A 74-year-old male with a past medical history of severe osteoporosis, chronic obstructive pulmonary disease (COPD), marginal gastric ulcers status-post sleeve gastrectomy, and Crohn’s disease status-post small bowel resection presented to the emergency department due to an acute onset of right shoulder pain. Vital signs revealed a temperature of 37.2°C, blood pressure of 112/61 mmHg, heart rate of 78, respiratory rate of 16 and oxygen saturation of 92% on 1.5 L by nasal cannula, which he used at baseline. Initial laboratory workup revealed severe hypocalcemia at 4.8 mg/dL and hypophosphatemia at 0.8 mg/dL. Upon further history taking, the patient stated that he receives denosumab injections for his severe osteoporosis. The patient denied muscle cramps, spasms, weakness, seizures, facial twitching, lightheadedness, and psychiatric changes. Of note, he had a history of chronic hypocalcemia with a baseline of 7 mg/dL and reported taking daily calcium and vitamin D supplements. His physical examination was unremarkable except for shoulder pain on passive range of motion. Chvostek and Trousseau signs were both negative. Additional laboratory workup (Table ) was significant for hyperparathyroidism and normal levels of magnesium, albumin, and vitamin D. His arterial blood gas results (Table ) revealed respiratory acidosis presumed to be due to COPD.\nThe patient was admitted to the intensive care unit, monitored on cardiac telemetry, and started on IV calcium carbonate in addition to his home calcium and vitamin D oral supplements. Endocrinology was consulted and calcium levels were trended until normalization. The patient was ultimately discharged on calcium carbonate 1,250 mg by mouth three times per day, calcium-vitamin D gummies by mouth three times per day, cholecalciferol 1,000 international units by mouth two times per day, and calcitriol 0.5 mcg oral capsule four times per day. His serum calcium level at eight months post-discharge has been maintained at roughly 9.5 mg/dL on this regimen and he has remained asymptomatic throughout.
A 55-year-old Caucasian woman on peritoneal dialysis for the last three years due to lupus nephritis was seen in the dialysis clinic for a routine follow-up. Her medical problems included hypertension, secondary hyperparathyroidism, and documented osteoporosis on DEXA scan (Dual energy X-ray absorptiometry) with left femoral neck BMD at 0.637 g/cm2; 2.9 standard deviation below peak BMD. Her medications included Amlodipine 5mg, Cinacalcet 60 mg, and Epoetin weekly injections.\nShe complained of fatigue, muscle cramps, and paresthesias of the hands and feet for the past week. Vital signs were stable. Physical exam was unremarkable with negative Chvostek's and Trousseau's signs. Laboratory work-up showed profound hypocalcemia with a total calcium level of 6.4 mg/dL with corrected calcium level of 6.9mg/dL (serum albumin level of 3.4 g/dL) and markedly increased serum intact PTH level (iPTH) of 2601 pg/mL (). Serum phosphate and serum alkaline phosphatase level was within normal reference range at 3.1 mg/dl and 84 U/L, respectively. Upon history taking, she was found to have received a new medication, denosumab 60mg subcutaneously, prescribed by her rheumatologist 10 days prior to the current presentation.\nBefore the administration of denosumab, the patient had normal serum values of calcium (9.5 mg/dL), phosphorus (3.8 mg/dL), alkaline phosphatases (96 U/L), and 25 vitamin D with slightly elevated iPTH level at 442 pg/mL. The patient was supplemented with 3,000 mg/dL of oral calcium along with oral Calcitriol 0.5mcg daily and Cinacalcet was held. The peritoneal dialysis solution was also changed from low calcium to regular calcium. All these measures resolved her symptoms with serum calcium normalizing (corrected calcium, 8.7 mg/dL) 5 days later whereas iPTH took almost 4 weeks to come back to baseline level (). Subsequently, she was managed as an out-patient with close monitoring of calcium homeostasis.