Myconil

Indications

• Tuberculosis (TB), always together with other TB medicines such as Isoniazid, Pyrazinamide and Ethambutol
• Leprosy, together with other medicines such as Dapsone and Clofazimine
• Preventing meningococcal infection in close contacts of a patient
• Some serious bacterial infections (such as certain staphylococcal infections and brucellosis), always combined with another antibiotic, as decided by a doctor

How It Works

Rifampicin is an antibiotic of the rifamycin group. It blocks an enzyme (RNA polymerase) that bacteria need to make proteins, which kills them. Using it with other medicines prevents the bacteria becoming resistant.

Dosage and Administration

Tuberculosis: given as prescribed, usually under the national TB programme. The usual daily dose is about 10 mg per kg of body weight once a day; for adults this is commonly 450 mg for those under 50 kg and 600 mg for those 50 kg and over, often as a combination tablet. Children are dosed by weight as prescribed. Leprosy, meningococcal prevention and other infections: as prescribed.

• Take on an empty stomach, at least 30 minutes before breakfast or 2 hours after a meal, with a glass of water.
• Take it every day for the full course (usually 6 months or more for TB), even when you feel well. Missing doses can make TB harder to treat.

Interactions

Rifampicin speeds up the breakdown of many medicines and can make them stop working. Important examples:

• Hormonal contraceptives (pills, implants, injections): they become unreliable; use condoms or a copper coil during treatment and for 4 weeks after.
• Warfarin, diabetes medicines, Prednisolone and other steroids, Methadone, Digoxin, Phenytoin, Carbamazepine, Ciclosporin, Tacrolimus, azole antifungals such as Fluconazole, and many HIV medicines.
• Antacids reduce its absorption; take them at least 1 hour apart.

Always tell every doctor, dentist and pharmacist that you take rifampicin.

Contraindications

• Allergy to rifampicin or other rifamycins
• Jaundice (yellow skin or eyes)
• Use together with Saquinavir and Ritonavir, or certain other HIV protease inhibitors

Side Effects

Rifampicin turns urine, sweat, tears and saliva orange-red; this is harmless but can permanently stain soft contact lenses and clothes. Other common effects: nausea, loss of appetite, heartburn, stomach cramps, diarrhoea, itching or rash, and flu-like symptoms (fever, chills, aches), especially if doses are missed or taken irregularly.

Get urgent medical help for yellow skin or eyes, persistent vomiting, severe tiredness or pain in the upper right belly (possible liver damage); unusual bleeding or bruising or small purple spots on the skin; a severe rash with blisters or peeling; breathlessness or wheezing; passing much less urine; or severe watery or bloody diarrhoea.

Pregnancy and Lactation

TB in pregnancy must be treated, and rifampicin is part of standard treatment under a doctor. If used in the last weeks of pregnancy, vitamin K may be given to the mother and the newborn to prevent bleeding. Small amounts pass into breast milk; breastfeeding can usually continue, but tell your doctor.

Precautions and Warnings

• Liver blood tests are usually checked before and during treatment, especially in people with liver disease, heavy alcohol use or older age. Avoid alcohol.
• Do not stop or interrupt treatment without your doctor, as this can cause resistance and, on restarting, serious reactions.
• People with diabetes may find their sugar harder to control.
• Tell your doctor if you have porphyria.

Overdose

Signs include nausea, vomiting, stomach pain, itching, orange-red skin, drowsiness and, in severe cases, liver damage or fits. Seek medical help immediately.

Therapeutic Class

Rifamycin antibiotic (anti-tuberculosis and anti-leprosy medicine).

Storage

Store below 30°C in a dry place, away from light and out of the reach of children. Shake the syrup well before use.