Ethionamide

Dosage Forms & Strengths

tablet

• 250mg

Tuberculosis, Active

15-20 mg/kg/day PO 

Initiate dose at 250 mg/day for 1-2 days; THEN increase to 250 mg twice daily for 1-2 days with gradual increases to highest tolerated dose; 750 mg/day average dose

Not to exceed 1000 mg/day in 3-4 divided doses

Renal Impairment

End-stage renal disease on hemodialysis: 250-500 mg/day

CrCl <30 mL/min: 250-500 mg/day

CrCl ≥ 30 mL/min: No dose adjustment necessary

Administration

Part of multi-drug regimen; not first-line treatment

Take with food

Dosing Considerations

If susceptibility tests indicate that the patient's organism is resistant to one of first-line antituberculosis drugs (i.e., isoniazid or rifampin) yet susceptible to ethionamide, ethionamide should be accompanied by at least one drug to which M. tuberculosis isolate is known to be susceptible;3 if tuberculosis is resistant to both isoniazid and rifampin, yet susceptible to ethionamide, ethionamide should be accompanied by at least two other drugs to which the M. tuberculosis isolate is known to be susceptible

Directly observed therapy is recommended for all patients receiving treatment for tuberculosis

Monitor: baseline & periodic LFTs, TFTs, glucose

Dosage Forms & Strengths

tablet

• 250mg

Tuberculosis, Active

M. tuberculosis resistant to isoniazid or rifampin, or patient intolerant to drugs

10-20 mg/kg/day divided BID/TID PO OR 

15 mg/kg PO qDay

No more than 1000 mg/day in 3-4 divided doses

Administration

Part of multi-drug regimen; not first-line treatment

Take after meals

Dosing Considerations

If susceptibility tests indicate that the patient's organism is resistant to one of first-line antituberculosis drugs (i.e., isoniazid or rifampin) yet susceptible to ethionamide, ethionamide should be accompanied by at least one drug to which M. tuberculosis isolate is known to be susceptible; if tuberculosis is resistant to both isoniazid and rifampin, yet susceptible to ethionamide, ethionamide should be accompanied by at least two other drugs to which the M. tuberculosis isolate is known to be susceptible

Directly observed therapy is recommended for all patients receiving treatment for tuberculosis

Monitor: baseline & periodic LFTs, TFTs, glucose

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

• numbness, tingling, or burning pain in your hands or feet;
• confusion; unusual thoughts or behavior;
• eye pain, blurred vision, double vision;
• a light-headed feeling, like you might pass out;
• seizure (convulsions); or
• upper stomach pain, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Common side effects may include:

• nausea, vomiting, diarrhea;
• stomach pain, loss of appetite;
• increased salivation, metallic taste in your mouth;
• blisters or ulcers in your mouth, red or swollen gums, trouble swallowing;
• headache, dizziness; or
• drowsiness, depressed mood, restless feeling.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

You should not use ethionamide if you have severe liver disease.

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

Avoid drinking alcohol while taking ethionamide.

Specific Drugs

Storage

Oral

20–25°C in a tight container.127

• Advise patients that poor compliance with antituberculosis regimens can result in treatment failure and development of drug-resistant TB, which can be life-threatening and lead to other serious health risks.106 127

• Importance of completing full course of therapy; importance of not missing any doses.127

• Importance of informing clinicians of any change in visual acuity (with or without eye pain).127

• Importance of avoiding excessive alcohol consumption.127

• Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs, as well as any concomitant illnesses.127

• Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.127

• Importance of informing patients of other important precautionary information.127 (See Cautions.)

Use this medicine as ordered by your doctor. Read all information given to you. Follow all instructions closely.

• Take with or without food. Take with food if it causes an upset stomach.
• If you have upset stomach, throwing up, loose stools (diarrhea), or are not hungry, talk with your doctor. There may be ways to lower these side effects.
• To gain the most benefit, do not miss doses.
• Keep taking ethionamide as you have been told by your doctor or other health care provider, even if you feel well.
• Take vitamin B6 (pyridoxine) as you were told by your doctor.

What do I do if I miss a dose?

• Take a missed dose as soon as you think about it.
• If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
• Do not take 2 doses at the same time or extra doses.

