Advantages of adjusting the initial dose of intravenous calcitriol according to PTH levels.
BACKGROUND
To assess the usefulness of starting calcitriol therapy with a dose proportional to the degree of hyperparathyroidism, 141 patients from 28 centers were treated with intravenous calcitriol for 6 months. The aim was to achieve a final PTH between 125 and 250 pg/mL. Patients with serum PTH>250 pg/mL were included in the study and divided into 4 groups according to baseline PTH levels.


METHODS
The study was completed by 100 patients, a third of which were treated strictly according to the protocol, labeled "compliants"; thus, calcitriol was started according to baseline PTH levels. Two thirds of patients, labeled "noncompliants," showed one or more violation in the dosage regimen.


RESULTS
After 2 months of treatment with calcitriol, 59% of the "compliants" and 35% of the "noncompliants" decreased their PTH levels>40% (P = 0.022), 70%, and 49%, respectively after 3 months of treatment. After 3 months of treatment, 67% of the "compliants" reached the target (PTH 125 to 250 pg/mL) in contrast with 23% of the "noncompliants" (P < 0.001). The number of hypercalcemic and hyperphosphatemic episodes was significantly lower in the "compliants" group (P < 0.006).


CONCLUSIONS
These results demonstrate several advantages when calcitriol therapy is started with a dose proportional to the severity of hyperparathyroidism.
Rodríguez-García
Minerva
M
Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación, Hospital Central de Asturias, Oviedo, España.
Fernández-Martín
José Luis
JL
de Castañeda
Jaime Ruiz
JR
Hervás-Sánchez
José
J
Cannata-Andía
Jorge Benito
JB
D000368:Aged; D002117:Calcitriol / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D002120:Calcium Channel Agonists / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000188:drug therapy; D007275:Injections, Intravenous; D007676:Kidney Failure, Chronic / Q000097:blood / Q000150:complications; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D010349:Patient Compliance; D006435:Renal Dialysis / Q000009:adverse effects
D002120:Calcium Channel Agonists; D010281:Parathyroid Hormone; D002117:Calcitriol