Pradaxa: Not so bleeding obvious

The decision to delay further the introduction of subsidies for the anti-stroke drug, Pradaxa,  puts Australia at odds with the rest of the developed world.

It also raises questions about the Government’s handling of Australia’s widely-respected Pharmaceutical Benefits Advisory Committee, (PBAC).

It was that committee which 18 months ago recommended that the new oral  anticoagulant, dabigatran,  widely known by its commercial name,  Pradaxa, be listed on the Pharmaceutical  Benefits Scheme as a subsidised precription drug.

The move would benefit many thousands of stroke-susceptible Australians, replacing the somewhat hazardous and unpopular  existing anti-coagulant, warfarin.

But the Pradaxa  listing would be at big cost — an estimated  $500 million to as high as $1 billion a year, depending on usage levels.

Given Pradaxa’s acceptance as a subsidised anti-clotting medicine in western countries, including the United Kingdom, Canada and NZ, Australia’s continued refusal to list Pradaxa might strike many people as  the latest example of the Government’s budget surplus obsession.

However Health Minister, Tanya Plibersek, has been able to cite the views of veteran subsidised drug expert, Professor Lloyd Sansom, in defence of the decision.

Professor Sansom, known as a straight-shooter in the highly fraught field of big-buck drug decisions, was commissioned by the Government to report  on the issue after the PBAC recommendation.

That step itself was a highly unusual second stab.   Sansom for a decade chaired the PBAC which gave the original positive recommendation.  He was asked to do a review of the Pradaxa decision on his retirement.

It’s a tricky area.  As the Sansom report says, the use of anticoagulants like warfarin and Pradaxa in the prevention of stroke in patients with irregular heart rhythm, or  atrial fibrillation, “is a balance between reducing the risk of ischaemic stroke and minimising the risk of bleeding”, particularly as a result of brain haemorrhage.

Up to 300,oo Australians, most of them older people, have atrial fibrillation, raising their risk of stroke at any time, but many have no symptoms and are unaware of the risk.

Months passed as the Pradaxa review process dragged on, putting off a crunch decision by a cash-strapped Government, at significant saving to the federal budget.

“Significant uncertainty”

But who knows at what loss in terms of lives and preventable, costly strokes?

The Sansom report released this week is an exhaustive examination of the subject which on one hand says, yes Pradaxa does reduce haemorrhagic  strokes.  But Pradaxa’s impact on ischaemic stroke and bleeding rates compared to warfarin varies and there is no direct head-to-head comparative data available on that score.

The Pradaxa-type drugs are “new medicines and there is significant uncertainty about their safety, effectiveness and cost-effectiveness”  in routine patient use, the report says.

In a separate development, Pradaxa has been linked to 500 deaths in the United States over a two-year period,  the Bloomberg news agency has reported and is now involved in up to 150 lawsuits related to serious side effects.

But a finding by the US Food and Drug Administration recently stated that Pradaxa, did not appear to have higher bleeding rates than with warfarin.

“Pradaxa provides an important health benefit when used as directed,”  the FDA stated after an assessment of US insurance claims data.

Plibersek asserts that Australia is “a world leader in health technology assessment and we make no apology for thoroughly assessing the effectiveness and cost-effectiveness of new drugs;  balancing access to new medicines while also protecting public safety”.

The Government has won some support for its decision to seek yet more data, including on safety issues, from the Consumer Health Forum and from the prescribing advisory body,  NPS Medicinewise.

The Sansom report suggests better monitoring of patients on warfarin, already available from routine pathology tests, and wider use of the existing therapy, would deliver big benefits without the need to provide a new, much more expensive but more easily-administered drug.

Warfarin risks worry GPs

That however would take a substantial behavioural change by clinical staff and patients not so far evident after years of warfarin use and resulting haemorrhages.

Surveys show that as many as a third of GPs believed the risks of prescribing warfarin were “unacceptably high”.  General reluctance to prescribe the drug is also borne out by another result showing that only 55 per cent of eligible patients were prescribed the drug on discharge from hospital.

Plibersek’s statement also shadows the independent status of the PBAC, which must recommend a drug before Cabinet can approve a  PBS listing.  The PBAC’s significance has relied on its independence from Government in recommending what drugs Australia should subsidise.

Plibersek said this week that the PBAC “has now advised me that it is of a mind to rescind its March 2011 recommendation for dabigatran”.

The Minister said that the PBAC felt there was an “appropriate place in clinical treatment for the newer anticoagulant medicines, but would like to see further economic modelling to show the value of these new anticoagulants, in light of the additional infomation now available”.

While the Government’s painstaking approach on this issue may be helping the federal budget, the real bottom line it should be judged on in this matter is Australia’s health.

As Sansom baldly states:  “An improvement in the management of stroke prevention in patients with atrial fibrillation is required”.

Declaration: Mark Metherell has written a political briefing for consultants Ethical Strategies, whose clients include Boehringer Ingelheim, the makers of Pradaxa.