Cefdinir is an extended-spectrum, third-generation cephalosporin that is frequently used for otitis media. There are reports in the pediatric literature of patients having red or maroon-colored stool while taking this medication.1,2 According to its manufacturer, this occurs when cefdinir combines with iron to form a precipitate that gives stool a characteristic discoloration. This usually occurs in infants who are receiving iron-containing infant formulas (Figure). These patients have no associated gastrointestinal symptoms, and their stools are guaiac-negative. The stool color returns to normal upon cessation of cefdinir.
Many gastroenterologists whose practice is exclusive to adult patients are not aware of this effect of cefdinir. When faced with a patient who has guaiac-negative red stool, inquiry should be made about exposure to antibiotics and other agents. The Table lists substances that cause feces discoloration that are not usually associated with gastrointestinal bleeding. Recognition of the benign effect of various substances on stool color may prevent unnecessary alarm and costly medical evaluations.
References
1. Lancaster J, Sylvia LM, Schainker E. Nonbloody, red stools from coadministration of cefdinir and iron-supplemented infant formulas. Pharmacotherapy. 2008;28:678-681.
2. Graves R, Weaver SP. Cefdinir-associated “bloody stools” in an infant. J Am Board Fam Med. 2008;21:246-248.
Meredith C. Roath, MD
Jack A. Di Palma, MD, FACG
Division of Gastroenterology, University of South Alabama College of Medicine, Mobile, Alabama
Address correspondence to: Dr. Jack A. Di Palma, Director, Division of Gastroenterology, USA Pavilion at Infirmary West, 5600 Girby Road, Mobile, AL 36693; Tel: 251-660-5555; Fax: 251-660-5558; E-mail: jdipalma@usouthal.edu