Calcitriol / Rocalrol / l,25-Vitamin D3



- See:
      - abnormalities associated w/ vit D
      - general discussion of vit D

- Discussion:
    - action of l,25-vitamin D3 is to increase absorption of Ca from intestinal tract;
    - 1,25 Vit D is known mediator of bone resorption thru indirect action on osteoclasts;
    - amount of this metabolite in circulation is regulated by parathyroid hormone;
    - malfunctions involving this metabolite are a major cause of metabolic bone dz;

- Dosage:
    - most potent metabolite of vitamin D available;
    - used for hypocalcemia secondary to chronic renal dialysis, post surgical and idiopathic hypoparathyroidism;
    - dialysis patients:
          - initial dose is 0.25ug/day; may increase dosage by 0.25ug/day at 4-8 week intervals if needed;
          - max dose: 100 mcg qd (available as 20 and 50 mcg);
    - hypoparathyroidism: initial dose is 0.25ug/day given AM;
    - may increase dose at 2-4 week intervals;
    - contraindicated w/: hypercalcemia, evidence of vit D toxicity;
    - must monitor calcium levels frequently;
    - caution w/ digitalis (w/ hypercalcemia) and attempt to maintain good fluid intake;
    - note: when Vit D is measured in units it is in the non hydroxylated form, and when it is measured in micrograms (Rocaltrol) it is in the hydroxylated form (1,25 Vit D)



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Wednesday, August 22, 2012 2:35 pm