BMA Concise Guide to Medicine & Drugs

Minocycline

Brand names Aknemin, Minocin MR, Sebomin MR

Used in the following combined preparations None

QUICK REFERENCE

Drug group Tetracycline antibiotic

Overdose danger rating Low

Dependence rating Low

Prescription needed Yes

Available as generic Yes

GENERAL INFORMATION

Minocycline is a tetracycline antibiotic but has a longer duration of action than tetracycline itself. The drug is most commonly used to treat acne. It may also be given to treat pneumonia or to prevent infection in people with chronic bronchitis, and to treat sexually transmitted infections such as gonorrhoea and non-gonococcal urethritis. Minocycline is also used to treat chronic gum disease in adults. The drug’s most frequent side effects are nausea, vomiting, and diarrhoea. It also interferes with the balance mechanism in the ear, with resultant nausea, dizziness, and unsteadiness, but these generally disappear after the drug is stopped. Minocycline is safer to use than other tetracyclines in people with poor kidney function.

INFORMATION FOR USERS

Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Tablets, capsules, MR capsules, gel.

Frequency and timing of doses 1–2 x daily.

Dosage range Adults 100–200mg daily. Children Reduced dose according to age and weight.

Onset of effect 4–12 hours.

Duration of action Up to 24 hours.

Diet advice Milk products may impair absorption; avoid from 1 hour before to 2 hours after dosage.

Storage Keep in original container at room temperature out of the reach of children.

Missed dose Take as soon as you remember. If your next dose is due within 4 hours, take a single dose now and skip the next.

Stopping the drug Use the full course. Even if you feel better, the original infection may still be present and symptoms may recur if treatment is stopped too soon.

Exceeding the dose An occasional unintentional extra dose is unlikely to be a cause for concern. But if you notice any unusual symptoms, or if a large overdose has been taken, notify your doctor.

POSSIBLE ADVERSE EFFECTS

Minocycline may occasionally cause nausea, vomiting, or diarrhoea. Other, less common adverse effects include rashes, itching, increased sensitivity of the skin to sunlight, headache, blurred vision, and, in some cases, dizziness and vertigo. If any of these less common effects occur, stop taking the drug and consult your doctor promptly. Long-term use may occasionally cause additional effects (see Prolonged use).

INTERACTIONS

Oral anticoagulants Minocycline may increase the anticoagulant action of these drugs.

Retinoids Taken with minocycline these drugs may increase the risk of benign intracranial hypertension (high pressure in the skull) leading to headaches, nausea, and vomiting.

Oral contraceptives Minocycline can reduce the effectiveness of these drugs.

Penicillin antibiotics Minocycline interferes with the antibacterial action of these drugs.

Iron may interfere with the absorption of minocycline and may reduce its effectiveness.

Antacids, zinc preparations, and milk interfere with absorption of minocycline and may reduce its effectiveness. Doses should be separated by 1–2 hours.

Strontium ranelate may reduce the absorption of minocycline. The two drugs should not be used together.

SPECIAL PRECAUTIONS

Be sure to tell your doctor if:

· You have liver or kidney problems.

· You have previously suffered an allergic reaction to a tetracycline antibiotic.

· You have myasthenia gravis, acute porphyria, or systemic lupus erythematosus.

· You are taking other medicines.

Pregnancy Not prescribed. May cause birth defects and may damage the teeth and bones of the developing baby, as well as the mother’s liver. Discuss with your doctor.

Breast-feeding Not recommended. The drug passes into the breast milk and may damage developing bones and discolour the baby’s teeth. Discuss with your doctor.

Infants and children Not recommended under 12 years. Reduced dose necessary in older children. May discolour developing teeth.

Over 60 No special problems.

Driving and hazardous work Avoid such activities until you have learned how minocycline affects you because the drug can cause dizziness.

Alcohol No known problems.

How to take your tablets To prevent minocycline from sticking in your throat, a small amount of water should be taken before, and a full glass of water taken after, each dose. Take this medication while sitting or standing and do not lie down immediately afterwards.

PROLONGED USE

Prolonged use may occasionally cause skin darkening and discoloration of the teeth. Very rarely, it may cause systemic lupus erythematosus.

Monitoring Regular blood tests should be carried out to assess liver function, especially if treatment lasts over 6 months.