Abstracts

Rationale: Elderly patients, especially those residing in nursing homes, have a greater number of co-morbidities and co-medications than adult patients. It is important to understand concurrent drug use and its potential impact on an already at risk population. Diagnosis and co-medication data taken from a prospective, multi-arm nursing home study were evaluated in order to examine concomitant drug use (polypharmacy) in elderly nursing home residents taking one or more antiseizure drugs (ASDs).Methods: Elderly residents (> = 65 years) residing in a non-rehabilitative care facility were recruited from eight nursing homes for a prospective study involving 4 visits over a 4 to 6 month period. Residents receiving a stable dose of an AED were included (phenytoin, levetiracetam, gabapentin, lamotrigine). Retrospective data pertaining to seizure frequency, diagnoses and co-medications, adverse event history, and demographics were abstracted from the resident’s file. Charlson scores were computed for each resident and co-medications were categorized according to the pharmacologic-therapeutic classification developed by the American Society of Health-System Pharmacists (AHSP). Statistical significance was determined using Pearson correlation coefficient. A p value < 0.05 was considered significant. Correlation between the number of scheduled co-medications, drug class, Beers list agents, and Charlson scores were determined. Only regularly administered co-medications abstracted at each participants first visit, as well as those that could be classified according to AHFS were included in this analysis.Results: The average age of each participant was approximately 78 years (60 years = low, 97 years = high). Data available for 124 elderly nursing home residents (79 women, 43 men, 2 unknown) revealed use of 169 unique drug therapies, totaling 1,136 therapies. Of these, 151 (13.3%) were defined as potentially inappropriate medications (PIMs), as determined by the Beers criteria. The use of at least one PIM (4 = high, 0 = low) was present in 88 residents (71%). Co-medication counts were lowest in the youngest cohort (< 65 years) and highest in the oldest (≥ 85 years). On average, male residents were prescribed 8.3 co-medications (including 1.2 PIMs), whereas women were prescribed 10.3 co-medications (including 1.4 PIMs). The highest incidence of polypharmacy was seen in the oldest cohort for both male and female residents. The number of per-resident co-medications (R = 0.35, p < 0.001), as well as the number of per-resident drug classes (R = 0.38, p < 0.001), correlated positively with Charlson scores; however, the number of per-resident PIMs were not (R = 0.17, p = 0.07) significantly correlated.Conclusions: Elderly nursing home residents received an average of 10 co-medications in addition to their regularly administered ASDs. A majority of these patients also received at least one drug recognized as potentially inappropriate. A higher number of co-medications correlated positively with an increased Charlson score, a predictor of short-term mortality for this population.