One of the world's most commonly prescribed drugs could be risking the lives of thousands of patients around the world

A New Zealand-led trial has compared the risk of death across different types of stomach ulcer-preventing medicines, used on patients in hospital intensive care units.

It found that while proton pump inhibitors, such as Losec, are slightly better at preventing bleeding from ulcers, they might actually lead to more deaths.

Lead author Paul Young says prior to the study there was a lot of speculation around what drug to use.

He says we finally have data that is useful and informative for clinical decision making.