Cimetadine as a preoperative medication to reduce the complications of aspiration of gastric contents.

In an effort to decrease gastric residual and acid content prior to operation and thus to decrease the risk of aspiration, a prospective clinical trial comparing three drugs was carried out. Eighty-four patients undergoing elective craniotomy for a space-occupying lesion were studied. Twenty-eight patients were premedicated with the anticholinergic atropine (0.01 mg/kg); 28 patients were administered the anticholinergic glycopyrrolate (0.005 mg/kg); and 28 patients were given three preoperative doses of cimetadine and no anticholinergic. Gastric acidity was elevated above pH 2.5 in 93% of those receiving cimetadine, in comparison to 54% for glycopyrrolate and 29% with atropine. In addition, the stomach was completely dry in 54% following cimetadine, and in only 25% and 11% following glycopyrrolate and atropine. Cimetadine is more effective as a preanesthetic agent than anticholinergic drugs in decreasing gastric residual and acid content, and essentially eliminates the risk of aspiration.