Side effects of ethionamide are manifested by the gastrointestinal tract, liver, skin, endocrine and nervous system.
From the gastrointestinal tract: loss of appetite, nausea, vomiting, dry mouth or hypersalivation, a "metallic" taste in the mouth. After the withdrawal of the drug, these phenomena tend to quickly pass.
Often during treatment there is an increase in activity of "liver" transaminases. Rare violations of liver function with signs of hepatitis and jaundice are rare. Hepatotoxicity of the drug depends on the existing violations of liver function, such as liver damage due to alcoholism or after surgery. These side effects are especially noted with combined therapy with isoniazid, rifampicin and pyrazinamide.
Skin reactions are rare, in some cases described pellagrope-like reactions in combination with violations from the central nervous system.
Sometimes there are violations of the endocrine system. Along with the development of hypoglycemia (a decrease in blood glucose less than 50 mg%) in patients with diabetes, described the development of gynecomastia (an increase in mammary glands in men). Rarely there is a violation of the menstrual cycle and impotence, as well as hypothyroidism (a decrease in thyroid function).
Ethionamide can sometimes cause disturbances in the peripheral and central nervous systems. The intake of ethionamide can cause dizziness, headaches, weakness, impaired concentration, mental disorders. Rarely, optic neuritis, tachycardia.