Myobid-250 (Tablets) Instructions for Use

Marketing Authorization Holder

Panacea Biotec, Ltd. (India)

ATC Code

J04AD03 (Ethionamide)

Active Substance

Ethionamide (Rec.INN registered by WHO)

Dosage Form

Myobid-250

Coated tablets, 250 mg: 50, 60, or 100 pcs.

Dosage Form, Packaging, and Composition

Coated tablets yellow in color, round, biconvex; on the break – a yellow core.

Excipients: microcrystalline cellulose, colloidal silicon dioxide, starch (corn), povidone (K-30), purified water, magnesium stearate, purified talc, sodium starch glycolate, croscarmellose sodium, dye Wincoat-WT-N-1505 (yellow), dichloromethane, isopropyl alcohol.

10 pcs. – blister packs (5) – cardboard boxes.
10 pcs. – blister packs (6) – cardboard boxes.
10 pcs. – blister packs (10) – cardboard boxes.

Clinical-Pharmacological Group

Antituberculosis drug

Pharmacotherapeutic Group

Antitubercular agent

Pharmacological Action

Second-line antituberculosis agent. The mechanism of action is not precisely known. Apparently, Ethionamide suppresses the synthesis of mycobacterial proteins. It has a bacteriostatic effect on Mycobacterium tuberculosis.

It enhances phagocytosis in the focus of tuberculous inflammation, which promotes its resorption. During treatment, the tuberculostatic activity of ethionamide decreases.

Pharmacokinetics

After oral administration, Ethionamide is rapidly absorbed from the gastrointestinal tract. At a dose of 250 mg, C_max in plasma is reached after 1-3 hours and is about 2 µg/ml. It is widely distributed in body tissues and fluids. It penetrates the placental barrier and intact meninges. In the cerebrospinal fluid, it is determined in concentrations equivalent to serum concentrations.

It is metabolized in the liver to form an active sulfoxide metabolite and inactive metabolites. It is excreted in bile 70-80%, in urine – 20-30% (less than 1% unchanged).

Indications

Pulmonary tuberculosis (in case of intolerance or ineffectiveness of other antituberculosis drugs).

ICD codes

Dosage Regimen

Administer this drug orally, exclusively in combination with other antituberculosis agents to prevent the development of resistance.

For adult initiation, prescribe an initial dose of 250 mg once daily.

After 5 days, increase the dose to 500 mg per day, administered in divided doses.

Following another 5 days, further increase the dose to a maximum of 1 g per day.

The maximum daily dose for adults is 1 gram; do not exceed this limit.

For pediatric patients, calculate the dose based on 10-20 mg per kg of body weight per day.

Divide the total daily dose for all patients into two to four separate administrations to improve gastrointestinal tolerance.

Administer doses with meals to minimize adverse gastrointestinal effects.

For patients over 60 years of age or those weighing less than 50 kg, a dose adjustment is required; use a lower or less frequently escalated regimen.

Concomitantly administer pyridoxine (Vitamin B6) to help prevent the development of peripheral neuropathy.

Adverse Reactions

From the digestive system: loss of appetite, nausea, vomiting, dry mouth or hypersalivation, metallic taste in the mouth, increased activity of hepatic transaminases; rarely – severe liver dysfunction with signs of hepatitis and jaundice.

From the nervous system: polyneuropathy, headache, dizziness, impaired concentration, mental disorders, optic neuritis.

From the cardiovascular system: orthostatic hypotension.

From the endocrine system: hypoglycemia, hypothyroidism, gynecomastia; rarely – menstrual irregularities, impotence, hypothyroidism.

Other: allergic reactions, pellagra-like reactions in combination with CNS disorders, weakness, tachycardia, bone marrow disorders.

Contraindications

Hypersensitivity to ethionamide; hepatic insufficiency, acute gastritis, gastric and duodenal ulcer, erosive-ulcerative colitis, acute hepatitis, liver cirrhosis, chronic alcoholism; pregnancy, breastfeeding period.

With caution

Diabetes mellitus, epilepsy.

Use in Pregnancy and Lactation

Contraindicated for use during pregnancy and breastfeeding.

Use in Hepatic Impairment

Contraindicated in hepatic insufficiency, acute hepatitis, liver cirrhosis.

Pediatric Use

Can be used in children according to indications, in doses and regimens recommended according to age.

Geriatric Use

In patients over 60 years of age, dose adjustment is required.

Special Precautions

Before starting therapy, the in vitro sensitivity of the Mycobacterium tuberculosis strain recently isolated from the patient to ethionamide should be investigated.

Ethionamide is used only in combination with other antituberculosis agents. The use of ethionamide in combination with prothionamide is not advisable, as Mycobacterium tuberculosis has cross-resistance to these agents.

Before using ethionamide and every 2-4 weeks of treatment, it is necessary to monitor the activity of liver transaminases. In case of combined use with pyrazinamide, more frequent than usual monitoring of liver function is necessary.

The hepatotoxicity of ethionamide depends on existing liver function disorders, such as liver damage due to alcoholism or after surgical interventions. These side effects are particularly common with combination therapy with isoniazid, rifampicin, and pyrazinamide.

Concomitant use of drugs with hepatotoxic effects should be avoided.

During ethionamide administration, pyridoxine is prescribed to prevent the development of peripheral neuritis.

In patients over 60 years of age and patients with a body weight of less than 50 kg, dose adjustment is required.

Alcohol consumption during ethionamide use leads to CNS depression.

Drug Interactions

During combination therapy for tuberculosis, the additive hepatotoxic effect of individual drugs should be taken into account. This especially applies to the combination of ethionamide with isoniazid, rifampicin, and pyrazinamide.

With simultaneous use of ethionamide and cycloserine, the risk of neurotoxic side effects increases (especially in patients with a history of neurological or mental disorders).

Concomitant use of other antituberculosis drugs that affect the CNS, such as isoniazid or cycloserine, as well as simultaneous alcohol consumption, may lead to an increase in CNS side effects.

With simultaneous use of ethionamide and oral hypoglycemic drugs, the hypoglycemic effect of the latter is enhanced.

Storage Conditions

Store at 2°C (36°F) to 30°C (86°F). Keep in original packaging, protected from light. Keep out of reach of children.

Dispensing Status

Rx Only

Important Safety Information

This information is for educational purposes only and does not replace professional medical advice. Always consult your doctor before use. Dosage and side effects may vary. Use only as prescribed.