressure develops.

Hyperpigmentation: As with other tetracyclines, minocycline may cause hyperpigmentation at various body sites. Hyperpigmentation may present regardless of dose or duration of therapy but develops more commonly during long term treatment. Patients should be advised to report any unusual pigmentation without delay and minocycline should be discontinued.

Photosensitivity: Tetracyclines are known to cause photosensitivity reactions. Such patients should be warned to avoid direct exposure to natural or artificial sunlight and to discontinue therapy at the first sign of skin discomfort.

Tetracycline group of drugs