Changes in treatment needs for chronic postoperative hypoparathyroidism during initiation of conventional treatment compared to stable phase of treatment

In our clinical experience, need for doses of active vitamin D and calcium supplements changes during the period following a diagnosis of postsurgical hypoparathyroidism (HypoPT), but only sparse data are available. In the present study, we aimed to investigate the magnitude of changes in need for activated vitamin D (alfacalcidol) and calcium supplements during initiation of therapy as well as time to be expected until a stable phase was achieved. Furthermore, we determined the frequency of (unexpected) episodes of hypo‐ and hypercalcaemia after reaching a steady state for alfacalcidol and calcium. Methods Retrospective study of twenty‐four patients with chronic postsurgical HypoPT (>6 months) diagnosed from 2016 to 2018. Data were extracted from medical records on doses of alfacalcidol and calcium as well as ionized plasma calcium levels (P‐Ca 2+ ) from time of diagnosis and until 86 weeks after surgery. Results Patients were treated with alfacalcidol and calcium in order to maintain a stable concentration of P‐Ca 2+ . Our data demonstrated a great variation in treatment needs until 11 weeks after surgery, where the mean doses of alfacalcidol stabilize, while calcium doses stabilized a bit earlier. After the stable phase had emerged, 21 out of 24 patients continued to have one or more episodes of spontaneous hypo‐ or hypercalcaemia. Conclusions Patients with chronic HypoPT attain a steady state for alfacalcidol 11 weeks after the diagnosis. Continuous monitoring of P‐Ca 2+ is of continued importance after reaching steady state due to a high frequency of spontaneous hypo‐ or hypercalcaemia.