FDA label 24a0b78d-6cf2-4539-a3de-b3b077383da0

WARNINGS The use of Trecator alone in the treatment of tuberculosis results in rapid development of resistance. It is essential, therefore, to give a suitable companion drug or drugs, the choice being based on the results of susceptibility testing. However, therapy may be initiated prior to receiving the results of susceptibility tests as deemed appropriate by the physician. Ethionamide should be administered with at least one, sometimes two, other drugs to which the organism is known to be susceptible (see INDICATIONS AND USAGE ). Drugs which have been used as companion agents are rifampin, ethambutol, pyrazinamide, cycloserine, kanamycin, streptomycin, and isoniazid. The usual warnings, precautions, and dosage regimens for these companion drugs should be observed. Patient compliance is essential to the success of the anti-tuberculosis therapy and to prevent the emergence of drug-resistant organisms. Therefore, patients should adhere to the drug regimen for the full duration of treatment. It is recommended that directly observed therapy be practiced when patients are receiving anti-tuberculous medication. Additional consultation from experts in the treatment of drug-resistant tuberculosis is recommended when patients develop drug-resistant organisms. Severe Cutaneous Adverse Reactions Cases of severe cutaneous adverse reactions (SCARs), such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS), and acute generalized exanthematous pustulosis (AGEP) have been reported with the use of combinations of anti-tuberculosis drugs that included ethionamide (see ADVERSE REACTIONS ). If symptoms or signs of SCARs develop, discontinue suspect drug(s) immediately and institute appropriate therapy.

ADVERSE REACTIONS Gastrointestinal The most common side effects of ethionamide are gastrointestinal disturbances including nausea, vomiting, diarrhea, abdominal pain, excessive salivation, metallic taste, stomatitis, anorexia and weight loss. Adverse gastrointestinal effects appear to be dose related, with approximately 50% of patients unable to tolerate 1 gm as a single dose. Gastrointestinal effects may be minimized by decreasing dosage, by changing the time of drug administration, or by the concurrent administration of an antiemetic agent. Nervous System Psychotic disturbances (including mental depression), drowsiness, dizziness, restlessness, headache, and postural hypotension have been reported with ethionamide. Rare reports of peripheral neuritis, optic neuritis, diplopia, blurred vision, and a pellagra-like syndrome also have been reported. Concurrent administration of pyridoxine has been recommended to prevent or relieve neurotoxic effects. Hepatic Transient increases in serum bilirubin, SGOT, SGPT; Hepatitis (with or without jaundice). Other Hypersensitivity reactions including rash, photosensitivity, thrombocytopenia and purpura have been reported rarely. Hypoglycemia, hypothyroidism, gynecomastia, impotence, and acne also have occurred. The management of patients with diabetes mellitus may become more difficult in those receiving ethionamide. Immune System Disorders: SCARs such as SJS, TEN, DRESS, and AGEP have been reported with the use of combinations of anti-tuberculosis drugs that included ethionamide (see WARNINGS ).