Clinical implications of the presence of drug residues in food.

Untoward clinical effects in man of drugs or chemicals as food residues might occur from direct pharmacological action, stimulation of hypersensitivity, or effects on cell regulatory processes. Antimicrobial residues might also influence the normal bacterial microflora of the skin, mucous membranes, and gastromintestinal tract. No direct evidence exists to incriminate antimicrobial drug food residues in any of these events. The permissible residues of antimicrobial substances are so low and the assay procedures for detecting them so sensitive that adequate surveillance should preclude harmful effects in man from these agents. Problems still remain with respect to potential carcinogenicity of drugs and chemicals as food residues.