An antiretroviral drug used in the management of HIV is at the centre of a liver damage warning issued in the United States.
The US Food and Drug Administration has warned patients taking Videx (didanosine) that they were at risk of developing non-cirrhotic portal hypertension, a rare but serious liver disorder.
FDA said that it received 42 reports of non-cirrhotic portal hypertension in the 18 years since the drug was registered in the US, with three patients needing liver transplants and four patients dying from bleeding or liver failure.
Duration of Videx treatment ranged from months to years before the development of the condition.
"A causal association is difficult to determine from postmarketing reports alone," FDA said in a statement.
"However, based on the number of well-documented cases and exclusion of other causes of portal hypertension such as alcohol-related cirrhosis or hepatitis C, FDA concludes there is an association between use of didanosine and development of non-cirrhotic portal hypertension."
The regulator said it decided to keep the drug on the market because "the clinical benefits of Videx in certain patients with HIV continue to outweigh potential safety risks".
FDA has added new warnings to the drug's label about the signs and symptoms of the liver disorder.
According to the new warning, patients "should be monitored for early signs of portal hypertension during routine medical visits".