Aspirin therapy: Evaluating benefits and risks
The prevalence of OTC aspirin use is unknown, but with all the publicity about its potential benefit for cardiovascular health and cancer prevention, it’s wise to assume many of your patients are using it. Recent data regarding aspirin therapy reinforce the need to evaluate potential benefits and risks in each patient.
A recent study evaluated the overall benefit of aspirin use for primary prevention of cardiovascular events.1 Data for patients with and without diabetes who were taking placebo or aspirin were evaluated to determine the incidence of hospitalization for major bleeds (cerebral hemorrhage or gastrointestinal bleeds). The aspirin dose was less than 300 mg daily, and patient data were collected for a period of approximately 6 years. The researchers found that those taking aspirin and those with diabetes (regardless of aspirin use) had a significantly higher incidence of one of the adverse outcomes. These data reinforce the opportunities for pharmacists to counsel patients on the use of aspirin and potential risks to keep in mind. The data also suggest that individuals with diabetes, regardless of aspirin use, might benefit from a brief conversation about watching for increased risk of bleeding.
The most recent guidelines for aspirin use from the American Diabetes Association suggested using low-dose aspirin (75–162 mg) as primary prevention for cardiovascular disease (CVD) in individuals with type 1 or type 2 diabetes and a 10-year cardiovascular risk greater than 10%.2 This would include most men older than 50 years and women older than 60 years with at least one additional risk factor (e.g., dyslipidemia, hypertension). Clinical judgment regarding the use of aspirin is recommended for those with a 10-year cardiovascular risk of 5% to 10%. Low-dose aspirin for secondary prevention also is recommended in patients with diabetes who have a history of CVD.
Often the only evidence of aspirin’s antiplatelet activity is increased bruising or bleeding. A recent evaluation was completed to determine if enteric coating/absorption affected response.3 A total of 400 patients took 325 mg aspirin in either immediate-release (IR) or enteric-coated (EC) formulation. Cyclooxygenase-1 activity was measured to evaluate response. Approximately 50% of patients taking 325 mg EC aspirin appeared to have aspirin resistance compared with no resistance among those taking the IR product. However, subsequent analysis revealed that rather than resistance, the issue was related to the type of aspirin used and the timing of administration. This study suggested that the IR formulation should be used to ensure absorption, and ultimately therapeutic benefit of antiplatelet activity, especially in patients using aspirin for secondary prevention only.
CVD is the leading cause of death in women; thus, many are told to take aspirin for either primary or secondary prevention. In 2004 (survey 1) and 2009 (survey 2), women from 127 facilities were assessed for health attributes, including CVD risk factors and aspirin use.4 Slightly more than 218,000 women responded to the surveys, and 29,701 were told by their health care provider to take aspirin based on their profile and guidelines. The results showed that 41% of women who met criteria for primary prevention were taking aspirin as recommended, while 48% who met criteria for secondary prevention were taking aspirin as recommended. From survey 1 to survey 2, a significant increase was seen in use for primary prevention, but no change was seen in use for secondary prevention. These data suggest that pharmacists have an opportunity to identify women who should be using aspirin and educate those for whom aspirin therapy is recommended.
J Womens Health (Larchmt). 2012;21(4):379–87