Atropine as a Treatment of Diarrhea After Celiac Plexus Block

Abstract

To the Editor: We read with interest Chan's case report [1]. We were impressed by his thorough treatment of the patient, as well as the analysis of sympathetic blockade as the etiology of the patient's chronic diarrhea. We are interested in knowing whether Dr. Chan has explored the possibility of intravenous (IV) atropine treatment. Goodman and Gilman [2] point out that large therapeutic doses of atropine produce definite and prolonged inhibitory effects on the motor activity of the duodenum, jejunum, ileum, and colon through receptor blockade of the parasympathetic system. Additionally, they note that some diarrheal conditions respond to atropine, while others do not. After being treated with a nerve block to the brachial plexus, several patients at the University Pain Service of the Westchester County Medical Center have had adverse side effects of bronchoconstriction and difficulty breathing. After excluding other causes of bronchoconstriction, such as asthma or iatrogenic pneumothorax or allergic reaction to any of the drugs injected, we concluded that sympathetic blockade was the most likely etiology. This hypothesis was further supported by the finding that bronchoconstriction was relieved by atropine, 0.4 mg IV. Both diarrhea and bronchoconstriction can occur as the result of a regional parasympathetic predominance of the autonomic nervous system. A literature search revealed a case report of diarrhea resulting from autonomic dysfunction that responded to atropine after other drug therapies had failed. Coker et al. [3] presented a case report of a 25-yr-old man who had tested positive for human immunodeficiency virus for 6 yr. He had suffered from watery diarrhea and had lost 20 kg over a 2-yr period. Opportunistic infections and other known causes of diarrhea had been excluded. Additionally, control of the patient's diarrhea had been unsuccessful despite the administration of a range of antidiarrheal drugs that included octreotide. A test with 1.8 mg IV atropine slowed gastric emptying. The patient was further treated with an anticholinergic drug, propantheline bromide at a dose of 45 mg tid, which reduced the volume and frequency of stools. We believe that these data support a therapeutic trial of atropine or other atropine-like drugs in cases of diarrhea where autonomic dysfunction is the suspected cause and other drugs such as octreotide, clonidine, and loperamide have failed. Ralph Cataldo, DO Anesthesia Pain Service Westchester County Medical Center Valhalla, NY 10595 Mordecai Potash New York Medical College Valhalla, NY 10595