Levodopa ameliorated anorectal constipation in de novo Parkinson’s disease: The QL-GAT study

Abstract Background Gastrointestinal tract (GIT) dysfunction is common in Parkinson’s disease (PD) patients. However, it remains unclear whether levodopa affects GIT function in PD. Objective To perform an open study of levodopa’s effects on anorectal constipation in de novo PD patients by the quantitative lower-gastrointestinal autonomic test (QL-GAT). Methods Nineteen unselected de novo PD patients (10 men, 9 women; mean age, 66 years; mean duration of the disease, 2.2 years) were recruited for the study. Eighteen of the patients reported constipation. These patients were treated with 200/20 mg b.i.d. of levodopa/carbidopa for 3 months. Pre- and post-treatment, objective parameters in the QL-GAT that comprised the colonic transit time (CTT) and rectoanal videomanometry were obtained. Results Levodopa was well tolerated by all patients. There was a trend toward subjective improvements in bowel frequency and difficulty defecating. Levodopa did not significantly change CTT of the total colon or any segment of the colon. During rectal filling, levodopa significantly lessened the first sensation ( p