(Reuters Health) - People taking blood-thinning medications often use over-the-counter (OTC) medicines with the potential to cause dangerous internal bleeding, a recent study suggests.
The study focused on 791 patients prescribed apixaban, one of several newer blood thinners known as NOACs (non-vitamin K antagonist oral anticoagulants) that are recommended to prevent stroke in people with atrial fibrillation, a heart rhythm disorder.
Almost all of these patients used over-the-counter medicines, and 33% of them took at least one nonprescription drug daily or most days of the week with the potential to cause dangerous side effects when combined with apixaban. And almost 7% of them regularly took two or more over-the-counter medicines that could be a dangerous mix with apixaban.
“New OTC products are constantly being adopted by patients,” Dr. Derjung Tarn of the David Geffen School of Medicine at UCLA and colleagues write in the Journal of the American Geriatrics Society. “This study demonstrates that patients have limited knowledge about potential serious interactions between OTC products and apixaban.”
In atrial fibrillation, electrical impulses in the upper chambers of the heart are chaotic, causing the heart muscle to quiver rather than contracting normally. As a result, blood doesn’t flow smoothly through the heart. This can lead to the formation of clots that can then travel through the arteries to the brain.
NOACs are the drug of choice for stroke prevention in patients with atrial fibrillation, which occurs most frequently in older patients. Apixaban is one of the most frequently prescribed. Others include dabigatran, rivaroxaban, and edoxaban.
Unlike the older blood-thinner warfarin, which required regular blood tests to prevent side effects, most people prescribed apixaban or other NOACs are not followed in specialized anticoagulation clinics or monthly by health care professionals, the study team writes. As a result, they may not be aware of potential drug interactions.
In the current study, researchers surveyed patients prescribed apixaban in 2018. They asked patients how often they took over-the-counter remedies like aspirin, ibuprofen, naproxen, and acetaminophen. They also asked about common dietary supplements, including Chinese herbs, various fish oils, ginger and herbal teas.
Aspirin was the most commonly used nonprescription treatment in the study, and almost two-thirds of people on aspirin also took at least one other over-the-counter medicine with the potential to increase the risk of bleeding when mixed with apixaban.
The study didn’t look at whether mixing over-the-counter medicines or supplements with blood thinners actually caused bleeding or other dangerous side effects in these patients.
One limitation of the analysis is that researchers relied on patients to accurately recall and report on what over-the-counter medicines and supplements they used.
It’s also not clear from the study whether people started using any of these nonprescription remedies before or after they were prescribed apixaban.
“Patients who have taken OTC medications or dietary supplements without any problems prior to starting apixaban may not consider potential interactions, particularly if they ingest the supplements as part of their diet,” the study team writes.
“For example, certain ethnic groups may regularly incorporate dietary supplements, such as turmeric and Chinese herbs, in their meals,” the study team notes. “Unless providers ask them, patients may not realize these are important to disclose.”
SOURCE: bit.ly/36aNTHG Journal of the American Geriatrics Society, online October 28, 2019.