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Signs of liver problems like dark urine, feeling tired, not hungry, upset stomach or stomach pain, light-colored stools, throwing up, or yellow skin or eyes.
• Signs of low thyroid levels like hard stools (constipation); not able to handle cold; memory problems; mood changes; or a burning, numbness, or tingling feeling that is not normal.
• Lump on your neck.
• Low mood (depression).
• Mental, mood, or behavior changes that are new or worse.
• Change in eyesight, eye pain, or very bad eye irritation.
• Loss of eyesight.
• Very bad dizziness or passing out.
• Low blood sugar may occur. Signs may be dizziness, headache, feeling sleepy, feeling weak, shaking, a fast heartbeat, confusion, hunger, or sweating. Call the doctor right away if any of these signs occur. Follow what you have been told to do if low blood sugar occurs. This may include taking glucose tablets, liquid glucose, or some fruit juices.

Directly observed therapy (DOT) is recommended. Neurotoxic effects may be prevented or relieved by the coadministration of pyridoxine (see Pyridoxine monograph for dosing). Administer with or without meals. Gastrointestinal adverse effects may be decreased by administration at meals or bedtime, decreased dose, or giving with antiemetics.

Alcohol (Ethyl): May enhance the adverse/toxic effect of Ethionamide. Specifically, there may be a risk for a psychotic episode/reaction. Monitor therapy

BCG (Intravesical): Antibiotics may diminish the therapeutic effect of BCG (Intravesical). Avoid combination

BCG Vaccine (Immunization): Antibiotics may diminish the therapeutic effect of BCG Vaccine (Immunization). Monitor therapy

Cholera Vaccine: Antibiotics may diminish the therapeutic effect of Cholera Vaccine. Avoid combination

CycloSERINE: Ethionamide may enhance the adverse/toxic effect of CycloSERINE. Monitor therapy

Isoniazid: Ethionamide may increase the serum concentration of Isoniazid. Monitor therapy

Lactobacillus and Estriol: Antibiotics may diminish the therapeutic effect of Lactobacillus and Estriol. Monitor therapy

Sodium Picosulfate: Antibiotics may diminish the therapeutic effect of Sodium Picosulfate. Management: Consider using an alternative product for bowel cleansing prior to a colonoscopy in patients who have recently used or are concurrently using an antibiotic. Consider therapy modification

Typhoid Vaccine: Antibiotics may diminish the therapeutic effect of Typhoid Vaccine. Only the live attenuated Ty21a strain is affected. Management: Vaccination with live attenuated typhoid vaccine (Ty21a) should be avoided in patients being treated with systemic antibacterial agents. Use of this vaccine should be postponed until at least 3 days after cessation of antibacterial agents. Consider therapy modification

Applies to ethionamide: oral tablet

Along with its needed effects, ethionamide may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking ethionamide:

• Clumsiness or unsteadiness
• confusion
• mental depression
• numbness, tingling, burning, or pain in the hands and feet
• yellow eyes or skin

• Blindness or vision changes
• blue-yellow color blindness
• blurred vision or loss of vision, with or without eye pain
• burning, crawling, itching, numbness, painful, prickling, "pins and needles", or tingling feelings
• changes in menstrual periods
• coldness
• decreased sexual ability (in males)
• decreased vision
• difficulty in concentrating
• dry, puffy skin
• fast heartbeat
• fever
• hives, itching, or rash
• hoarseness
• increased hunger
• increased sensitivity of the skin to sunlight
• irritation
• joint pain, stiffness, or swelling
• redness or other discoloration of the skin
• severe sunburn
• shakiness
• swelling of the eyelids, face, lips, hands, or feet
• swelling of the front part of the neck
• tightness in the chest
• troubled breathing or swallowing
• weakness in the hands or feet
• weight gain

• Chills
• cold sweats
• coma
• cool, pale skin
• dark urine
• dizziness
• general tiredness and weakness
• headache
• light-colored stools
• nausea and vomiting
• nightmares
• seizures
• slurred speech
• unusual tiredness or weakness
• upper right abdominal or stomach pain
• yellow eyes and skin

Some side effects of ethionamide may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

• Abdominal or stomach pain
• diarrhea
• increased watering of the mouth
• loss of appetite
• metallic taste
• swelling or inflammation of the mouth
• weight loss

• Blemishes on the skin
• decreased interest in sexual intercourse
• enlargement of the breasts (in males)
• inability to have or keep an erection
• loss in sexual ability, desire, drive, or performance
• pimples