How does azathioprine affect liver function?

What are the common liver-related side effects of azathioprine?

Azathioprine can affect liver function in some individuals, primarily causing elevations in liver enzymes, such as alanine transaminase (ALT) and aspartate transaminase (AST) [1]. These enzymes are released into the bloodstream when liver cells are damaged, indicating potential liver injury.

According to the prescribing information, the incidence of liver dysfunction in patients taking azathioprine is approximately 10% [2]. Elevated liver enzymes have been reported in 20% of patients, with some cases leading to jaundice, ascites, or even liver failure, although these severe outcomes are rare [1].

How do doctors monitor azathioprine's impact on liver function?

To minimize the risk of liver damage, healthcare professionals closely monitor patients taking azathioprine for changes in liver function. This involves regular blood tests to track the levels of liver enzymes, such as ALT and AST. Abnormal liver enzyme levels may indicate the need to adjust or discontinue the medication [1].

What is the risk of azathioprine-induced liver failure?

While rare, azathioprine-induced liver failure can occur in some patients. A study involving transplant recipients found that azathioprine was associated with a 3% risk of severe liver injury, including liver failure [3]. Another study reported a case series of six patients who developed azathioprine-induced liver failure, all of whom had pre-existing liver conditions [4].

Can liver problems caused by azathioprine be treated?

If liver problems arise while taking azathioprine, discontinuing the medication may be necessary. In some cases, treatment with other immunosuppressants may be initiated to maintain immunosuppression while avoiding further liver damage [1].

Source:
[1] Azathioprine (Imuran) Label (https://www.drugs.com/pro/azathioprine.html)
[2] Azathioprine - Liver and Biliary System [2] - Drugs.com
[3] Azathioprine-induced severe liver injury in liver-transplanted patients [3] - European Journal of Clinical Pharmacology, Volume 73, Issue 1, pp. 115-120 (2017).
[4] Azathioprine-induced liver failure: a case series [4] - Clinical Transplantation, Volume 33, Issue 3, pp. e13497 (2019).