Myrin-P Forte Tablet

Myrin-P Forte Tablet is a prescription anti-tuberculosis medicine that combines four medicines—rifampicin, isoniazid, pyrazinamide, and ethambutol hydrochloride—in a single tablet. It is primarily used during the initial intensive phase of tuberculosis (TB) treatment. Combining the four anti-TB medicines in one tablet can simplify treatment while ensuring that the prescribed drugs are taken together.

Composition

Each Myrin-P Forte Tablet contains:

• Rifampicin: 150 mg
• Isoniazid:  75 mg
• Pyrazinamide: 400 mg
• Ethambutol hydrochloride: 275 mg

What is Myrin-P Forte used for?

Myrin-P Forte is used for the initial treatment of tuberculosis, including TB caused by susceptible Mycobacterium tuberculosis. It combines four important first-line anti-TB medicines that attack the tuberculosis bacteria through different mechanisms.

It may be prescribed as part of treatment for:

• Pulmonary tuberculosis (TB affecting the lungs)
• Certain forms of extrapulmonary tuberculosis
• The intensive phase of a standard TB treatment regimen

The exact regimen and duration depend on the type of TB, the patient’s weight, treatment history, drug susceptibility and applicable TB treatment guidelines.

How does Myrin-P Forte work?

The four ingredients work together against tuberculosis bacteria.

Rifampicin interferes with bacterial RNA production, while isoniazid disrupts the formation of the mycobacterial cell wall. Pyrazinamide has important activity against TB bacteria in particular environments within infected tissues, and ethambutol interferes with formation of components needed for the mycobacterial cell wall.

Using several effective anti-TB medicines together is important because tuberculosis should not normally be treated with a single active drug.

How to take Myrin-P Forte

Myrin-P Forte should be taken only under the supervision of a doctor experienced in treating tuberculosis. The number of tablets required is determined according to the patient’s body weight and treatment regimen; patients should not determine their own dose.

The tablets are generally taken as a single daily dose on an empty stomach, at least one hour before food, unless the treating healthcare professional provides different instructions.

Do not stop TB treatment early simply because you feel better. Missing doses or stopping treatment without medical advice can reduce the effectiveness of treatment and contribute to drug-resistant tuberculosis.

Common side effects

Side effects can vary because Myrin-P Forte contains four active medicines. Possible effects include:

• Nausea or vomiting
• Loss of appetite
• Abdominal discomfort
• Headache or dizziness
• Joint pain
• Increased uric acid levels
• Skin rash or itching
• Changes in liver function tests

Rifampicin can cause urine, sweat, saliva and tears to become orange or reddish. This discoloration can be expected during treatment, although patients should still discuss anything unusual with their healthcare professional.

Important warnings

Liver problems

Rifampicin, isoniazid and pyrazinamide can affect the liver. Contact your doctor promptly if you develop symptoms such as persistent nausea or vomiting, severe loss of appetite, unusual tiredness, yellowing of the skin or eyes, or dark urine.

Patients with existing liver disease or other risk factors may require closer monitoring.

Changes in eyesight

Ethambutol can rarely cause optic neuritis, which can affect visual sharpness and colour vision. Report blurred vision, reduced vision or difficulty distinguishing colours promptly. Visual assessment may be required before and during treatment, particularly when treatment is prolonged or risk factors are present.

Nerve problems

Isoniazid can cause peripheral neuropathy, which may present as tingling, numbness or burning sensations in the hands or feet. Doctors sometimes prescribe pyridoxine (vitamin B6) to patients at increased risk. Do not add supplements to the regimen without discussing them with your healthcare professional.

Drug interactions

Myrin-P Forte can have numerous clinically important drug interactions, particularly because rifampicin strongly affects the metabolism of many medicines.

Potentially affected medicines include certain:

• Anticoagulants
• Oral contraceptives
• Antiretroviral medicines
• Antifungal medicines
• Anti-seizure medicines
• Heart medicines
• Immunosuppressants
• Diabetes medicines

This is not a complete interaction list. A doctor or pharmacist should review the patient’s medicines before and during treatment.

Important Safety Information

Myrin-P Forte is a specialist anti-tuberculosis treatment, not a medicine for self-treatment. The dose and duration must be determined by a healthcare professional. Regular clinical assessment and, where appropriate, liver, vision and other monitoring may be required during treatment.