Potentially inappropriate medication prescriptions among elderly nursing home residents: their scope and associated resident and facility characteristics

Health Services Research, Oct, 2004 by Denys T. Lau, Judith D. Kasper, D.E.B. Potter, Alan Lyles

The most common PIRx found in this study--use of propoxyphene, diphenhydramine, hydroxyzine, oxybutynin, amitriptyline, cyproheptadine, iron supplement, and ranitidine--are generally not considered to have extremely dangerous effects. However, they are viewed as inappropriate because of their lack of efficacy compared to alternative agents or their potential for adverse side events. Propoxyphene, a narcotic analgesic that tends to induce dizziness and addictiveness, accounted for one-third of the PIRx cases. Other analgesics, such as aspirin and acetaminophen, may be safer and equally effective. Three antihistamines with potent anticholinergic effects (diphenhydramine, hydroxyzine, and cyproheptadine) collectively accounted for one-quarter of the PIRx cases. Using nonsedating antihistamines, such as fexofenadine and loratadine, would have similar therapeutic effects (Meltzer 1991). Amitriptyline is considered inappropriate for treating depression among elderly patients; other antidepressant agents, such as selective sertonin reuptake inhibitors (SSRIs), are preferred (Omnicare 2000).

Associated Resident and Facility Characteristics

The therapeutic classes most involved in PIRx were psychotropic agents, perhaps explaining why the presence of mental disorders was associated with increased risk of PIRx. This is troubling in light of the 1986 NH reform to regulate the proper use of psychotropic medications, including antipsychotic, anxiolytic, and sedative drugs (Castle 2001). Use of these mind-altering agents as medical restraints to control NH residents has been documented and has been associated with PIRx (Schmidt et al. 1998).

The odds of having PIRx and PIRx-severe were lower among residents who had communication problems. Residents with communication problems in general took fewer drugs; they might have trouble communicating their health needs to receive appropriate care, thus avoiding PIRx exposure. The problem of underuse of beneficial therapies had been identified in the management of a broad range of chronic conditions among the elderly (Rochon and Gurwitz 1999).

Consistent with previous studies (Piercoro, Browning, and Prince 2000; Spore et al. 1997), the average number of drugs taken monthly was associated with the risk of having PIRx and PIRx-severe. Polypharmacy (usually defined as taking nine or more drugs) is of special concern for the elderly because they have higher susceptibility to side effects and develop toxicity to certain drugs more easily than younger people. Polypharmacy should remain an important policy focus because of its apparent association with PIRx exposure.

The risk of having PIRx-severe was 50 percent higher for residents among the youngest age group (65 to 74 years old) than for those in the oldest age group (85 and older) (data are not shown in the table). (4) Similar to other studies (Beers et al. 1992; Schmidt et al. 1998), younger elderly residents generally had significantly higher risks of receiving PIRx. Perhaps residents aged 85 and older were seen as more fragile and received more prudent prescribing by physicians. Admission to NHs at younger ages also is less common and may suggest that these residents had more complicated health problems, making them more difficult to manage and vulnerable to PIRx.