Metabolic risk factors in schizophrenia and bipolar disorder: The effect of comedication with selective serotonin reuptake inhibitors and antipsychotics

Abstract

AbstractBackgroundThe aim of this observational study was to investigate the relationship between metabolic factors and use of selective serotonin reuptake inhibitors (SSRIs) combined with olanzapine, quetiapine or risperidone.MethodsData from the Norwegian Thematically Organized Psychosis study, a cross-sectional study on 1301 patients with schizophrenia (n=868) or bipolar disorder (n=433), were analyzed. As exposure variables in the linear regression model were included the dose or serum concentration of SSRIs (n=280) and of olanzapine (n=398), quetiapine (n=234) or risperidone (n=128). The main outcome variables were levels of total cholesterol, low and high density lipoprotein (LDL and HDL) cholesterol, triglycerides and glucose.ResultsOne defined daily dose (DDD) per day of an SSRI in addition to olanzapine was associated with an increase in total cholesterol of 0.16 (CI 0.01 to 0.32) mmol/L (P=0.042) and an increase in LDL-cholesterol of 0.17 (CI 0.02 to 0.31) mmol/L (P=0.022). An SSRI serum concentration in the middle of the reference interval in addition to quetiapine was associated with an increase in total cholesterol of 0.39 (CI 0.10 to 0.68) mmol/L (P=0.011) and an increase in LDL-cholesterol of 0.29 (0.02 to 0.56) mmol/L (P=0.037). There were no such effects when combined with risperidone.ConclusionsThe findings indicate only minor deteriorations of metabolic variables associated with treatment with an SSRI in addition to olanzapine and quetiapine, and none when combined with risperidone. These results suggest that SSRIs can be used in combination with antipsychotics, and that the possible increase in cardiovascular risk is negligible.