Hyperparathyroidism and HCTZ Use

Patient Selection and Monitoring

Patients with moderate-to-severe hypercalcemia (>12 mg/dL or symptomatic) should avoid HCTZ, according to the Praxis Medical Insights guideline 1
The American College of Physicians recommends starting with the lowest effective dose (12.5 mg/day) of HCTZ and monitoring serum calcium within 1-2 weeks of initiation and then every 3 months, as suggested by Praxis Medical Insights 1
HCTZ should be discontinued immediately if corrected calcium exceeds 10.2 mg/dL or rises >0.5 mg/dL from baseline, as per the Praxis Medical Insights guideline 1
The National Kidney Foundation suggests ensuring adequate hydration and avoiding concurrent calcium or vitamin D supplementation when using HCTZ in patients with hyperparathyroidism 1

In patients with X-linked hypophosphatemia, HCTZ is recommended to decrease hypercalciuria that occurs as a complication of phosphate and vitamin D therapy, according to Nature Reviews Nephrology 2, 3, 4