Class: Antituberculosis agent
- Tablets 250 mg
Inhibition of peptide synthesis in susceptible organisms is suspected.
Essentially completely absorbed.
Ethionamide is approximately 30% bound to plasma protein. It is widely distributed into tissues and fluids with significant concentrations found in cerebrospinal fluid. Concentrations approximating the therapeutic range are usually seen within 2 h following doses of 250 to 500 mg.
Ethionamide is extensively metabolized in the liver to active and inactive metabolites.
The plasma elimination t ½ is approximately 2 h. Less than 1% is excreted unchanged in the urine.
Indications and Usage
Treatment of tuberculosis, in combination with other agents, in patients with Mycobacterium tuberculosis resistant to isoniazid or rifampin, or when there is intolerance to other antituberculous agents.
Severe hepatic function impairment; hypersensitivity to any component of the product.
Dosage and AdministrationAdults
PO 15 to 20 mg/kg taken once daily (max, 1 g/day). To reduce GI intolerance, initiate therapy with 250 mg/day and titrate to optimal dose as tolerated (eg, 250 mg/day for 1 or 2 days, followed by 250 mg twice daily for 1 or 2 days, subsequently increasing the dose to 1 g in 3 or 4 divided doses).Children 12 yr of age and older
PO 10 to 20 mg/kg/day in 2 to 3 divided doses given after meals or 15 mg/kg every 24 h as a single daily dose.
Administer with or after meals to reduce GI adverse reactions.
Store tablets at controlled room temperature (59° to 86°F).
Drug InteractionsAntituberculous agents (eg, cycloserine)
Adverse reactions may be potentiated.Cycloserine
Risk of occurrence of adverse reactions or convulsions may be increased.Ethanol
Risk of occurrence of psychotic reactions may be increased.Isoniazid
Transient increases in isoniazid serum levels may occur.
Laboratory Test Interactions
None well documented.
Psychotic disturbances; depression; drowsiness; dizziness; headache; restlessness; peripheral neuritis.
Blurred vision; diplopia; optic neuritis.
Nausea; vomiting; diarrhea; abdominal pain; excessive salivation; metallic taste; stomatitis; anorexia.
Transient increases in serum bilirubin, AST and ALT; hepatitis (with or without jaundice).
Weight loss; hypoglycemia; difficulty in managing diabetes mellitus.
Postural hypotension; photosensitivity; pellagra-like syndrome.
Determine serum transaminases (ie, AST, ALT) prior to therapy and monthly during therapy; monitor blood glucose and perform ophthalmologic examinations prior to therapy and periodically during therapy.
Category C .
Safety and efficacy not established. Do not administer to patients younger than 12 yr of age unless organisms are definitely resistant to primary therapy and systemic dissemination of the disease, or other life-threatening complications or tuberculosis are judged imminent.
Use of ethionamide alone may result in rapid development of resistance.
- Review dosing schedule and prescribed length of therapy with patient.
- Emphasize to patient that treatment will be lengthy and that the entire course of treatment must be completed to avoid relapse or development of resistance.
- Advise patient to take each dose with food to prevent or reduce GI adverse reactions.
- Advise diabetic patient to monitor blood sugar throughout therapy and to be alert for episodes of hypoglycemia. Ensure that patient has a plan for treating hypoglycemic events should they occur and to inform health care provider should this occur.
- Instruct patient to report the following to health care provider: intolerable GI adverse reactions, changes in thinking or mood, dizziness, blurred vision or loss of vision, with or without eye pain.
- Advise patient that drug may cause drowsiness or dizziness and to use caution while driving or performing other tasks requiring mental alertness until tolerance is determined.
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