New or novel oral anticoagulants (or NOACs) are now available as an alternative treatment to warfarin.
NOACs include dabigatran, rivaroxaban and apixaban.
They have recently been approved by NICE (National Institute for Heath and Care Excellence) for the prevention of strokes in patients with AF. These new drugs work in a similar way to warfarin by increasing the time it takes for your blood to clot. They have been shown in clinical trials to be at least as effective as warfarin.
They have the advantage over warfarin that there is no need for regular blood tests. They are also less affected by different foods and, providing you take the tablet as instructed, the levels will remain stable.
The main disadvantage with these medications is that they are not as easy to reverse as warfarin if you experience bleeding problems. Drug manufacturers are currently looking at developing antidotes for the new medications, and these are estimated to be available within the next 2-3 years.
The side effects of these medications are similar to warfarin. When you are on a NOAC, you are likely to bruise easily and it will take longer for a simple cut to stop bleeding. The most serious side effect of NOACs is prolonged or heavy bleeding, although the risk of serious bleeding is less than warfarin.
You should contact your doctor immediately if you experience any of the following:
- prolonged nose bleeds (more than 10 minutes)
- blood in vomit
- blood in sputum
- passing blood in your urine or faeces
- passing black faeces
- severe or spontaneous bruising
- unusual headaches
- for women, heavy or increased bleeding during your period or any other vaginal bleeding.
You should seek immediate medical attention if you:
- are involved in major trauma
- suffer a significant blow to the head
- are unable to stop the bleeding.
Not all AF patients will be a suitable to receive these new medications.
If you are waiting for a catheter ablation for the treatment of your AF, because of the lack of antidote for bleeding you may need to be switched to warfarin, but this will be discussed with you in detail.
If you have a metal (or mechanical) heart valve you will not be suitable for a NOAC and will be prescribed warfarin instead.
Dabigatran is available in two different strengths (either 150mg or 110mg capsules) and should be taken twice a day with meals.
The 150mg dose is the only NOAC that has been shown to be better than warfarin at preventing strokes in patients with AF. The 110mg dose has been shown to be equivalent.
Depending on your age, weight, kidney function, other medical conditions you have and the tablets you are taking, your doctor or healthcare professional will decide with you which dose is the most appropriate.
The most common side effect people experience with dabigatran, other than bleeding and bruising easily, is indigestion or heart burn. These gastrointestinal side effects occur in around 10 per cent of patients. This can be minimised by taking your capsules with food and making sure that you swallow them whole.
If you experience indigestion, speak to your doctor as they may want to give you a medication to reduce the acid in the stomach. These medications are sometimes known as PPIs (proton pump inhibitors) and include omeprazole, lansoprazole and pantoprazole.
It is important that if you vomit blood, see blood in your urine (making it red or brown) or have blood in your stools (making it look red or black), you contact your doctor immediately.
Rivaroxaban is available in two different strengths (20mg and 15mg tablets) and should be taken once a day. It is best to take the medication with your biggest meal of the day, at the same time each day. We will normally recommend that you take it with your evening meal. This helps to ensure that the medication is absorbed properly into the bloodstream.
Rivaroxaban has been shown to be equivalent to warfarin in preventing strokes in patients with AF.
Depending on your kidney function and other medical conditions, your doctor or healthcare professional will decide with you which dose is the most appropriate. Rivaroxaban is sometimes tolerated better than dabigatran. However, the same bleeding risks still apply with this medicine.
Apixaban is available in two different strengths (5mg and 2.5mg tablets) and should be taken twice a day.
Depending on your age, kidney function and body weight, your doctor or healthcare professional will decide with you which dose is the most appropriate.
If you have had a bleed or ulcer in your stomach, your doctor may prefer you to be prescribed apixaban rather than warfarin or one of the other NOACs. This is because apixaban is the only NOAC that has been shown to have lower rates of gastrointestinal (or stomach) bleeding in comparison to warfarin.