A new study highlights potentially problematic prescribing cascades that occur when people are given a medication to help them deal with an adverse drug reaction caused by a previously taken prescription medication. Overall, the benefits of taking a medication to deal with the adverse drug reaction from a previously taken medication may not outweigh the risks of taking the additional drug, the study finds.
The report was published Sept. 20 in The Journal of the American Geriatrics Society.
Researchers looked at existing studies and then 16 pharmacists and doctors identified prescribing cascades in the studies that could be harmful. The team also conducted a study on pharmacy data and specified that an adjusted sequence ratio (aSR) greater than one was defined as a prescribing cascade. A separate analysis calculated aSRs for older adults.
Investigators found significant positive aSRs for 62.1%, or 41, of the prescribing cascades; that means of the 76 cascades identified, 66 were potentially harmful and 41 were thought to have significant impacts. The aSRs were significant for 37 of the prescribing cascades identified in older adults, specifically.
The highest aSR was found for amiodarone potentially causing hypothyroidism treated with thyroid hormones. The biggest population affected by a cascade was in 34,645 taking angiotensin converting enzyme-inhibitors and the potential for the drugs to cause urinary tract infections treated with antibiotics.
Polypharmacy may cause the same adverse drug reaction and can increase the likelihood of a prescribing cascade, the authors noted.
Prescribing cascades can lead to excess medication burden, which is a concern especially in older adults. They’re not always intentional to manage an adverse drug reaction; sometimes it happens because the reaction is deemed a new condition, the authors noted. “Despite being assessed as problematic in general, some prescribing cascades are unavoidable in individual cases that relate to a condition or situation for which there is no alternative treatment,” the authors wrote.
