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October 18, 1976

Guaifenesin Effects on the Guaiac Test for Occult Blood

Author Affiliations

From the Division of Clinical Pharmacy of the College of Pharmacy (Drs Brown and Self and Messrs Taylor and Stargel) and the Section of Pulmonary Medicine of the Department of Medicine of the College of Medicine (Dr Boswell), the University of Tennessee, Memphis.

JAMA. 1976;236(16):1881. doi:10.1001/jama.1976.03270170047028

IT HAS been stated that guaifenesin will give a positive guaiac reaction.1 Although Ogburn and Craner2 disputed this claim, inadequate data were presented. We have investigated the effect of guaifenesin on the stool guaiac test in 31 healthy volunteers.

Subjects and Methods  All subjects in this study were selected on the basis of a negative stool guaiac test in a control situation 24 hours prior to the study. There were no smokers in the population investigated. Volunteers with a history of any underlying gastrointestinal pathologic conditions (eg, ulceration, gastritis, carcinoma) were not allowed to participate. Subjects were instructed to maintain a normal diet but not to partake of rare or raw meat, alcohol, or other drugs seven days prior to and during the study. The study population consisted of three women and 28 men between the ages of 22 and 31 years. An explanation of the nature of