New Guidelines on Aspirin, Asthma, and Influenza
Mar 27th 2020
What are the hot topics and clinical trends in internal medicine that clinicians are talking about? Two expert internists took some time recently to discuss their thoughts on these issues.
Donald L. Deye, MD, FACP, is a general internist who has practiced for over 30 years at Cambridge Medical Center in Cambridge, MN. He is also Chief Medical Officer for Oakstone, and host of the acclaimed MKSAP Audio Companion. Timothy Leigh Rodgers, MD, is an internal medicine specialist practicing in Santa Barbara, CA.
Aspirin: No Benefit for PRIMARY Prevention of Cardiovascular Disease
Dr. Deye: Let’s talk about the ASPREE trial. This made big news. It studied the impact of using aspirin for primary prevention of cardiovascular disease and cancer in elderly patients. The key to this study is that this was PRIMARY prevention, meaning the study excluded patients with coronary artery disease, diabetes, any evidence for atherosclerosis or high risk medical conditions for developing atherosclerosis.
When this study appeared in news stories, this distinction was not emphasized and many elderly patients with diabetes, coronary artery disease, and peripheral artery disease thought that they should stop taking aspirin. In this low risk group, investigators found that aspirin did not prevent significant cardiovascular outcomes, mortality, or cancer incidence after long term follow up. The American Diabetes Association has also looked at this and come to the same conclusion.
ASPREE also found that there was an increased risk for bleeding such as subdural hematomas and GI bleeding in the patients taking daily aspirin.
So it looks as if we should not be recommending aspirin for primary prevention of cardiovascular disease or cancer, in patients without atherosclerosis or at high risk for this. Most likely guidelines are going to be changing based on these findings.
Mild Persistent Asthma: As Needed vs Fixed Dosing
Dr. Deye: So Tim, there’s been some rumble about treatment of mild persistent asthma coming from a study called the Sigma Trial. I’ve heard of something called Six Sigma. What exactly was the Sigma Trial?
Dr. Rodgers: Well, Don, the Sigma trial showed that in patients with mild, persistent asthma, we should consider telling them to take inhaled corticosteroids and long acting beta agonist medications only as needed instead of twice a day every day, on a schedule. This costs much less and has equally good outcomes.
In the Sigma trial, patients were also told to take albuterol or terbutaline as needed. The study showed that patients who took the meds as needed did just as well in terms of asthma exacerbations and trips to the emergency room as those on the every day scheduled regimen.
Dr. Deye: A key point here is that other studies have shown that patient adherence to daily scheduled use of inhalers is quite poor, with only a third of patients actually using these medications daily as prescribed.
Dr. Rodgers: It should be pointed out, however, that people who took the fixed dose had slightly better symptoms control, so that regimen still is better ideally. But in the real world where compliance is flawed, as needed dosing might be the better alternative, partly because it is much less expensive for the patients with noninferior outcomes.
Dr. Deye: Roger that, Dr. Rodgers! It’s important to understand that people with mild asthma still can have severe asthma attacks leading to hospitalization and even death. Even so, prn dosing may be a way to positively impact this very large group of asthmatic patients with something they are actually going to use as prescribed. According to some analysts, switching patients with mild persistent asthma to the as-needed regimen could save a billion dollars a year!
Where Does Baloxavir Fit in For Flu?
Dr. Rodgers: Don, another timely practice changing study recently appeared discussing a new drug called baloxavir. What’s the scoop on that?
Dr. Deye: Some very interesting data has appeared on baloxavir, which is a new single dose oral medication for treatment of influenza. One big advantage of baloxavir is that you only need a single dose instead of the bid dosing for five days that is required for oseltamivir. This study appeared in the New England Journal of Medicine and does show that the single dose of baloxavir appears to work better than oseltamivir because symptoms improved faster with the new medication.
Dr. Rodgers: A key point is that the duration of infectivity with baloxavir is only about two days compared to three to four days with oseltamivir. There’s one other important feature of this study which may limit which patients should use it for now. The study only evaluated patients with relatively mild flu, so we really don’t know how well this will work in patients with severe influenza, including those who require hospitalization. So for now, caution is advised. Until we get more data from patients with severe disease, we should probably limit use of baloxavir to patients with mild symptoms, sticking with oseltamivir for the more severe cases.