mentions CMT: Looking at calcimimetics impact on hypercalcemia of immobilization

[Guest guest]

Hemodial Int. 2006 Jan;10(1):29-34.

Looking at calcimimetics impact on hypercalcemia of immobilization:

Hypotheses and a case study.

Roueff S, s MS, Chuong VT, Abbassi A, Guedon C, Vernejoul MC,

PU.

Service de Nephrologie-Dialyse, Hopital de Saint Maurice, Saint

Maurice, France.

For the treatment of secondary hyperparathyroidism (HPTH-II) in

dialysis patients and hypercalcemia in patients with parathyroid

carcinoma. Calcimimetics are a new class of drugs approved in the

European Community and the United States by the Food and Drug

Administration that were designed to suppress parathyroid hormone

(PTH) levels with a simultaneous reduction in serum calcium and

phosphorus levels, and calcium phosphorus product (Ca x P).

Hypocalcemia is a frequent finding during the correction phase of the

HPTH-II with calcimimetics. By contrast, the appearance of a

hypercalcemia has yet to be described. In this paper, we report a

case of severe hypercalcemia of immobilization in a 40-year-old

hemodialyzed woman treated by cinacalcet HCl for a severe HPTH-II

(PTH>1,000 pg/mL). A kidney transplantation recipient 1983 to 1995,

she was diagnosed with Charcot-Marie Tooth disease in 1991. She had

multiple orthopedic interventions for kidney-related osteoarticular

problems probably favored by the kidney graft and the

immunosuppressive treatment. While she was receiving the maximum dose

of 180 mg/day of cinacalcet HCl and PTH at 443 pg/mL, she needed to

be hospitalized for a right hip prothesis. Two weeks after the

intervention she developed a symptomatic hypercalcemia of 3.57 mmol/L

which was resistant to several measures including lowering the

calcium concentration in the dialysate, withdrawing all vitamin D and

calcium supplementation and the administration of calcitonin. Her

serum calcium level was finally stabilized in the 2.37-2.95 mmol/L by

administration of a single intravenous dose of pamidronate. This

observation illustrates that the pharmacological activation of the

parathyroid CaR and other putative CaR on bone cells by calcimimetics

did not protect against the occurrence of hypercalcemia of

immobilization favored by a severe HPTH-II in a hemodialysis patient.