Overview
Eltrombopag is a small-molecule thrombopoietin receptor agonist indicated for adult chronic immune (idiopathic) thrombocytopenic purpura (ITP) in splenectomised patients who are refractory to other treatments. It can be considered as second line treatment for adult non-splenectomised patients where surgery is contraindicated as well1. The other indications are for thrombocytopenia patients with chronic hepatitis C virus infection and acquired severe aplastic anaemia which is refractory to prior immunosuppressive therapy¹.

Background of Safety Issue

The United Kingdom Medicines and Healthcare Products Regulatory Agency (MHRA) had reported the risk of interference with bilirubin and creatinine test results with the use of eltrombopag². Several cases and publications of potential negative interference (falsely low/normal results) from eltrombopag on bilirubin testing have been reported, as well as positive interference (falsely high/normal results) on creatinine testing².
In Malaysia, currently, there are two (2) products containing eltrombopag registered with the Drug Control Authority (DCA)³.

Adverse Drug Reaction Reports⁴

The NPRA has received a total of 20 reports with 27 adverse events related to eltrombopag containing products. The most reported adverse event were drug ineffective (3), no therapeutic response (2) and thrombocytopenia (2). There have been no reports of interference with bilirubin or creatinine test results received by NPRA to date.

Action taken by NPRA
NPRA is currently in discussion with the product registration holder of eltrombopag to update the package insert with this new information.

Advice for Healthcare Professionals

• If the laboratory results and clinical observations (jaundice) are inconsistent, evaluate contemporaneous aminotransferase values to determine the validity of low total bilirubin levels.

• In the event of an unexpectedly high serum creatinine, blood urea should be evaluated.

_DISCLAIMER

_{This publication is aimed at health professionals. The information is meant to provide updates on medication safety issues, and not as a substitute for clinical judgement. While reasonable care has been taken to verify the accuracy of the information at the time of publication, the NPRA shall not be held liable for any loss whatsoever arising from the use of or reliance on this publication.}