Cocaine use in individuals with schizophrenia: impact on doses of discharge antipsychotic medications.

OBJECTIVES: Despite the high prevalence of cocaine use disorder in schizophrenia, the impact of cocaine on antipsychotic requirement has not been studied in this population. The aim of this study was to evaluate the effect of cocaine on doses of antipsychotic medication prescribed during periods of acute exacerbation of psychotic symptoms in individuals with schizophrenia.

METHODS: We reviewed the medical records of individuals with schizophrenia discharged from hospitals between 2008 and 2012. Student t tests and linear regression were used to compare doses of discharge antipsychotic medications (in chlorpromazine equivalents) between individuals with schizophrenia with cocaine positive urine drug test results (n = 180; age 42.71 ± 10.03 years) and individuals with schizophrenia with negative urine drug test results (n = 3194; age 38.49 ± 12.86 years).

RESULTS: Unadjusted analysis revealed that individuals with schizophrenia who tested positive for cocaine were discharged on lower doses of antipsychotic medication compared with those who tested negative (449.88 ± 2.12 vs 515.47 ± 2.16; P = 0.021). However, after adjusting for age, sex, race, and length of stay, the 2 groups did not differ on doses of discharge antipsychotic medication (geometric mean difference 7.41; CI: 7.62-12.30; P = 0.703).

CONCLUSIONS: Our preliminary result suggests that cocaine use does not impact significantly on the doses of antipsychotic medication prescribed during periods of acute exacerbation of psychosis in schizophrenia and individuals with schizophrenia with comorbid cocaine use disorder may require similar doses of antipsychotic medication as those without cocaine use disorder.