If you’re taking anti-coagulant pills, you have a choice between warfarin or one of the New Oral Anti-Coagulants (NOAC) such as Pradaxa/dabigatran, Xarelto/rivaroxaban or Eliquis/apixaban. We’ve chosen Pradaxa/dabigatran as the representative of the NOACs for this quiz.
How much do you know about their differences? Completing this quiz may help you realise why either one is best for you.
Score yourself out of ten
- Less than 4 – Coagulation Crisis
- 4 to 6 – Coagulation Competent
- 7+ – Coagulation Conqueror
So, for each of these possibilities, is it warfarin or dabigatran that ….
Warfarin was initially used as rat poison, it was called Rodenticide and was the bestselling rat poison in the USA. Carl Link who developed Warfarin believed that it was too dangerous to use as medication. It was only after a soldier took a large overdose of rat poison and survived that Doctors believed that warfarin may be safe.
Many factors seem to affect a person’s response to warfarin, as a result some people only need a small doses of warfarin whereas others need much more. Warfarin metabolism is also affected by diet, exercise, and other medication. It is recommended that warfarin is monitored regularly to ensure the dose is safe. Dabigatran is given at a fixed dose and does not need monitoring, but some doctors are concerned that a fixed dose may not be right for everybody especially if you have a very low body weight.
Dabigatran is significantly more expensive than warfarin. One tablet of dabigatran costs about the same as a month’s supply of warfarin, however the price varies between countries and some will have large subsidies to keep the price down. Also the cost of warfarin monitoring needs to be considered when comparing costs.
Dabigatran must be kept in its original packaging. It comes in a blister card with each tablet stored individually. Some people like all their medication in a calendar style blister pack to help them take their medication on time. Unfortunately dabigatran cannot be repackage with other medication in a blister pack, whereas warfarin can be stored with other medication.
Warfarin can be reversed in two ways; it can be reversed immediately with a plasma product containing several clotting factors (called Prothrombinex in Australia and New Zealand) or reversed more slowly with vitamin k. Prothrombinex is given intravenously for very severe bleeds and vitamin K is usually given orally for less severe bleeding or to reverse a high INR result.
Dabigatran does have a reversal agent, however this is not available in all countries yet and is expensive.
Many antibiotics can enhance the effects of warfarin and make the INR result too high. It is recommended that you have an INR check a few days after starting any new treatment. Remember there are some antibiotics that have the opposite effect and make warfarin less responsive. Talk to your doctor if you are worried about starting new treatment.
Dabigatran has less interactions, but some antibiotics can alter its metabolism including clarithromycin and rifampicin.