Persistent hypercalcemia after parathyroidectomy in an adolescent and effect of treatment with cinacalcet HCl.
BACKGROUND
Hyperparathyroidism is uncommon in adolescence and is more likely to persist after parathyroidectomy than in adults. Cinacalcet HCl is a new calcimimetic that has been used successfully for the treatment of primary and secondary hyperparathyroidism in adults, but its use in adolescents has not been reported.


METHODS
A 16 year-old male presented with hypercalcemia that had persisted for 1.5 years after parathyroidectomy for primary hyperparathyroidism. Parathyroid hormone (PTH) concentrations were nonsupressed despite a mean (SD) serum calcium concentration of 2.82 (0.06) mmol/L. Treatment with cinacalcet HCl was initiated and a pharmacodynamic profile was obtained for serum calcium, phosphorus, and PTH. Cinacalcet HCl normalized serum calcium. The changes in PTH were assay dependent.


OBJECTIVE
We use this case conference to review the evaluation of hypercalcemia in adolescents, examine the changes in relevant laboratory results during treatment with cinacalcet HCl, and discuss differences among assays for PTH.


CONCLUSIONS
Interpretation of PTH results in patients treated with cinacalcet HCl requires consideration of the pharmacodynamic effects of the drug and the nature of the PTH assay.
Henrich
Lorin M
LM
Department of Pathology, University of Virginia Medical School, Charlottesville, VA 22908, USA. lmh5p@virginia.edu
Rogol
Alan D
AD
D'Amour
Pierre
P
Levine
Michael A
MA
Hanks
John B
JB
Bruns
David E
DE
D000293:Adolescent; D002118:Calcium / Q000097:blood; D000069449:Cinacalcet; D003937:Diagnosis, Differential; D006801:Humans; D006934:Hypercalcemia / Q000188:drug therapy* / Q000209:etiology; D049950:Hyperparathyroidism, Primary / Q000601:surgery*; D008297:Male; D009281:Naphthalenes / Q000627:therapeutic use*; D010281:Parathyroid Hormone / Q000097:blood; D016105:Parathyroidectomy / Q000009:adverse effects; D010758:Phosphorus / Q000097:blood
D009281:Naphthalenes; D010281:Parathyroid Hormone; D010758:Phosphorus; D002118:Calcium; D000069449:Cinacalcet