Abstract: Objective To analyze the effect of compound paracetamol tablets on plasma concentrations of risperidone in patients with schizophrenia who had a cold. Methods The clinical data of 424 cold patients who received risperidone treatment in a hospital between June 1, 2019 and June 1, 2024 was retrospectively collected, 296 of whom had taken compound paracetamol alkane tablets while they had a cold and were assigned to the medication group. The rest of the patients who received no medication for their cold were included in the non-intervention group. The effects of colds and compound paracetamol tablets on high-level plasma concentrations of risperidone in these patients were analyzed. Results ①In the medication group, plasma concentrations of risperidone increased to varying degrees compared with the baseline (P <0.05).②The plasma concentrations of risperidone in both groups increased to varying extents compared with the baseline (P <0.05), especially in the medication group (P <0.05).③There was little difference in levels of risperidone between male and female patients ages 18 to 45 in the medication group (P >0.05), but the plasma concentrations of risperidone were higher in females than in males aged 46 to 60 (P <0.05).④There was no significant difference in the incidence of adverse reactions related to risperidone between the two groups (P >0.05), but more than half of the cases of adverse reactions occurred among patients with high concentrations of risperidone. Conclusion Colds may increase the plasma concentration of risperidone in patients with schizophrenia. Using compound paracetamol tablets can make matters worse among patients with a cold. It is recommended that blood concentrations be monitored and medication plans be adjusted when necessary.

Key words: Compound Paracetamol Tablets, Risperidone, Schizophrenia, Cold, Plasma Concentration