Ethionamide is used with other medications to treat tuberculosis (TB). Ethionamide is an antibiotic and works by stopping the growth of bacteria.

This antibiotic treats only bacterial infections. It will not work for viral infections (such as common cold, flu). Using any antibiotic when it is not needed can cause it to not work for future infections.

This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.

This drug may also be used for a certain serious infection (Mycobacterium avium complex-MAC).

Take this medication by mouth with or without food as directed by your doctor, usually once daily. If this medication causes stomach upset or nausea/vomiting, take this medication with meals. Also, discuss with your doctor if it may be helpful to divide your daily dose into smaller doses to be taken several times a day. Follow your doctor's instructions carefully.

The dosage is based on your age, weight, medical condition, and response to treatment.

For the best effect, take this antibiotic at evenly spaced times. To help you remember, take this medication at the same time(s) every day.

Continue to take this medication (and other TB medications) until the full prescribed amount is finished, even if symptoms disappear. Stopping the medication too early or skipping doses may result in a return of the infection and cause the infection to be more difficult to treat (resistant).

Your doctor may also direct you to take vitamin B6 (pyridoxine) to help prevent certain side effects (such as nerve problems) from ethionamide. Follow your doctor's instructions carefully.

Tell your doctor if your condition lasts or gets worse.

Nausea, vomiting, diarrhea, abdominal/stomach pain, increased saliva, strange metallic taste in the mouth, loss of appetite, or sores in the mouth may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Many people using this medication may have serious side effects. However, you have been prescribed this drug because your doctor has judged that the benefit to you is greater than the risk of side effects. Careful monitoring by your doctor may decrease your risk.

Tell your doctor right away if you have any serious side effects, including:

• nausea/vomiting that doesn't stop
• unusual hunger
• unusual sweating
• shakiness
• unusual tiredness/weakness
• yellowing eyes/skin
• dark urine
• joint pain/swelling
• slow heartbeat
• mental/mood changes (such as nervousness, restlessness, depression)
• vision changes (such as blurred/decreased/double vision, color blindness)
• eye pain
• numbness/tingling of arms/legs

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• fever that doesn't go away
• new or worsening lymph node swelling
• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking ethionamide, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• liver disease
• kidney disease
• underactive thyroid (hypothyroidism)
• eye problems (such as optic neuritis, cataracts, diabetic retinopathy)

Alcohol may increase the risk of liver disease or mental/mood changes. Avoid alcoholic beverages while using this medication.

Ethionamide may cause live bacterial vaccines (such as typhoid vaccine) to not work well. Tell your health care professional that you are using ethionamide before having any immunizations/vaccinations.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

If you have diabetes, this product may lower your blood sugar. Check your blood sugar regularly as directed and share the results with your doctor. Tell your doctor right away if you have symptoms of low blood sugar, such as sudden sweating, shaking, fast heartbeat, hunger, blurred vision, dizziness, or tingling hands/feet. Your doctor may need to adjust your diabetes medication, exercise program, or diet.

Tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while using ethionamide. Ethionamide may harm an unborn baby. If you become pregnant, talk to your doctor right away about the risks and benefits of this medication.

It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

Lab and/or medical tests (such as sputum test, eye/vision exams, liver/thyroid function, blood glucose, complete blood count) should be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

It is important to take each dose of this medication as scheduled. If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.