Myconil 450 mg Capsule

Rifamycin antibiotic for:

• Tuberculosis (always in combination with other anti-TB drugs)
• Leprosy (multidrug therapy)
• Prevention of meningococcal and Haemophilus influenzae type b infection in close contacts
• Serious staphylococcal infections (with another antibiotic), brucellosis, Legionella (specialist)

Tuberculosis (adults and children): 10 mg/kg once daily (adults: 450 mg if < 50 kg, 600 mg if ≥ 50 kg) — as part of combination therapy, usually 6 months.

Leprosy: 600 mg once monthly (supervised) with other drugs.

Meningococcal prophylaxis: adults 600 mg twice daily for 2 days; children 10 mg/kg (infants < 1 month: 5 mg/kg) twice daily for 2 days.

• Take on an empty stomach (30–60 minutes before or 2 hours after food).
• Do not stop TB treatment early; take every day.

• Jaundice/active liver disease
• Allergy to rifamycins
• Use with certain HIV protease inhibitors (e.g. saquinavir/ritonavir), and some other drugs (see interactions)

Common: orange-red urine, sweat, tears, saliva (harmless; stains contact lenses), nausea, loss of appetite, abdominal discomfort, raised liver enzymes.

Serious: liver injury (hepatitis), flu-like syndrome with intermittent dosing, low platelets with bruising/bleeding, haemolytic anaemia, kidney injury, severe skin reactions, shortness of breath/shock (rare).

• Liver tests before and during treatment (especially with alcohol use, liver disease, elderly).
• Stop and seek help with jaundice, dark urine, vomiting, bruising or bleeding.
• Hormonal contraception becomes unreliable — use another method.
• Avoid alcohol.
• Restarting after a break may cause hypersensitivity reactions.

Used in pregnancy for TB (benefit outweighs risk); give vitamin K to mother and newborn if used in late pregnancy. Compatible with breastfeeding.

Strong enzyme inducer — reduces the effect of many medicines:

• Oral contraceptives, warfarin, DOACs (rivaroxaban, apixaban), steroids, antiretrovirals (protease inhibitors, nevirapine, dolutegravir), azole antifungals, methadone and other opioids, sulphonylureas, calcium-channel blockers, statins, digoxin, ciclosporin, tacrolimus, antiepileptics, levothyroxine, haloperidol
• Antacids (take 1 hour apart)
• Paracetamol, alcohol, isoniazid (liver toxicity)

Nausea, vomiting, abdominal pain, red-orange skin colour ("red man"), itching, liver injury, seizures. Emergency care.

Store below 30°C, protected from light and moisture.