Hyperparathyroidism

Background

  • Causes:
    • Parathyroid adenoma (most common), parathyroid hyperplasia, parathyroid carcinoma
    • Milk alkali syndrome
    • Granulomatous
    • Secondary hyperparathyroidism (response to hypocalcemia)
    • Tertiary hyperparathyroidism due to CKD

Clinical Features

Mnemonic: Stones, Bones, Groans, Moans, Thrones, Psychic Overtones


Differential Diagnosis

Causes of Hypercalcemia

Jaw Spasms

Evaluation

  • Evaluate for underlying etiology/alternate diagnoses of symptoms
  • PTH- elevated
  • Calcium- elevated if primary, low if secondary
  • Phosphate- low in primary, high in secondary
  • Alk phos- elevated

Management

Hypocalcemia

Avoid empiric treatment in patients taking digoxin due to risk for Stone Heart

Hypercalcemia

Asymptomatic or Ca <12 mg/dL

  • Does not require immediate treatment
  • Advise to avoid factors that can aggravate hypercalcemia (thiazide diuretics, Li, volume depletion, prolonged inactivity, high Ca diet)

Mildly symptomatic Ca 12-14 mg/dL

  • May not require immediate therapy; however, an acute rise may cause symptoms necessitating treatment as described for severe hypercalcemia (see below)

Symptomatic or Severe hypercalcemia (Ca >14 mg/dL)

  • Patients are likely dehydrated and require saline hydration as initial therapy
Hydration
  • Isotonic saline at 200-300 mL/hour; adjust to maintain urine output at 100-150 mL/hour
Calcitonin
  • Consider adding calcitonin 4 units/kg SC or IV q12hr in patients w/ Ca >14 mg/dL (3.5 mmol/L) who are also symptomatic (lowers Ca w/in 2-4hr)
  • Tachyphylaxis limits use long term, but is a great choice for emergent cases
Bisphosphonates

Give for severe hypercalcemia due to excessive bone resorption (lowers Ca within 12-48hr)

  • Pamidronate 90mg IV over 24 hours OR
  • Zoledronate 4mg IV over 15 minutes
  • Caution in renal failure, though bisphosphonates have been safely used in pts with pre-existing renal failure[1]
Electrolyte Repletion
Diuresis
  • Furosemide is NOT routinely recommended
  • Only consider in patients with renal insufficiency or heart failure and volume overload
Dialysis

Consider if patient:

  • Anuric with Renal Failure
  • Failing all other therapy
  • Severe hypervolemia not amenable to diuresis
  • Serum Calcium level >18mg/dL
Corticosteroids

Decrease Ca mobilization from bone and are helpful with steroid-sensitive tumors (e.g. lymphoma, MM)

Disposition

See Also

External Links

References

  1. LeGrand SB et al. Narrative Review: Furosemide for Hypercalcemia: An Unproven yet Common Practice. Ann Intern Med. 2008;149:259-263.

Authors:

Claire