Neostigmine: safe and effective treatment for acute colonic pseudo-obstruction

Background: Ogilvie's syndrome, or acute colonic pseudo-obstruction, is a common and relatively dangerous condition. If left untreated, it may cause ischemic necrosis and colonic perforation, with a mortality rate as high as 50 percent. Neostigmine enhances excitatory parasympathetic activity by competing with acetylcholine for attachment to acetylcholinesterase at sites of cholinergic transmission and enhancing cholinergic action. We hypothesized that neostigmine would restore peristalsis in patients with acute colonic pseudo-obstruction.

Methods: Twenty-eight patients at Fletcher Allen Health Care and The Cleveland Clinic Foundation were treated for acute colonic pseudo-obstruction with neostigmine 2.5 mg IV over 3 minutes while being monitored with telemetry. Mechanical obstruction had been excluded.

Results: Complete clinical resolution of large bowel distention occurred in 26 of the 28 patients. Time to pass flatus varied from 30 seconds to 10 minutes after administration of neostigmine. No adverse effects or complications were noted. Of the two patients who did not resolve, one had a sigmoid Cancer that required resection and one patient died from multiorgan failure.

Conclusion: This study supports the theory that acute colonic pseudo-obstruction is the result of excessive parasympathetic suppression rather than sympathetic overactivity. We have shown that neostigmine is a safe and effective treatment for acute colonic pseudo-obstruction.