More than 85,000 medications are discontinued each year by physicians, yet while physicians share this information with their patients, it is too often not shared with the pharmacists. This communication gap, identified by researchers from Brigham and Women's Hospital (BWH) and Harvard Vanguard Medical Associates, allows discontinued medications continue to be dispensed at pharmacies, representing an important patient safety concern.

The study will be published on November 20, 2012 in the Annals of Internal Medicine.

"This is a novel patient safety issue that has not been measured previously," explained Thomas Sequist, MD, MPH, a physician at BWH and Harvard Vanguard, and senior author of this study. "We found that 1.5 percent all off discontinued medications were refilled by the pharmacy and that 12 percent of those refilled medications caused some degree of potential harm to the patients."

The study was conducted at Harvard Vanguard, and the researchers used electronic medical records to analyze 1,218 medications that were discontinued throughout 2009. They then reviewed a sample of more than 400 medical charts for any adverse events that may have happened due to the fact that the patient continued to take a discontinued medication. After reviewing these charts, they found that 1.5 percent of discontinued medications continue to be refilled by the pharmacy and that of those; potential harm resulted from dispensing these medications in 12 percent of the cases. The harm ranged from serious issues such as low blood pressure and possible allergic reactions, to less serious effects such as lightheadedness or nausea.

With the growing use of electronic medical records, prescriptions are now easily transmitted to pharmacies with the click of a mouse; they can also be discontinued and removed from medication lists in the physician's office with a similar click. However, this study shows that there is little feedback to either physician offices or retail pharmacies to ensure that patients are following the map laid out by this electronic trail. Many physicians may incorrectly assume that the patient will remember to stop taking the particular discontinued medication or that discontinuing a medication in the electronic health record is automatically transmitted to the pharmacy, in the same way that a new prescription is transmitted.

"The implementation of electronic health records have offered a clear opportunity to track when a clinician discontinues a medication, but now there needs to be a process that helps discontinued orders be transmitted electronically to the retail pharmacy," explained Adrienne Allen, MD, MPH, associate medical director of Quality, Safety, and Risk at North Shore Physicians Group, and lead author of this study. "Future research should focus on evaluating methods of improving communication between providers and pharmacies to better reconcile medication lists, as well as explore strategies to improve patient knowledge and awareness of their medication regimen," explained Allen.