Is Parenteral Bisphosphonate Therapy Safe and Effective in the Management of Severe Primary Hyperparathyroidism Prior to Parathyroidectomy?

Primary hyperparathyroidism induced hypercalcaemic crisis is defined as an albumin- adjusted calcium ≥3.50 mmol/L, occurring in the presence of organ dysfunction. This endocrine emergency requires medical optimisation prior to urgent parathyroidectomy. However, few guidelines exist on the most appropriate course of treatment, including the use of preoperative bisphosphonates to control severe hypercalcaemia. Such caution is, in part, driven by concerns about aggravating postoperative hypocalcaemia in a cohort of patients already at heightened risk of developing hungry bone syndrome; a postoperative phenomenon characterised by rapid sequestration of calcium into bone. We review the limited evidence around preoperative bisphosphonate administration in patients with hyperparathyroid crisis and examine the efficacy and safety of intravenous pamidronate in our own patient series. Whilst the management remains largely empirical, we suggest that bisphosphonates can be considered to safely facilitate parathyroidectomy, since intravenous fluid therapy alone is often insufficient to control severe hypercalcaemia. Preoperative calcium optimisation that includes intravenous bisphosphonate therapy should be prioritised over the theoretical risk of aggravating postoperative hypocalcaemia; the latter of which may be ameliorated by adequate preoperative vitamin D replacement.