Life-Style
Flu Watch: June 2009
Monday, June 1, 2009
PTINR.com Staff
Much of the nation's focus is on the H1N1 virus - widespread seasonal flu is appearing in the same 7 states
The flu season runs from the beginning of October through the end of May. Variant strains of the flu virus affect thousands of people during this season, ranging from young children to the most senior of citizens. The US Centers for Disease Control and Prevention (CDC) estimate that roughly 5-20% of the population is infected with the flu each year.1 Symptoms of the flu include, but are not limited to:
| Flu Symptoms |
| fever (usually high) |
| runny or stuffy nose |
| headache |
| muscle ache |
| extreme tiredness |
| stomach, nausea, vomiting |
| dry cough |
| sore throat |
| 1 |
Importantly, the symptoms of the flu can directly influence your international normalized ratio (INR) testing. Fever, vomiting, and diarrhea have been associated with increased INR values, placing you at increased risk of bleeding. The higher the INR result above your target range - the greater the risk is of a major bleeding event. Not all your elevated INR test results will result in a bleeding event, but your risk increases.2
The 7 states reporting widespread H1N1 virus are also the same states reporting widespread seasonal flu for the week ending June 6, 2009.3, 4
Getting plenty of rest, eating healthy meals and washing your hands frequently will help prevent the spread of viruses and bacteria.
The flu kills an estimated 36,000 Americans each year and hospitalizes an additional 200,000 according to the CDC.1 If you experience the flu, you should be especially careful when choosing over-the-counter products to combat flu symptoms. Many over-the-counter medications interact with warfarin and can increase or decrease your INR values. You can ask your care provider for a list of cold and flu products with minimal warfarin (Coumadin ®) interactions.5
More frequent INR testing is also recommended for people on warfarin suffering from the cold or flu, who are potentially at increased risk because their INR values can rise or fall more rapidly.4 Weekly home INR monitoring will allow you accurate test results between office visits, a strategy that has been shown to improve time in target range and significantly decrease the risk of bleeding and stroke.5
References:
Influenza: The Disease (2007). Retrieved January 28, 2009, from Centers for Disease Control and Prevention Web site: http://www.cdc.gov/flu/about/disease/index.htm
Hylek, E.M. et al. (1996). An Analysis of the Lowest Intensity of Prophylactic Anticoagulation for Patients with Nonrheumatic Atrial Fibrillation. NEJM, 335 (8), 540-6.
Weekly US Map: Influenza Summary Update. (2008). Retrieved March 3, 2008, from Centers for Disease Control and Prevention Web site: http://www.cdc.gov/flu/weekly/usmap.htm
Weekly US Map: Influenza Summary Update. (2008). Retrieved June 18, 2009, from Centers for Disease Control and Prevention Web site: http://www.cdc.gov/h1n1flu/
Bristol-Myers Squibb Company. (2007). Medication Guide for Coumadin Tablets and Coumadin for Injection [Package Insert]. Princeton, NJ: Bristol-Myers Squibb Company.
Heneghan C., et al. (2006). Self-monitoring of oral anticoagulation: a systematic review and meta-analysis. The Lancet, 367, 404-11