Adenosine modulators and calcium channel blockers as add-on treatment for schizophrenia

Relapses remain common among individuals with schizophrenia indicating a need for improved treatments. Creating a completely new drug molecule is expensive and time consuming, and therefore drug repurposing should be considered. Aim of this study was to investigate the risk of psychiatric rehospitalization associated with use of adenosine modulators (AMs) and calcium channel blockers (CCBs) in schizophrenia. Individuals diagnosed with schizophrenia (N = 61,889) in inpatient care between 1972–2014 in Finland were included. The follow-up lasted from 1996 to 2017. Main exposures were use of AMs (allopurinol and dipyridamole) and CCBs (dihydropyridines, diltiazem, and verapamil). Thiazide diuretics were used as a negative control. Within-individual models in stratified Cox regression were used and adjusted hazard ratios (HR) with 95% confidence intervals (CIs) are reported. Use of AMs was associated with a reduced risk of psychiatric rehospitalization on drug class level (HR 0.74, 95% CI 0.65–0.84, P < 0.0001), as well as on the level of individual drugs (allopurinol HR 0.82, 95% CI 0.70–0.97, P = 0.02; dipyridamole HR 0.65, 95% CI 0.55–0.77, P < 0.0001). Use of CCBs was associated with a reduced risk of psychiatric rehospitalization on drug class level (HR 0.81, 95% CI 0.77–0.86, P < 0.0001). From the different CCBs, only exposure to dihydropyridines was associated with a reduced risk (HR 0.79, 95% CI 0.74–0.84, P < 0.0001). No effect was observed for the negative control, thiazide diuretics (HR 0.96, 0.90–1.02, P = 0.20). The effects of dipyridamole and dihydropyridines were more pronounced among younger persons and combination of AMs, and CCBs was associated with a lower risk than either drug class as monotherapy. These results indicate a need for randomized controlled trials of these drugs.

M124. ASSOCIATION OF CHRONIC PHYSICAL MULTIMORBIDITY WITH THE EFFICACY OF TREATMENT IN DIFFERENT SCHIZOPHRENIA SPECTRUM DISORDERS

Background Patients with schizophrenia spectrum disorders (SSD) have higher prevalence of chronic physical illness (CPI) and a substantially reduced life expectancy compared with the general population. Despite the increasing amount of research in this area, the effect on psychiatric treatment outcome is still not clear. Some research reported significant associations between several CPIs and different SSD treatment outcomes, whereas the remaining study did not. The objective of the current study is to assess differences in the association of the number of CPI with the overall number of psychiatric rehospitalization in specific SSD diagnosis. Methods We conducted a cross-sectional study of 354 patients diagnosed with SSD (ICD10): 135 schizophrenia, 71 acute and transient psychotic disorder, 57 schizoaffective disorder, 68 unspecified unorganic psychosis, 23 other (persistent delusional disorder, schizotypal disorder). The primary outcome was the association of the number of CPI with the number of psychiatric rehospitalization since the diagnosis, as the surrogate outcome for the treatment success, adjusted for the time from diagnosis, age, and gender of participants. Results Mean number of CPI adjusted for the time from diagnosis, age, and gender was not significantly nor clinically relevantly different between particular SSD diagnosis (F(5,345)=0.70; p=0.620). It was 1.7 in schizophrenia, 1.5 in acute and transient psychotic disorder, 1.4 in schizoaffective disorder, 1.8 in unspecified unorganic psychosis, 1.0 in persistent delusional disorder and 1.9 in schizotypal disorder. The mean number of CPI adjusted for the same three potential confounders was significantly different between particular SSD diagnosis (F(5,345)=2.78; p=0.018). It was 6.7 in schizophrenia, 3.8 in acute and transient psychotic disorder, 7.3 in schizoaffective disorder, 4.8 in unspecified unorganic psychosis. However, the association of the number of CPI with the psychiatric rehospitalizations, adjusted for the previously stated three confounders, was significant and clinically relevant only in participants diagnosed with schizophrenia. In these participants, an increase of one CPI was associated with the 2.3 (95% CI 1.2 to 3.5) more psychiatric rehospitalizations (p&lt;0.001). In participants diagnosed with other specific SSD the association of the number of CPI was not significantly associated with the number of psychiatric rehospitalizations. Moreover, on this particular sample level, it was negative, meaning that more CPI was associated with the lower number of psychiatric rehospitalization in all other SSD except in the case of unspecified nonorganic psychosis. Discussion In this cross-sectional study, we observed that the hypothesis of the effect of the number of CPI on the SSD treatment outcomes is valid only in the case of schizophrenia. Further research is needed to clarify whether additional psychological distress is related to the additional burden of multimorbidity.

Differences in the Effectiveness of Long-Acting Injection and Orally Administered Antipsychotics in Reducing Rehospitalization among Patients with Schizophrenia Receiving Home Care Services

The current study explored the differences in the effectiveness of first and second generation long-acting injections and orally administered antipsychotics in reducing the rehospitalization rate among patients with schizophrenia receiving home care services in a medical center in Southern Taiwan. Longitudinal data between 1 January 2006, and 31 December 2015, were collected retrospectively. Patients were classified into three treatment groups: First generation antipsychotic (FGA) long-acting injection (LAI), second generation antipsychotic long-acting injection (SGA) (LAI), and oral antipsychotics. The primary outcomes were the rehospitalization rate and the follow-up time (duration of receiving home care services) until psychiatric rehospitalization. A total of 78 patients with schizophrenia were recruited. The average observation time was about 40 months. The oral treatment group tended to be older with a higher number of female patients and a lower level of education. The FGA treatment group tended to have a higher frequency and duration of hospitalization before receiving home care services. We found no significant differences in the follow-up time or psychiatric rehospitalization rate after receiving home care services among the three treatment groups. We propose that oral and LAI antipsychotics were equally effective when patients received home care services. Our results can serve as a reference for the choice of treatment for patients with schizophrenia in a home care program.