其他名称：硫异烟胺
性状：肠溶片。
功能主治：常与其他抗结核病药联合应用，以增强疗效和避免病菌产生耐药性。
用法及用量：１日量0.5-0.8g，１次服用或分次服（以１次服效果为好）。必要时也可从小剂量（每日0.3g）开始。
不良反应和注意：服药后有恶心、呕吐、腹痛、腹泻、厌食、胃部不适等症状，多于服药２～３周后发生。如不能耐受，可酌减剂量或暂停服药，俟症状消失后继续服用。如合用碳酸氢钠，或服肠溶片，可减轻反应。在发生呕吐时，可同时使用止吐药物。少数病人有糙皮病症状、精神抑郁、视力紊乱和头痛、末梢神经炎、经期紊乱、男性乳房女性化、脱发、关节痛、皮疹、痤疮等。
规格：肠溶片：每片0.1g。
其它：对20-30%病人肝功能有影响，引起转氨酶升高，并可发生黄疸，故每月应测肝功能１次。孕妇和１２岁以下儿童禁用。大剂量可引起体位性低血压。
Ethionamide (Eto)
Ethionamide is part of a group of drugs used in the treatment of drug resistant TB called thioamides. It is used as part of treatment regimens, generally involving 5 medicines, to treat MDR and XDR TB. It was discovered in 1956.
Ethionamide is used as part of a South Africa’s standard regimen to treat MDR TB.
Dosage:

Adults:	Adults with liver damage - creatine clearance < 30 ml/min:	Children:
15 – 20 mg/kg daily (max 1000 mg)	250 – 500 mg daily	15 – 20 mg/kg daily (max 1000 mg)
Ethionamide is taken twice daily, generally one tablet (250 mg) in the daytime and 2 tablets (500 mg) at night. Ethionamide is taken during the intensive and continuation phases of treatment.

How it works:

Ethionamide is an antibiotic used in the treatment of tuberculosis. The action may be through disruption of mycolic acid.

Side effects:

Ethionamide can cause persistent nausea and vomiting. Decreasing the dosage will decrease the symptoms, which is why ethionamide is taken twice a day. Ethionamide may also cause dizziness and fatigue. Occasionally ethionamide may cause jaundice (yellowing of the skin and eyes) or changes in mood (depression) and allergic reactions. Rarely, ethionamide will cause peripheral neuritis (tingling in the hands and feet) as well as vision disturbances.

It is recommended that ethionamide is avoided during pregnancy as it may increase nausea and vomiting. Ethionamide was shown to be teratogenic  in animal studies.

Ethionamide should not be used in patients with severe liver disease or porphyria (a rare, inherited disease affecting the skin and nervous system). Blood sugar levels should be monitored in diabetic patients.

Clinical evidence and approval:

Ethionamide has received FDA approval for the treatment of tuberculosis in patients resistant or intolerant to other medications.

A prospective uncontrolled study of 39 patients published in 2006, found that regimens containing ethionamide appear to be safe and effective.¹

Ethionamide is part of a group of second line agents used to treat drug resistant TB. The use of thioamides, including ethionamide and protionamide, is recommended before other second line agents (cycloserine or terizidone). There is complete cross resistance between ethionamide and protionamide.²

Evidence shows that strains that are resistant to low concentrations of isoniazid are probably susceptible to ethionamide and prothionamide. However, strains that are susceptible to high concentrations of isoniazid are usually resistant to ethionamide. The use of high-dose isoniazid and ethionamide increases the chance of successful treatment.³

Pricing (per lowest unit, i.e. single tablet or injection):

SA Public sector (Aug 2009 – July 2011 tender)
250 mg	R1.71
SA Public sector (August 2011 – July 2013 tender)
250 mg	R1.45
SA Private sector
250 mg	R1.69
Global Drug Facility4
250 mg	R0.61 US$ 0.09

* Private sector prices sourced on 26/07/11. Global Drug Facility prices converted to rands on 26/07/11.

* Private and public sector prices may vary between suppliers. The lowest available prices are shown here.

Advocacy issues:

• Further research is needed on safety and efficacy for paediatric treatment. Paediatric formulations are not available. Further research is needed on potential interactions with antiretrovirals, including the potential increased risk of liver damage when combined with nevirapine and efavirenz. [MSF]The SA public sector price is 2.8 x higher than available international prices.