[Aminopenicillin crystalluria: identification by infrared spectrophotometry].

Renal stones and crystalluria can be characterized unambiguously by global physical methods. The authors report four cases of crystalluria induced by aminopenicillin (ampicillin and amoxicillin). Identification of these drug-induced crystalluria was made by high-pressure liquid chromatography and infrared spectrophotometry. The physico-chemical data and infrared absorption characteristics can give us diagnostic for various forms of ampicillin and amoxicillin.