Consider your condition and more when selecting an anticoagulation medication

By: Alere Staff

Warfarin has been in use effectively treating blood clots since 1955.1 We know warfarin, we understand it and are comfortable with how to advise therapies around it. We are able to measure the effectiveness of the drug with a simple INR blood test that has been even further simplified with the ability to test at home. We also have a solid enough understanding of interactions, enabling us to often predict the effect on the INR for proactive warfarin dosing.

Novel Oral Anticoagulants (NOACs), introduced in 2010, work differently in the clotting cascade than warfarin and offer the convenience of not requiring an INR test. For some, this is viewed as a major step forward in the world of anticoagulation. However, for patients that fall into the high-risk category, there is little information available to assist with NOAC therapy in these high risk populations.1 Patients that are considered high-risk are those with chronic kidney disease (CKD), those that are more than 75 years old and those who have had a previous stroke.

Uncovering the data regarding high risk conditions and type of anticoagulant

Due to the lack of long-term safety data and adequate data to support use in patients with severe kidney disease, NOACs have a general disadvantage over warfarin.3 To date, no published reviews have evaluated the effect and safety of NOACs for patients with chronic kidney disease (CKD) compared to warfarin, specifically those with creatinine clearance of less than 50ml/min.2 One study concluded that there is no significant advantage of warfarin over NOACs for these patients, however, the ability to monitor INR levels showed positive results in regards to stroke prevention and bleeding risk.2

Patients that are over 75 years old raise caution with healthcare professionals when considering anticoagulation. Stroke and bleeding events are important factors in this decision. The elderly often have multiple illnesses occurring together that could impact the effects of these medications. Unfortunately, the NOAC studies meant to determine patient safety included very few of this patient type, resulting in minimal guidance to offer healthcare professionals.4

Patients that have had a previous stroke raise even further caution when considering anticoagulation options. The first stroke is unfortunate enough but subsequent strokes can be detrimental. Due to the limitations of the NOAC studies, this high risk population was typically not included in the study population, providing results based on an extrapolation or small sample size. Again, minimal guidance is offered when prescribing anticoagulation.

Knowing how prevalent any of the scenarios are, it makes sense that healthcare professionals still use and recognize the safety of warfarin. A simple INR test seems of little consequence when it provides peace of mind with INR testing. The availability to test at home leading to increased time in therapeutic range makes warfarin therapy an appealing option for anticoagulation. It is well documented that increased time in therapeutic range leads to increased patient safety and less critical events.5

References:

  1. Hanley, Colleen M., Kowey, Peter R., (2015). Are the novel anticoagulants better than warfarin for patients with atrial fibrillation? Journal of Thoracic Disease, 5;7(2): 165-171. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4321074.
  2. Harel, Ziv. et al. (2014). Comparisons between Novel Oral Anticoagulants and Vitamin K Antagonists in Patients with CKD. Journal of the American Society of Nephrology, 25: 431-442. Retrieved from http://jasn.asnjournals.org/content/25/3/431.full.pdf+html.
  3. Faloon, William (2015). Important Data on 3 New Oral Anticoagulants. Life Extension Magazine. July issue. Retrieved from http://www.lifeextension.com/magazine/2015/7/important-data-on-3-new-oral-anticoagulants/page-01.
  4. Kato, Eri Toda, (2014). New Oral Anticoagulants in Elderly Patients With Atrial Fibrillation. American College of Cardiology. Retrieved from http://www.acc.org/latest-in-cardiology/articles/2014/12/10/11/28/new-oral-anticoagulants-in-elderly-patients-with-atrial-fibrillation.
  5. DeSantis, G., et al. (2014). STABLE Results: Warfarin Home Monitoring Achieves Excellent INR Control. The American Journal of Managed Care.