Treatment Adherence in Schizophrenia: Which Antipsychotic Is Best?

Schizophrenia is a complex and life-long mental disorder characterized by distortions in thinking and behavior.¹ Although schizophrenia only affects 1.1% of the United States population, the cost of the disease is very high due to its burden on patients, families, as well as the general population. Treatment for schizophrenia includes both first-generation antipsychotic (FGA) and second-generation antipsychotic (SGA) medications. Both oral antipsychotics (OAP) and long-acting injectable therapies (LAI) are available for each generation, giving patients many different treatment options.

Despite many choices of therapy, poor adherence to treatment is a key issue for schizophrenic patients.¹ Poor adherence to antipsychotics (AP) often leads to psychotic episodes and disease relapse, making it imperative for healthcare professionals to recognize the most effective treatment option for a particular patient. Unfortunately, evidence comparing the effectiveness of LAI therapy and OAP is mixed, making it difficult for clinicians to choose the best treatment option for a patient.

A recent study published by Pilon et al examined the impact of LAI therapy compared to OAP in schizophrenic patients in a real-world setting.¹ In this retrospective, longitudinal, cohort study, medical as well as pharmacy claims of Medicaid beneficiaries were analyzed between January 2009 and March 2015. During the study, adult patients with at least two diagnoses for schizophrenia that were initiated on an FGA-LAI, SGA-LAI, or OAP “index” medication were evaluated over a 12-month period. Treatment outcomes included medication adherence and persistence as well as patterns of treatment, and are detailed in Table 1. 

The study included a total of 23,776 patients.¹ Of these patients, 86.1% were in the OAP group, 4.6% were in the FGA-LAI group, and 9.3% were in the SGA-LAI group.  Of the patients initiated on an OAP, 78.7% received treatment with a SGA. The study authors noted that “on an average, patients initiated on OAP had a higher baseline (ie, pre-index date) comorbidity burden to FGA or SGA-LAI patients.”  

Results of the study found various differences in treatment patterns for patients initiated on FGA-LAI compared to OAP.¹ A reduction in psychiatric medication use during the follow-up period was seen in FGA-LAI patients compared to OAP patients (81.1% vs 95.0%, respectively; P<0.001). Although AP use did not significantly differ between the two groups, use of adjunctive therapy was lower in the FGA-LAI group versus OAP group (69.5% vs 89.8%, respectively; P<0.001). Additionally, psychiatric polypharmacy was reduced in FGA-LAI patients compared to OAP patients (50.1% vs 70.2%, respectively; P<0.001).