Mild hypercalcemia

Several patients have exhibited a clinical picture resembling FHH, but no CaR mutations could be identified. These individuals also exhibited various forms of autoimmunity (e.g., antithyroid antibodies) and harbored anti-CaR antibodies that reduced the high CaQ+ -evoked stimulation of MAPK and PLC in cells transfected with the wild type receptor. Thus both antireceptor antibodies and mutations in the CaR can render the receptor resistant to activation by Caq+, producing a clinical picture of mild, PTH-dependent hypocalciuric hypercalcemia [3]. 

Hypercalcemia is defined as a calcium concentration greater than 10.2 mg/dL (2.55 mmol/L). It maybe categorized as mild if total serum calcium is 10.3 to 12 mg/dL (2.575 to 3 mmol/L), moderate if total serum calcium is 12.1 to 13 mg/dL... 

Because the severity of symptoms and the absolute serum concentration are poorly correlated in some patients, institution of therapy should be dictated by the clinical scenario. All patients with hypercalcemia should be treated with aggressive rehydration normal saline at 200 to 300 mL/hour is a routine initial fluid prescription. For patients with mild hypocalcemia, hydration alone may provide adequate therapy. The moderate and severe forms of hypercalcemia are more likely to have significant manifestations and require prompt initiation of additional therapy. These patients may present with anorexia, confusion, and/or cardiac manifestations (bradycardia and arrhythmias with ECG changes). Total calcium concentrations greater than 13 mg/dL (3.25 mmol/L) are particularly worrisome, as these levels can unexpectedly precipitate acute renal failure, ventricular arrhythmias, and sudden death. 

Therapeutic options for the treatment of hypercalcemia should be directed toward the level of corrected serum calcium and the presence of symptoms. Adequate treatment of mild or asymptomatic hypercalcemia may be achieved on an outpatient basis with nonpharmacologic measures. Moderate to severe or symptomatic hypercalcemia almost always requires pharmacologic intervention. 

Therapeutic options for the treatment of hypercalcemia should be directed toward the level of corrected serum calcium and the presence of symptoms (Fig. 96-5). Hypercalcemia may be classified as mild [corrected calcium equal to 10.5-11.9 g/dL (2.6-3 mmol/L)], moderate [12-13.9 g/dL (3-3.5 mmol/L)], and severe [greater than 14 g/dL (3.5 mmol/L)].26 Adequate treatment of mild or asymptomatic hypercalcemia may be achieved on an outpatient basis with nonpharmacologic measures. Moderate to severe or symptomatic hypercalcemia almost always requires pharmacologic intervention. 

Calciuric therapy in the form of hydration is a key component of the treatment of hypercalcemia, regardless of severity or presence of symptoms.28 Mild or asymptomatic patients may be encouraged to increase oral fluid intake (3-4 L/day). Patients with moderate to severe or symptomatic hypercalcemia should receive normal saline at 200 to 500 mL/hour according to dehydration and cardiovascular status. Patients should be encouraged to ambulate as much as possible because immobility enhances... 

Assess the patient s symptoms to determine the need for laboratory studies. Determine if absence of symptoms in the presence of mild hypercalcemia warrants conservative outpatient management. 

Clinical presentation depends on the degree of hypercalcemia and rate of onset. Mild to moderate hypercalcemia (less than 13 mg/dL) can be asymptomatic. 

Management of patients with asymptomatic, mild to moderate hypercalcemia begins with attention to the underlying condition and correction of fluid and electrolyte abnormalities. 

Hypercalcemia Hypercalcemia may occur when large doses of calcium are administered to patients with chronic renal failure. Mild hypercalcemia may exhibit as nausea, vomiting, anorexia, or constipation, with mental changes such as stupor, delirium, coma, or confusion. 

Ora/ - May cause constipation and headache. Mild hypercalcemia (Ca" " greater than 10.5 mg/dL) may be asymptomatic or manifest itself as Anorexia, nausea, and vomiting. More severe hypercalcemia (Ca 12 mg/dL) is associated with confusion. 

Tamoxifen administration is associated with few toxic side effects, most frequently hot flashes (in 10-20% of patients) and occasionally vaginal dryness or discharge. Mild nausea, exacerbation of bone pain, and hypercalcemia may occur. 

This rather common disease, if associated with symptoms and significant hypercalcemia, is best treated surgically. Oral phosphate and bisphosphonates have been tried but cannot be recommended. Asymptomatic patients with mild disease often do not get worse and may be left untreated. The calcimimetic agent cinacalcet, discussed previously, has been approved for secondary hyperparathyroidism and is in clinical trials for the treatment of primary hyperparathyroidism. If such drugs prove efficacious, medical management of this disease will need to be reconsidered. 

Reviews of parathyroid hormone have suggested that it is generally well tolerated (4,5,6). The adverse effects of parathyroid hormone that have been reported in clinical trials are mild and include transient bone pain, nausea, dizziness and local irritation at the injection site (7). Hypercalcemia, which is common, is usually mild and asymptomatic. Adverse effects, including hypercalcemia, appear to be dose related in the therapeutic range. 

Mild asymptomatic hypercalcemia is common during treatment with parathyroid hormone (15). The hypercalcemia is persistent, and requires dosage reduction in 3% of patients using 20 micrograms/day and in 11% using 40 micrograms/day (16). Transient mild hypercalciuria and increased serum phosphate are common but do not usually limit therapy. 

Hypercalcemia, usually mild and not requiring specific treatment, was reported in 43 of 100 patients receiving high-dose somatropin in intensive care (SEDA-13,1308 65). 

Broadly speaking, idiopathic hypercalcemia has been divided into two types, the so-called mild type typified by the cases described by Lightwood in 1952 and the so-called severe type typified by the cases de-... 

Calcium edetate can cause mild transient hypercalcemia (4) and hypercalciuria (5). 

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