Effect of intraperitoneal neostigmine on peritoneal transport characteristics in CAPD

Lymphatics have been suggested to play a major role in the absorption of dialysate, which consequently affects the adequacy of peritoneal dialysis. Neostigmine has been found to decrease lymphatic absorption in rats, presumably by causing constriction of the lymphatic stomata. We investigated the effect of neostigmine on seven continuous ambulatory peritoneal dialysis (CAPD) patients in a prospective study. We performed modified peritoneal equilibration tests both with and without intraperitoneal neostigmine in a random order. Radiolabeled albumin (0.8 mg) was added to 2 liters of dialysate +/- 2.0 mg neostigmine. We evaluated ultrafiltration and creatinine, phosphate, and urea clearances. The dialysate bag and the peritoneum were scanned at the initiation and conclusion of the four-hour dwell period. We found no change in ultrafiltration, residual volumes, creatinine, phosphate and urea clearances, or albumin recovered. Of the seven patients exposed to neostigmine, four had diarrhea, abdominal cramps, nausea, and vomiting. In conclusion, we found that 2 mg i.p. neostigmine did cause significant side-effects and did not alter transport characteristics in CAPD patients.