Drug adherence in Parkinson`s disease

Physicians modify drug schedules in response to their patients` clinical responses. Failure to relieve patients` symptoms or the emergence of drug-related side effects may reflect nonadherence to a prescribed drug schedule rather than incorrect therapeutic physician decisions. Using a medication questionnaire and a computerized medication event monitoring system (MEMS) to monitor medication use, nonadherence of drug use was examined in subjects with Parkinson`s disease (PD). We report that prescription nonadherence in PD subjects was common and approximated that reported in other chronic diseases. During a 28-day observation period, only 4 of 39 subjects had complete schedule adherence, i.e., no missed, extra, or mistimed doses. Using a questionnaire, 24.3% of subjects acknowledged missing any doses but the computerized MEMS recorded that 51.3% of subjects missed at least one dose per week and 20.5% of subjects missed three or more doses per week. Mistiming of doses was admitted by 73% of subjects but 82.1% had recorded mistimed doses. Of multiple sociodemographic and disease-related items examined, only gender and level of education were statistically related to nonadherence.