A Qualitative, Interview-based Study of Patient, Caregiver, and Prescriber Preferences for a Long-acting Injectable Antipsychotic Formulation Administered Once Every 2 Months for Schizophrenia or Bipolar I Disorder

The number of long-acting injectable (LAI) antipsychotic formulations approved for the treatment of schizophrenia (SCZ) or bipolar I disorder (BP-I) is increasing, with new dosing intervals becoming available. This qualitative study investigated patient, caregiver, and prescriber preferences for a hypothetical LAI administered once every 2 months.
In Europe and North America, single-person telephone interviews were conducted to explore LAI dosing preferences and factors influencing preferences for a 2-month dosing interval among people with SCZ or BP-I (stable patients treated with a once-monthly LAI), caregivers, and prescribers. Qualitative analysis software was used to code transcripts and identify themes.
In the SCZ sample, 27 patients, 16 caregivers, and 18 prescribers were interviewed; in the BP-I sample, 12 patients, 5 caregivers, and 5 prescribers were interviewed. Patients and caregivers described an ideal treatment as efficacious, with a decreased dosing frequency (versus once-monthly) and minimal/no side effects – which would mean more freedom and less disease burden. Views on an LAI with a 2-month dosing interval were generally positive. Patients/caregivers felt they would spend less time thinking about/attending appointments; a concern was the medication wearing off. Prescribers thought a 2-month dosing interval may allow patients to feel stable for longer; a concern was a loss of dosing control. Prescribers were open to recommending an LAI with a 2-month dosing interval to stable patients desiring reduced dosing frequency.
An LAI with a 2-month dosing interval may be generally accepted for treatment of SCZ or BP-I; critical factors for adoption are effectiveness and duration of efficacy.