Impact of second-generation antipsychotics on the use of antiparkinson agents in nursing homes and assisted-living facilities.

BACKGROUND

It is not known whether the reduced risk of motor adverse effects with second-generation antipsychotics (SGAPs) translates into less use of antiparkinson drugs (APDs).

OBJECTIVE

This study sought to estimate national rates of concomitant prescribing of APDs and antipsychotic drugs among elderly Medicare beneficiaries without Parkinson's disease (PD) who were residing in institutional settings from 1997 to 2000, a period during which the use of SGAPs increased greatly.

METHODS

This was a retrospective, cross-sectional, descriptive analysis using the Medicare Current Beneficiary Survey database. The population of interest was residents of nursing homes (NHs) and assisted-living facilities (ALFs) who received concomitant antipsychotic drugs and APDs but did not have PD. The primary objective of the study was to estimate the prevalence of concomitant APD and antipsychotic drug use for each study year, by use of first-generation antipsychotics (FGAPs) and SGAPs in each setting. A secondary objective was to compare concomitant use of APDs and individual antipsychotic agents (ie, clozapine, risperidone, olanzapine, quetiapine, ziprasidone, haloperidol, and thioridazine). We computed population-level annual prevalence rates for APD use and tested for statistically significant differences in APD use between FGAPs and SGAPs at the 5% significance level.

RESULTS

In NH residents, concomitant use of APDs and antipsychotics decreased from 20.7% in 1997 to 9.0% in 2000 (P < 0.005). APD use in NH residents declined similarly among users of FGAPs (from 23.2% in 1997 to 13.3% in 2000; P < 0.005) and SGAPs (from 18.4% in 1997 to 8.1% in 2000; P < 0.005). In ALF residents, concomitant use of APDs and antipsychotics decreased from 24.5% in 1997 to 21.1% in 2000 (P < 0.005). ADP use in ALF residents receiving FGAPs decreased from 26.9% in 1997 to 24.2% in 2000 (P < 0.005); there was no significant change in ADP use among ALF residents receiving SGAPs (from 21.0% in 1997 to 21.7% in 2000).

CONCLUSIONS

These results provide the first nationally representative estimate of the concomitant use of APDs and antipsychotic drugs among older individuals in long-term care settings. The decrease in concomitant use of APDs and antipsychotics when SGAPs were used in NHs suggests an association between the use of SGAPs and a reduction in the prescribing cascade, in which one drug is used to treat the adverse effects of another. The results also suggest that some Medicare beneficiaries in ALFs may be continued on APDs despite changes in the prescribing of antipsychotic agents, implying a need for better medication-management practices in these institutions.