Adverse general reactions to high doses of methylglucamine-based contrast media

In 66 successive patients having parathyroid venous sampling, 29 received methylglucamine iothalamate, 29 received sodium metrizoate with calcium, magnesium and methylglucamine supplements, two received methylglucamine diatrizoate, and six received sodium iothalamate in an average dose of 85 g of iodine. There were ten reactions of at least an intermediate grade, nine with methylglucamine iothalamate and one with methylglucamine diatrizoate. Possible predisposing factors were compared but the only significant factor, apart from the type of contrast agent, was age. We suggest that in high-dose examinations in patients over 50 years of age sodium salts should be used in preference to methylglucamine salts unless sensitive organs are directly perfused.