Antipsychotic medication adherence: is there a difference between typical and atypical agents?

Area of Science:

• Psychiatry
• Pharmacology
• Health Services Research

Background:

• Medication adherence is crucial for managing chronic conditions like psychosis.
• Typical and atypical antipsychotics represent different classes of medications used to treat psychiatric disorders.
• Understanding adherence patterns across these drug classes is essential for optimizing patient outcomes.

Purpose of the Study:

• To compare medication adherence between outpatient veterans receiving typical versus atypical antipsychotic medications.
• To quantify adherence differences using refill records and calculate specific adherence metrics.

Main Methods:

• Pharmacy refill records were analyzed for consecutive patients prescribed haloperidol, perphenazine, risperidone, olanzapine, or quetiapine.
• Adherence was assessed over 12 months using the cumulative mean gap ratio and compliant fill rate.
• A hospital policy required failure on two typical antipsychotics before initiating atypical agents.

Main Results:

• Atypical antipsychotic users demonstrated moderately higher adherence rates at 6 and 12 months compared to typical antipsychotic users.
• At 12 months, the cumulative mean gap ratio was 14.1% for atypical versus 23.2% for typical antipsychotics.
• Compliant fill rates at 12 months were 54.9% for atypical and 50.1% for typical antipsychotics.

Conclusions:

• Patients receiving atypical antipsychotics exhibited improved medication adherence compared to those on typical antipsychotics.
• Despite higher adherence with atypical agents, interventions to further enhance medication adherence are necessary for all patients.
• These findings highlight the need for continued focus on adherence support in psychiatric pharmacotherapy.