Managing Director of Hart Biologicals, Alby Pattison MBE, has spent his entire career working within the haemostasis medical field and as such has worked extensively with different forms of anticoagulants. Here, he gives his opinion on current thinking following the introduction of the new, direct oral anticoagulants (DOACs) and what the future may hold for the ‘tried and tested’ approach using Warfarin:
After five years on the market, the issues surrounding the use of the new DOACs is now becoming clearer.
Initially introduced as an alternative to the anticoagulant Warfarin, DOACs are marketed as a more convenient option for patients needing anticoagulation therapy both in the UK and now in much of the developed world.
The main advantage used to support the use of DOACs has been the fact that unlike Warfarin, patients do not have to undergo regular monitoring to measure the effectiveness of the drug.
Lifestyle changes, the presence of other medications and treatment of infection with antibiotics means that Warfarin needs to be ‘titred’ in each patient by individual attendance at regular monitoring clinics, which quite often results in dose changes to maintain the effectiveness of the treatment.
In contrast, the DOACs do not need monitoring, have fixed dosages and are limited in reaction to lifestyle changes.
The new DOACs have been in use for a limited amount of time compared with the extensive experience medical professionals have with Warfarin. However, the disadvantages of their use are now making themselves known.
No monitoring means that it is difficult to assess patient compliance and drug effectiveness. Patient non-compliance is one of the biggest issues affecting the quality of oral anticoagulation control.
Fixed dosage means that a missed tablet can lead to the loss of protection the anticoagulant affords due to the relative short half-lives of the new drugs. The reversal of overdosing (bleeding) involves the use of even more unmonitored, targeted drugs which block the effect of DOACs.
In contrast, Warfarin has a well-established and robust reversal protocol that simply starts with discontinuing the drug for a few days.
In more severe cases the injection of vitamin K or infusion of human plasma clotting factors can be used to reverse the effect.
The widespread use of the new DOACs over a relatively short period of time has also highlighted a number of issues that were not specifically identified during original clinical trials which has led many professionals to question recommendations made by the pharmaceutical industry.
DOACs have been presented by pharmaceutical companies as the cost-effective way of providing anticoagulation in patients needing it. However, with more time on the market we are now seeing a vast increase in the amount spent by the NHS.
The NHS budget for anticoagulants rose by more than £100 million in 2015/16 and by around £400 million in 2016/17. This is down to the fact that the price of therapy has been wildly misconstrued.
With an estimated 1.4 million people in the UK at risk of stroke and who require long term anticoagulation therapy and at around £800 per course, DOAC therapy could cost the NHS £1.12 billion annually. That’s nearly 1% of the total NHS budget.
The average cost for 12 months therapy with DOAC drugs is around £800, whereas Warfarin costs are around £40-£50 per year, and NICE indicate that the average cost for the clinic management of patients on warfarin is around £240 per year. This means even with clinic management costs, warfarin is still by far the most cost-effective oral anticoagulant.
The cost of DOACs is added to by the expense of the reversal agents which for most of the time are not needed but ‘have to be stocked just in case’.
Finally, although therapy with DOACs does not require regular testing as opposed to Warfarin, the monitoring of patients in a clinic can allow doctors the opportunity to identify any issues that may arise and modify treatment effectively meaning a safer system and closer personal monitoring for the patient.
Patients on DOAC drugs who have problems such as bleeding or thrombosis will end up in A&E or trauma units for treatment.
The evidence so far suggests that while the new agents have a role to play in how we manage patients needing anticoagulation support, we are now starting to see many of the practical issues which were previously unknown, starting to emerge.
It is my belief that Warfarin will be offered to many patients for many years to come as it still offers practical efficacy, affordable cost and value for money.
Hart Biologicals offers a range of anticoagulation monitoring test solutionsincluding the Manchester Capillary Reagent PT test kitthe Fiix Test. For more information on all of the product available from Hart Biologicals click here to view our product catalogue.