Adherence to antipsychotic and nonpsychiatric medications in middle-aged and older patients with psychotic disorders

Abstract

Objective: The prevalence and consequences of nonadherence to antipsychotic medications in schizophrenia and related psychotic disorders have been well described; however, little is known about adherence to medications for nonpsychiatric conditions in patients with psychotic disorders. We wished to determine medication adherence in nondemented middle-aged and older Veterans Affairs outpatients with schizophrenia or other psychotic disorders who had been prescribed oral medications for hypertension, hyperlipidemia, or diabetes.

Methods: Medication adherence was assessed by review of medication fill records for 76 patients aged 40 years and older who had been prescribed an oral antipsychotic in addition to an oral agent for hypertension (N = 60), hyperlipidemia (N = 28), or diabetes (N = 24). Up to 12 months of therapy was reviewed, and a compliant fill rate (the number of adherent fills in proportion to the total number of prescription fills) and cumulative mean gap ratio (the number of days when medication was unavailable in relation to the total number of days) were calculated for each medication.

Results: The 12-month mean compliant fill rates for antipsychotics, antihypertensives, antihyperlipidemics, and antidiabetics ranged from 52% to 64%. Nonpsychiatric medication adherence rates were similar in patients on typical vs. atypical antipsychotics and did not correlate significantly with antipsychotic adherence rates.

Conclusions: Nonadherence rates were found to be equally problematic for both antipsychotic and nonpsychiatric medications in middle-aged and older patients with psychotic disorders. Interventions to improve adherence to both antipsychotic and nonpsychiatric medications are needed.