Ethomid (Tablets) Instructions for Use

Marketing Authorization Holder

Macleods Pharmaceuticals Ltd. (India)

ATC Code

J04AD03 (Ethionamide)

Active Substance

Ethionamide (Rec.INN registered by WHO)

Dosage Form

Ethomid

Film-coated tablets, 250 mg: 50 and 100 pcs.

Dosage Form, Packaging, and Composition

10 pcs. – non-cell contour packs (10) – cardboard packs.

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 blood 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 with bile 70-80%, with 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 Ethomid orally in divided doses, following a gradual dose escalation to improve gastrointestinal tolerance.

For adults, initiate therapy at 250 mg once daily. After 5 days, increase the dose to 500 mg/day, administered in one or two divided doses. After another 5 days, increase to the full maintenance dose of 750 mg to 1 g per day.

The maximum daily dose for adults is 1 gram.

For pediatric patients, prescribe at a dose of 10-20 mg/kg of body weight per day. Do not exceed the maximum adult daily dose of 1 g. Divide the total daily dose into two or three administrations.

Adjust the dosage regimen for patients over 60 years of age and for those with a body weight below 50 kg.

Always use Ethomid in combination with other antituberculosis agents to prevent the development of resistance. Concurrently administer pyridoxine to help prevent peripheral neuritis.

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 for the respective age.

Geriatric Use

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

Special Precautions

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

Ethionamide is used only in combination with other antituberculosis drugs. 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 concomitant 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 regimen 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 25°C (77°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.