Cimetidine-induced PTH variations in uraemic patients evaluated with the aid of antisera against the terminal carboxyl and amino groups of the hormone molecule.

Eight uraemic patients on periodic haemodialysis were given 600 mg of cimetidine every day for 15 days. Parathyroid hormone levels before and at the end of this treatment were evaluated with two different antisera specific against the terminal -COOH and -NH2 groups of the hormone respectively. The results obtained suggest two things: though cimetidine may enhance PTH secretion, at the same time it accelerates peripheral disintegration of some of its metabolically active metabolites. It i therefore necessary to reconsider the possible use of cimetidine in the treatment of hyperparathyroidism associated with uraemia.