The delayed adverse reactions of low osmolar contrast media.

A computer scale survey to inspect the occurrence of delayed symptoms (adverse reactions) associated with the intravenous injection of low osmolar contrast medium (LOCM) was carried out. Of the recovered 1070 questionnaires, 290 had the delayed symptoms. Excluding 59 patients having the same symptoms in the past one year without contact with the contrast medium, the overall incidence of the delayed adverse reaction is 22.8% (231/1011). The delayed symptoms include arm pain (6.0%), headache (3.6%), itching (2.3%), rash (1.5%), general fatigue (1.4%), gastrointestinal symptoms, etc. Though the chi-square test had shown significance of the occurrence of the delayed symptoms for the group with a past history of drug allergy and nasal allergy (p less than 0.05), the delayed symptoms were mainly distributed in the middle-aged female to indicate that the sexuality is the cause of the foresaid significance. Furthermore, the incidence of the objective delayed symptoms such as rash in the group who had accepted more than two examinations is lower than the incidence in the group who accepted only one examination in the survey period. The disagreement to the fact that the repeated usage of the contrast medium is the risk factor to increase the incidence of the adverse reactions indicates the contrast medium may not be the only cause for the occurrence of the delayed symptoms, e.g. other factors such as sexual and psychological factors etc. may play a more important role than the contrast medium under this type of survey.