Use of bethanechol chloride to increase available ultrafiltration in CAPD

Reabsorption of peritoneal dialysis fluid during the prolonged dwell time of continuous ambulatory peritoneal dialysis (CAPD) reduces the efficiency of ultrafiltration and sacrifices effective dialysis adequacy. Studies by Nolph indicate a predominant role of lymphatics in this fluid loss. Khanna has reported that lymphatic flow may be influenced by acetylcholine. This study was designed to determine if bethanechol chloride (BC) would increase the availability of drained volume during CAPD. Nine patients were studied, including 7 patients who exhibited inadequate ultrafiltration. During a 5-day control period, total dialysate drained volume was collected and a standard peritoneal equilibration test (PET) performed. This was followed by a corresponding 5-day test period in which BC (mean dose 0.27 +/- 0.13 mg/kg/day) was administered orally. Drained volume during the control standard 4-hr PET was 1996.68 +/- 279.87 mL. The result for the test period was 2363.33 +/- 321.13 mL (p < 0.05), indicating an 18.4% increase using BC. The PET indicated no change in transport of urea, creatinine, and glucose. In conclusion, the total drained volume can be effectively increased with a subsequent increase in metabolite clearance using BC. Patients exhibiting inadequate ultrafiltration were able to be maintained on CAPD using this cholinergic drug.