Effect of Paracetamol (n-acetyl-p-aminophenol) on Gastrointestinal Bleeding.

There is now ample evidence that the oral administration of aspirin leads to an increase in faecal blood loss in the majority of normal people. Some investigators (Lange, 1957; Alvarez and Summerskill 1958; Stubbe, Pietersen, and Van Heulen, 1962) have used chemical means of testing for occult blood in faeces, and others (Matsumoto and Grossman, 1959; Watson and Pierson, 1960; Holt, 1960; Scott, Porter, Lewis, and Dixon, 1961; Pierson, Holt, Watson, and Keating, 1961; Leonards, 1962; Wood, Harvey-Smith, and Dixon, 1962) have been able to show increased faecal blood loss in subjects whose erythrocytes had been labelled with Cr51. All agree that approximately 70% of normal people are susceptible, regardless of the method of study or of the population studied. Paracetamol (N-acetyl-p-aminophenol) has been suggested as a satisfactory substitute for aspirin (Batterman and Grossman, 1955; Cornely and Ritter, 1956; Newton and Tanner, 1956) but few workers have studied its effect on gastrointestinal blood loss. For this reason it was proposed to investigate paracetamol in relation to gastrointestinal bleeding using Cr51-labelled erythrocytes.