Glaser B, Kraiem Z, Rotem M, Gonda M, Bernheim J, Sheinfeld M
J Clin Endocrinol Metab. 1984 Nov;59(5):993-7. doi: 10.1210/jcem-59-5-993.
To evaluate the acute effect of histamine H2-receptor blockade with cimetidine on PTH concentrations and its endogenous biological activity, we studied the effect of iv administration of cimetidine (50-mg bolus followed by 500 mg/60 min infusion) in normal subjects and patients with primary and secondary hyperparathyroidism. No significant changes in serum concentrations of calcium, phosphate, or immunoreactive C-terminal PTH were found in any group. However, the control group had decreased calciuria, increased phosphaturia, and decreased tubular reabsorption of phosphate, while the primary hyperparathyroid group had increased phosphaturia, increased nephrogenous cAMP excretion, and decreased tubular reabsorption of phosphate. In both of these groups, the finding suggest an increase in PTH-like biological activity. These findings suggest that cimetidine is not useful in the diagnosis or medical management of hyperparathyroidism. In fact, the changes in renal calcium and phosphorous excretion indicative of PTH-like biological activity along with a decrease in creatinine clearance in the primary hyperparathyroid group suggest a relative contraindication to the use of this drug in these patients.
为评估西咪替丁阻断组胺H2受体对甲状旁腺激素（PTH）浓度及其内源性生物活性的急性影响，我们研究了静脉注射西咪替丁（先静脉推注50 mg，随后以500 mg/60分钟的速度输注）对正常受试者以及原发性和继发性甲状旁腺功能亢进患者的影响。任何一组的血清钙、磷或免疫反应性C末端PTH浓度均未发现显著变化。然而，对照组尿钙减少、尿磷增加且肾小管对磷的重吸收减少，而原发性甲状旁腺功能亢进组尿磷增加、肾源性环磷酸腺苷（cAMP）排泄增加且肾小管对磷的重吸收减少。在这两组中，这些发现提示PTH样生物活性增加。这些结果表明西咪替丁对甲状旁腺功能亢进的诊断或药物治疗并无用处。事实上，原发性甲状旁腺功能亢进组中提示PTH样生物活性的肾钙和磷排泄变化以及肌酐清除率降低表明，在此类患者中使用该药物存在相对禁忌证。
