Efficacy and Safety of Intravenous Pamidronate for Parathyroid Hormone-dependent Hypercalcemia in Hospitalized Patients.

CONTEXT: Bisphosphonates are effective for hypercalcemia of malignancy (HOM). Efficacy and safety data for bisphosphonates in parathyroid hormone-related hypercalcemia (PTHRH) are rare, including pamidronate (Pam), which is not indicated for this condition. OBJECTIVE: This work aims to evaluate the efficacy and safety of Pam for moderate-to-severe PTHRH. METHODS: This retrospective case-control study was conducted at a tertiary care medical center. Patients included adults hospitalized with serum calcium levels greater than 12 mg/dL, from October 29, 2013 to December 17, 2019. Etiology was categorized as PTHRH or PTH-independent. Clinical and laboratory data of PTHRH patients treated with Pam (PTHRH-Pam+) were compared to Pam-untreated counterparts (PTHRH-Pam-). RESULTS: Thirty-four patients with 37 hospitalizations for PTHRH (Pam-treated and -untreated) met the inclusion criteria. Pam was given in 24 of 37 cases (64.8%). Admission serum calcium levels for the PTHRH-Pam+ group were higher than for PTHRH-Pam- group (14.4 mg/dL vs 13.0 mg/dL, P = .005). Median total Pam dose was 60 mg (range, 30-180 mg) in the treated group. Serum calcium decreased 3.5 mg/dL for PTHRH-Pam+ vs 1.6 mg/dL for PTHRH-Pam- (P = .003). No PTHRH-Pam+ patients developed hypocalcemia or acute kidney injury. Nadir serum phosphorus levels were lower in the PTHRH-Pam+ vs PTHRH-Pam- group (1.7 mg/dL vs 2.4 mg/dL, respectively, P = .004). Three PTHRH-Pam+ patients developed severe hypophosphatemia; all resolved with intravenous and oral supplementation. Seventeen patients underwent parathyroidectomy, of whom 10 received Pam within 28 days preoperatively. Postoperatively, 4 developed hypocalcemia and 3 hypophosphatemia. CONCLUSION: This study demonstrates that Pam is effective and safe for treating PTHRH, while ensuring close laboratory monitoring of calcium and phosphorus metabolism. Larger, prospective studies are needed to establish the role of Pam and other potent bisphosphonates in moderate-to-severe PTHRH.

Hyperprolactinemia diagnosis in elderly men: a cohort of 28 patients over 65 years.

PURPOSE: To characterize a cohort of elderly men with prolactinomas and their response to treatment. METHODS: We have identified 28 elderly men diagnosed after the age of 65 with prolactinomas at seven different endocrine clinics in Israel. A retrospective electronic chart review identified a control group of 76 younger men with macroprolactinomas treated in one of the centers. RESULTS: Mean age at diagnosis was 71.3 ± 5.6 (range 65-86) years, and current age 76.6 ± 7.5 years. Initial complaints leading to diagnosis included sexual dysfunction in 17 males (61%), headaches in two patients (7%), and visual abnormalities in two (7%). Three men presented with osteoporosis. Ten patients (36%) were diagnosed incidentally following brain imaging for unrelated reasons. Seventeen patients (61%) had macroadenoma, while eleven (39%) presented with a microadenoma or no visible adenoma. Mean prolactin (PRL) at presentation was 1594 (median 382; range 50-18,329) ng/ml. Testosterone was low in 21 men. Patients were treated with cabergoline (max dose, 1.1 ± 0.5 mg/week), except for one given bromocriptine; none required pituitary surgery or radiotherapy. Treatment normalized PRL in 24 patients, and in three men PRL suppressed to <2 ULN. Fifteen men normalized testosterone, three improved without normalization, and in three the normal baseline level increased. After a mean follow-up of 5.3 years, 14/15 patients harboring a macroadenoma showed significant adenoma shrinkage. Most patients reported improvement of low libido/erectile dysfunction. In the control group 60 men (79%) achieved PRL normalization. CONCLUSIONS: Elderly men with prolactinomas are diagnosed incidentally in 36% of cases. Long-term medical therapy is successful, achieving biochemical remission, adenoma shrinkage, and clinical improvement in almost all patients.