Calcitriol Dosage

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Usual Adult Dose for:

Usual Pediatric Dose for:

Additional dosage information:

Usual Adult Dose for Hypocalcemia

Oral
Initial dose: 0.25 mcg orally once a day.
Maintenance dose: May increase by 0.25 mcg/dose at 4 to 8 week intervals.

Parenteral
Initial dose: 0.5 mcg IV 3 times a week.
Maintenance dose: May increase by 0.25 to 0.5 mcg/dose at 2 to 4 week intervals.

Usual Adult Dose for Renal Osteodystrophy

Oral
Initial dose: 0.25 mcg orally once a day.
Maintenance dose: May increase by 0.25 mcg/dose at 4 to 8 week intervals.

Parenteral
Initial dose: 0.5 mcg IV 3 times a week.
Maintenance dose: May increase by 0.25 to 0.5 mcg/dose at 2 to 4 week intervals.

Usual Adult Dose for Hypoparathyroidism

Initial dose: 0.25 mcg orally once a day in the morning.
Maintenance dose: May increase by 0.25 mcg/dose at 2 to 4 week intervals. Most patients respond to 0.25 to 2 mcg once a day.

Usual Adult Dose for Rickets

1 mcg orally once a day

Usual Adult Dose for Secondary Hyperparathyroidism

Predialysis patients: 0.25 mcg orally once a day in the morning.

Dialysis patients: 0.25 mcg orally once a day in the morning. Increase dose, if needed, by 0.25 mcg/dose at 2 to 4 week intervals. For some patients 0.25 mcg orally every other day may be enough. Most patients respond to doses of 0.25 to 1 mcg once a day. Alternatively, 0.5 to 4 mcg IV may be administered three times per week at the end of each dialysis.

Pulse oral therapy:
Study (n=5), patients on Continuous Ambulatory Peritoneal Dialysis:
5 mcg orally given twice per week.
Study (n=19), patients on hemodialysis:
4 mcg orally given twice per week.

Usual Pediatric Dose for Hypoparathyroidism

Less than 1 year: 0.04 to 0.08 mcg/kg orally once a day.

1 to 5 years: 0.25 to 0.75 mcg orally once daily. May increase by 0.25 mcg/dose at 2 to 4 week intervals.

Greater than or equal to 6 years: 0.5 to 2 mcg. May increase by 0.25 mcg/dose at 2 to 4 week intervals.

Usual Pediatric Dose for Rickets

Vitamin D dependent rickets: 1 mcg orally once a day.

Vitamin D resistant rickets (familial hypophosphatemia): Initial: 0.015 to 0.02 mcg/kg orally once daily; maintenance: 0.03 to 0.06 mcg/kg orally once daily; maximum dose: 2 mcg once daily.

Usual Pediatric Dose for Hypocalcemia

Hypocalcemia secondary to hypoparathyroidism:
Neonates: 1 mcg orally once daily for the first 5 days of life, or 0.02 to 0.06 mcg/kg/day.

Hypocalcemic tetany:
Neonates: 0.05 mcg/kg IV once daily for 5 to 12 days or 0.25 mcg orally once daily followed by 0.01 to 0.10 mcg/kg/day divided in 2 doses daily
(maximum daily dose: 2 mcg).

Management of hypocalcemia in patients with chronic kidney disease (CKD): Indicated for therapy when serum levels of 25(OH)D are greater than 30 ng/mL (75 nmol/L) and serum levels of intact parathyroid hormone (iPTH) are above the target range for the stage of CKD; serum levels of corrected total calcium are less than 9.5 to 10 mg/dL and serum levels of phosphorus are less than age appropriate upper limits of normal (ULN).

Children and Adolescents: CKD Stages 2 to 4:

Less than 10 kg: 0.05 mcg orally every other day.
10 to 20 kg: 0.1 to 0.15 mcg orally daily.
Greater than 20 kg: 0.25 mcg orally daily.

If iPTH decrease is less than 30% after 3 months of therapy and serum levels of calcium and phosphorus are within the target ranges based upon the CKD Stage, increase dosage by 50%.

If iPTH decrease is less than the target range for CKD stage, hold calcitriol therapy until iPTH increases to above target range; resume therapy at half the previous dosage (if dosage is less than 0.25 mcg capsule or 0.05 mcg liquid, use every other day therapy).

If serum levels of total corrected calcium exceed 10.2 mg/dL, hold calcitriol therapy until serum calcium decreases to less than 9.8 mg/dL; resume therapy at half the previous dosage (if dosage is less than 0.25 mcg capsule or 0.05 mcg liquid, use every other day therapy).

If serum levels of phosphorus increase to greater than the age appropriate upper limits, hold calcitriol therapy (initiate or increase phosphate binders until the levels of serum phosphorus decrease to age appropriate limits); resume therapy at half the previous dosage.

Children and Adolescents with CKD Stage 5: Serum calcium times phosphorus product (Ca x P) should not exceed 65 mg(2)/dL(2) for infants and children less than 12 years of age and 55 mg(2)/dL(2) for adolescents, serum phosphorus should be within target, serum calcium less than 10 mg/dL.

iPTH 300 to 500 pg/mL: 0.0075 mcg/kg orally or IV per dialysis session (3 times/week); not to exceed 0.25 mcg daily.

iPTH greater than 500 to 1000 pg/mL: 0.015 mcg/kg orally or IV per dialysis session (3 times/week); not to exceed 0.5 mcg daily.

iPTH greater than 1000 pg/mL: 0.025 mcg/kg orally or IV per dialysis session (3 times/week); not to exceed 1 mcg daily.

Dosage adjustment: If iPTH decrease is less than 30% after 3 months of therapy and serum levels of calcium and phosphorus are within the target ranges based upon the CKD Stage 5, increase dosage by 50%.

Renal Dose Adjustments

No adjustments recommended, however, patients with renal insufficiency are more prone to the development of hypercalcemia and should be closely monitored.

Liver Dose Adjustments

Data not available

Dose Adjustments

Some patients may respond to as little as 0.25 mcg every other day. Most patients respond to 0.5 to 1 mcg orally once a day or 0.5 to 3 mcg IV 3 times a week.

Precautions

Calcitriol should be withheld if hypercalcemia develops.

Dialysis

Vitamin D and its metabolites are not dialyzable.

Other Comments

Serum calcium should be monitored once to twice a week during dose titration, and approximately once a month after stabilization of the dosage.

The U.S. RDA for calcium in adults is 800 to 1200 mg.

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