Polypharmacy in elderly people: An estimation of prevalence of potential risks

BACKGROUND Pharmacotherapy for elderly and often chronically multimorbid patients may cause to polypharmacy, defined as a drug schedule with more than five different systemic medications at the same time.Polypharmacy may lead to an increased risk of adverse drug events, of critical drug-drug interactions, of potentially inappropriate medication for elderly patients ("Beers list") and of non- adherence. This research, based on data of a community pharmacy in Brandenburg, Germany, intended to determine the prevalence of polypharmacy, of prescriptions of potentially inappropriate medication for elderly patients, of critical drug- drug interactions as well as the number of prescribing physicians per patient. METHODS In Germany, about 90% of the population are covered by the statutory health insurance. The database consisted of pharmacy claims of a pharmacy and the statutory health insurance covering three months. 1427 patients older than 65 years were included. Out of pocket medications were not taken into account. The mean age was 75.3 (±7.1) years, 64% were female and 39% male. RESULTS Prescriptions of more than five agents could be found in 29.8% of the patients, 4.2% got nine or more different agents. Among those with five or more agents, there were seven patients with potentially life-threatening drug-drug interactions (six of them between theophylline + non-cardioselectiv beta-blockers, one of them beta- sympathomimetic+ beta- blocker).Furthermore, there were 340 potentially severe critical drug-drug interactions (e.g. 53 of them between ace-inhibitors + non-steroidal anti-inflammatory drugs).With the increasing number of medications, the number of patients with critical drug –drug interactions increased from 40% having five medications to 81% having nine or more medications at the same time. The medications were prescribed by an average of 1.83 physicians per patient.Non-recommended medications from the “Beers list” received 4.9% of the elderly patients: 21 indometacin, 13 amitriptiline, 13 diazepam, 8 oxybutinin, 4 doxepin, 4 ticlopidine, 3 short-acting nifedipine, 2 amiodarone, 1 promethazine, 1 fluoxetine. DISCUSSION Our research points out, that polypharmacy is a relevant problem in the German health care system. Further research is necessary to find out how the potential risks of polypharmacy really impact the life expectancy and quality of life of elderly, chronically multimorbid patients. Moreover, it is to reassess priority and necessity of the components of polypharmaceutical therapy.