The aim of this study was to investigate the relationship between metabolic factors and use of selective serotonin reuptake inhibitors (SSRIs) combined with olanzapine, quetiapine or risperidone.
Data from a cross-sectional study on 1301 patients with schizophrenia or bipolar disorder were analyzed. The main outcome variables were levels of total cholesterol, low – and high-density lipoprotein (LDL and HDL) cholesterol, triglycerides and glucose.
One 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). When combined with risperidone, no such effects were revealed. No clear-cut effects were seen for HDL-cholesterol, triglycerides and glucose.
The findings indicate only minor deteriorations of metabolic variables associated with treatment with an SSRI in addition to olanzapine and quetiapine, but not risperidone. These results provide new insight in the cardiovascular risk profile associated with concomitant drug treatment in patients with severe mental illness, and suggest that SSRIs can be combined with anti-psychotics without a clinically significant increase of adverse metabolic effects.
Co-author Dr. Ole Andreassen has received speakers’ honoraria from GSK, Lundbeck and Otsuka.