Pradaxa, also known as dabigatran, has been linked to 50 deaths around the world since its launch this year.

In July, Pharmac began to fund Pradaxa for New Zealanders as a replacement blood-thinning drug to warfarin.

Many GPs were pleased that Pradaxa would be funded due to the cost and disruption of regular blood tests that users of warfarin had to undergo, but others have remained sceptic.

Trials for the drug found that at certain doses Pradaxa had a lower risk of bleeding and stroke than warfarin. It can not, however, be monitored and there is no antidote if bleeding occurs.

A Sunday Star Times investigation has revealed that at least four elderly heart patients have died while taking Pradaxa, after suffering unstoppable bleeding.