【缺藥訊息】 公告日期：2023/7/11。 缺藥品項：Imuran 錠劑 50mg。 缺藥原因：因供應問題缺貨。 替代藥品：國內有同成份規格替代品。 配套措施：採購替代品，庫存量用罄關檔停用，替代品預計於7/12到貨 (依照實際到貨日為準)。

Renal transplant rejection, adjunct, prophylaxis;
Rheumatoid arthritis

Azathioprine is an imidazolyl derivative of 6-mercaptopurine and acts as an immunosuppressive antimetabolite.
The exact mechanism of immunosuppressive action is unknown because the exact mechanism of the immune response itself is complex and not completely understood.
Azathioprine suppresses cell-mediated hypersensitivities and causes alterations in antibody production.

[Absorption]
well absorbed

[Distribution]
Protein Binding: 30%

[Metabolism]
Metabolism Sites: Liver, Azathioprine is a prodrug and is extensively metabolized to 6-mercaptopurine via oxidation or methylation in the liver and erythrocytes.

[Excretion]
Kidney, renal clearance is 57.3 mL/min/kg

Hypersensitivity to azathioprine;
pregnant women with rheumatoid arthritis;
rheumatoid arthritis, prior treatment with alkylating agents (eg, cyclophosphamide, chlorambucil, melphalan, or others), increased risk of malignancy

D [FDA]

Infant risk cannot be ruled out. [MDX]
Avoid breastfeeding. [WHO]

(Frequency not always defined; dependent upon dose, duration, indication, and concomitant therapy.)

[Central nervous system] Malaise
[Gastrointestinal] Nausea and vomiting (rheumatoid arthritis: 12%), diarrhea
[Hematologic & oncologic] Leukopenia (renal transplant: >50%; rheumatoid arthritis: 28%), neoplasia (renal transplant 3% , 0.5% ), thrombocytopenia
[Hepatic] Hepatotoxicity, increased serum alkaline phosphatase, increased serum bilirubin, increased serum transaminases
[Infection] Increased susceptibility to infection (renal transplant 20%; rheumatoid arthritis <1%; includes bacterial, fungal, protozoal, viral, opportunistic, and reactivation of latent infections)
[Neuromuscular & skeletal] Myalgia
[Miscellaneous] Fever

[Renal transplant rejection, adjunct, prophylaxis]
(initial) 3 to 5 mg/kg as a single daily dose starting at the time of transplant; less commonly, therapy is started 1 to 3 days prior to transplantation; IV azathioprine therapy (as sodium salt) is typically administered initially, and then patients are switched to oral therapy (at the same dosage) after the postoperative period
(maintenance) 1 to 3 mg/kg/day PO

[Rheumatoid arthritis]
(initial) 1 mg/kg/day PO as single dose or divided twice daily; may titrate by 0.5 mg/kg/day after 6 to 8 wk and every 4 weeks thereafter; MAX dose is 2.5 mg/kg/day
(maintenance) may lower dose 0.5 mg/kg/day Q4W (while keeping other drug therapy constant) until lowest effective dose is reached

Safety and efficacy not established in pediatric patients.

[Renal impairment] Usually administered at lower doses.

Nil.

Store azathioprine tablets at 15 to 25 degrees C in a dry place and protect from light.