Xingqi Daozhi Decoction for Antipsychotic-Induced Constipation

Antipsychotic medications are widely used to treat schizophrenia but may cause constipation, which can lead to abdominal discomfort, reduced quality of life, and poor treatment adherence. Xingqi Daozhi Decoction is a traditional Chinese medicine formula used to relieve constipation associated with qi stagnation. This study aims to evaluate the effectiveness and safety of Xingqi Daozhi Decoction for antipsychotic-induced constipation with a qi stagnation pattern. This is a single-center, randomized, double-blind, placebo-controlled exploratory study. A total of 46 participants with schizophrenia who developed constipation after taking antipsychotic medications will be enrolled. Participants will be randomly assigned to receive either Xingqi Daozhi Decoction granules or matching placebo granules twice daily for 8 weeks. Neither the participants nor the treating clinicians and outcome assessors will know the treatment assignment during the study. Participants will be evaluated regularly during treatment. The study will assess changes in bowel movements, constipation symptoms, constipation-related quality of life, and treatment safety. Participants will also undergo routine clinical and laboratory safety assessments, and adverse events will be recorded throughout the study. The primary outcome focuses on the proportion of participants who achieve an improvement in complete spontaneous bowel movements during treatment.

Inclusion Criteria: Meets the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnostic criteria for schizophrenia. Positive and Negative Syndrome Scale (PANSS) total score ≤95, with a PANSS negative symptom subscale score ≤28. Meets the Rome IV diagnostic criteria for functional constipation with a qi stagnation pattern. Aged 18 to 65 years. Has at least a junior high school education and is able to complete self-report questionnaires. Has not used other medications known to cause constipation within the past 3 months. Has had no history of constipation within the past 2 years and no previous gastrointestinal disease. Developed constipation after initiation of antipsychotic medication. Exclusion Criteria: Meets DSM-5 diagnostic criteria for any psychiatric disorder other than schizophrenia. Is unable to maintain a normal diet because of psychiatric symptoms, or requires a special diet such as a diabetic diet, soft diet, liquid diet, fasting, or restriction of oral intake due to individual clinical circumstances. Uses other medications that may cause or aggravate constipation. Has had constipation within the past 2 years or has a history of gastrointestinal disease. Has lactose intolerance. Has clinically significant medical conditions, including diabetes mellitus, hypothyroidism, connective tissue disease, or other significant physical illnesses. Is pregnant, planning pregnancy in the near future, or breastfeeding.