Antipsychotic Injections for Schizophrenia Linked to Decline in Hospital Readmissions

Daniel Greer, PharmD

Credit: Rutgers Ernest Mario School of Pharmacy

Antipsychotic injections are linked to a 75% reduction in 30-day rehospitalizations compared with other oral antipsychotics, according to a new Rutgers Health study.¹ The findings support the use of injections over daily pills for medical and financial reasons.

“Controlling symptoms to avoid hospitalization is even more important with schizophrenia than other conditions because each relapse makes the condition harder to treat going forward,” said lead investigator Daniel Greer, PharmD, a clinical assistant professor at the Rutgers Ernest Mario School of Pharmacy, in a press release.²

Although clinicians who follow standards of care for schizophrenia treatment already prescribe long-acting injections over daily oral medication, Greer pointed out how pills remain an acceptable treatment option. He added how patients may choose the pills over injections for insurance coverage or fear of needles.

Patients might choose pills over injections because some insurances may not cover long-acting antipsychotic injections because they cost more than oral treatments. However, in recent years more insurance have covered injections due to research demonstrating the treatment’s superior results.

In their single-center retrospective review, Greer and colleagues compared 30-day readmission rates for all patients with schizophrenia or schizoaffective disorder discharged from a single academic hospital from August 2019 – June 2022.1 As for secondary outcomes, the team assessed for chlorpromazine equivalent doses and use of anticholinergic medications.

“Thirty-day readmission rates are important to assess as they are a marker of patient outcomes and have reimbursement implications as well,” investigators wrote. “The Hospital Readmissions Reduction Program allows Medicare to reduce payment to hospitals with excess 30-day readmission rates.”

Patients were included if they were ≥ 18 years old, admitted to the psychiatric unit for schizophrenia/schizoaffective disorder, and discharged on antipsychotic medication. The average age was 40.3 years with 55.4% being male, and 32.9% being African American.

Among patients discharged with injections, 45.6% received aripiprazole lauroxil, 35% received haloperidol decanoate, 15.5% received paliperidone palmitate, 2.9% received aripiprazole, 1% received fluphenazine decanoate, and 1% received risperidone. As for patients discharged on oral medications, 27.5% received risperidone and 21.3% received olanzapine, as well as others receiving haloperidol, aripiprazole, clozapine, quetiapine, chlorpromazine, perphenazine, ziprasidone, and iloperidone.

More patients opted for the pills (70%) than the long-acting injections (30%) when discharged. The investigators noted, after 30 days, the readmission rate was 8.3% among patients who received pills and 1.9% among patients who received long-acting injections (P = .03; 95% confidence interval [CI], 1.05 – 20.02).

“I suspect the lower readmission rate that has been observed with long-acting injections has more to do with people forgetting to take a pill each and every day than with any inherent superiority of the injectable medication,” Greer said.² “Other studies on the use of antipsychotic medication have found that roughly three-fourths of patients do not take oral medications exactly as directed, and it’s much easier to get a shot every few months than it is to take a pill every day, even though the shot requires a trip to the doctor.”

As for the secondary outcomes, the chlorpromazine equivalent antipsychotic dose of patients on a long-acting injectable was 477.2 mg/DL versus the oral medication at 278.6 mg/DL (P < .001). Moreover, the prevalence of medications used to treat extrapyramidal symptoms was 22.3% for injectables and 30.8% for oral medication (P = .12).¹ Additionally, 64% of injectables were used during pharmaceutical company hospital inpatient free trial programs.

The team also found the prevalence of medications used to treat EPS was 22.3% with patients discharged with injections and 30.8% with patients discharged with pills (P = .12; 95% CI, 0.90 – 2.66). Many patients in both the injection and oral medication groups received benztropine. Investigators found no difference in the use of anticholinergic medications between 2 groups with similar adverse effects.

Limitations highlighted by the investigators included the retrospective chart review study design not allowing for randomization or controls—without this, patients who were more ill may have been more likely to receive an injection. Additionally, other biases could have existed since 64% of the injections were received through free trial programs, eliminating the cost. Other limitations included the smaller sample size due to the study being single-center and not accounting for injection dose changes.

“In conclusion, LAI antipsychotics showed a statistically significant reduction in 30-day rehospitalizations as compared with oral antipsychotics,” investigators wrote. “In addition, prescribers were comfortable utilizing medications obtained from free trial replacement programs, which can help offset the upfront cost while also not being billed to patients.”

^References

1. ^{Thaman P, Kulig CE, Greer D. Efficacy of Long-Acting Injectable Antipsychotics Versus Oral Antipsychotics in Preventing Psychiatric Rehospitalizations. J Clin Psychopharmacol. Published online January 17, 2024. doi:10.1097/JCP.0000000000001810}
2. ^{Antipsychotic Injections Linked To A Sharp Drop In Hospital Readmissions. EurekAlert! January 30, 2024. https://www.eurekalert.org/news-releases/1032827. Accessed January 31, 2024.}