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36 GastRointestinal endOSCOPY Editor WILLIAM S. HAUBRICH, M.D. Assistant Editor ElLEN C. SHANNON, M.A. Business Manager DONALD W. TRUMAN, A.B. Ed itor for Abstracts BERNARD M. SCHUMAN, M.D. Address all correspondence to the Editor Scripps Clinic & Research Foundation 476 Prospect Street La Jolla, California 92037 Editorial Consultants WILLIAM H. MAHOOD, M.D. Philadelphia G. GORDON McHARDY, M.D. New Orleans JOHN F. MORRISSEY, M.D. Madison VERNON M. SMITH, M.D. Baltimore BENJAMIN H. SULLIVAN, Jr, M.D. Cleveland FRANCISCO VILARDElL, M.D. Barcelona Advertising Committee J. ALFRED RIDER, M.D., Chairman 350 Parnassus Street San Francisco, California 94117 FRANCIS J. OWENS, M.D. Cleveland EUGENE A. GELZAYD, M.D. Southfield PAUL A. KANTOWITZ, M.D. Cambridge MARSHAll S. SPARBERG, M.D. Chicago MURREl H. KAPLAN, M.D. New Orleans JULIUS WENGER, M.D. Atlanta ARTHUR P. KLOTZ, M.D. Chairman, AISIGIE Budget and Finance Committee Kansas City, Kansas Antibiotics and the bowel The ideal antibiotic agent-specifically lethal to infecting pathogens and totally harmless to the host-has yet to be developed. At the same time, it is a tribute to the genius of microbiologists and pharmacologists that we have been provided with a variety of antibiotic agents as selectively beneficial and minimally detrimental as they are. Adverse effects, when they occur, generally have been of3 types: the stimulation of injurious immune responses, both humoral and cell-mediated; the disturbance of commensal ecology, permitting the emergence of superinfection; and the de- struction or impairment of the cellular tissues of the host, exemplified by leucopenia, aplastic anemia, or pan- cytopenia. Elsewhere in this issue, DeFord and his colleagues de- scribe the endoscopic characteristics of injury to intestinal mucosa wrought by lincomycin (Lincocin) and its closely related derivative, clindamycin (Cleocin). Bowel reaction to these agents has been the subject of a number of recent reports (e.g., Gastroenterology 66:1137, 1974). It is appar- ent that this reaction ranges in a broad spectrum from transient, annoying diarrhea to severe, protracted, pseudomembranous, ulcerative enteritis. The recently reported experience with lincomycin and clindamycin revives the mooted question of "antibiotic diarrhea." That certain antibiotic agents in susceptible pa- tients disturb the bowel there can be no doubt. The exact relationship between antibiotic and bowel and the mechanism of enteric disturbance remain, as before, un- clear (Brit Med 1 4:402, 1968; lAMA 203:210, 1968). Three possible mechanisms come to mind: (a) the physiochemical nature of the antibiotic itself may be nonspecifically irritating, e.g., an injurious pH; (b) the antibiotic effect on commensal organisms may foster the rise of a new and supervening infection (the wider the spectrum of antibiotic activity, the more likely this is to occur); and (c) an antibiotic effect directly on the cells of the intestinal mucosa. There has been no evidence thus far that lincomycin or clindamycin exert any nonspecific physicochemical effect on topical application. Neither lincomycin nor clindamycin are broad-spectrum antibiotics, and neither is known to have any particular effect on the normal bowel flora. Superinfection has not been a common feature of lincomy- cin enteritis, yet injury to the mucosa can be devastating. Why? Both lincomycin and its derivative clindamycin belong to the class of drugs that exerts an antibiotic effect by interfer- ing with protein synthesis, probably at a molecular level. It is reasonable to assume that this same effect may be exerted on the rapidly multiplying, rapidly synthesizing intestinal epithelial cells. If this interference results in actual epithelial cell destruction, and inhibits epithelial cell regeneration, then an ulcerative, pseudomembranous, inflammatory reac- tion might ensue. Perhaps a curious and perceptive endos- copist will furnish evidence confirming or refuting this hypothesis. We are grateful to DeFord and his associates for helping us recognize this antibiotic injury for what it is. Hopefully we are alerted and will avoid mistaking this antibiotic injury for idiopathic inflammatory bowel disease. Better yet, of course, is reducing the likelihood of this sort of injury by a policy of scrupulous discrimination in the prescription on potentially injurious antibiotic agents.
