Dosing and uses of Calcijex, Rocaltrol (calcitriol)
Adult dosage forms and strengths
capsule
- 0.25mcg
- 0.5mcg
oral solution
- 1mcg/mL
injectable solution
- 1mcg/mL
Chronic Renal Dialysis Associated Hypocalcemia
OraL
- Initial: 0.25 mcg PO qDay to every other day; titrate by 0.5-1 mcg/day q4-8Weeks
IV
- Initial: 1-2 mcg IV (0.02 mcg/kg) 3 times/week; adjust dose every 2-4 weeks
- Maintenance: 0.5-4 mcg IV 3 times/week
Hypoparathyroidism/Pseudohypoparathyroidism
Initial: 0.25 mcg PO qDay; titrate by 0.25 mcg q2-4Weeks
Maintenance: 0.5-2 mcg PO qDay
Secondary Hyperparathyroidism in Moderate to Severe Kidney Disease
0.25 mcg/day PO; may increase to 0.5 mcg/day
Vitamin D Dependent Rickets (Off-label)
1 mcg PO qDay
Administration
Goal is to maintain serum Ca 9-10 mg/dL
Pediatric dosage forms and strengths
Doing Forms & Strengths
capsule
- 0.25mcg
- 0.5mcg
oral solution
- 1mcg/mL
injectable solution
- 1mcg/mL
Chronic Renal Dialysis Associated Hypocalcemia
0.25-2 mcg/day PO qDay
Hypoparathyroidism/Pseudohypoparathyroidism
<1 year: 0.04-0.08 mcg/kg PO qDay
1-5 years: 0.25-0.75 mcg PO qDay
>6 years: 0.5-2 mcg PO qDay
Familial Hypophosphatemia
Initial: 0.015-0.02 mcg/kg PO qDay
Maintenance: 0.03-0.06 mcg/kg PO qDay
No more than 2 mcg PO qDay
Secondary Hyperparathyroidism in Moderate to Severe Kidney Disease
<3 years: 0.01-0.015 mcg/kg/day
≥3 years: 0.25 mcg/day PO; may increase to 0.5 mcg/day
Hypocalcemia in Premature Infants
1 mcg qDay PO for 5 days
Vitamin D-Dependent Rickets (Off-label)
0.5 mg PO twice daily; adjust dose to maintain normal serum calcium and PTH levels; after 2 years, median dose is 0.25 mcg/day
Hypocalcemic Tetany in Premature Infants (Off-label)
0.05 mcg/kg IV qDay for 5-12 days
Calcijex, Rocaltrol (calcitriol) adverse (side) effects
Frequency not defined
Abdominal pain
Apathy
BUN and creatinine increased
Cardiac arrhythmia
Constipation
Dry mouth
Dehydration
Growth suppression
Headache
Hyperthermia
Hypercalcemia
Hypercholesteremia
Hypermagnesemia
Hyperphosphatemia
Hypertension
Libido decreased
Metallic taste
Muscle or bone pain
N/V
Nocturia
Pruritus
Psychosis
Somnolence
Weakness
Warnings
Contraindications
Hypercalcemia or evidence of vitamin D toxicity
Hypersensitivity to calcitriol, other vitamin D analogues, or other ingredients
Cautions
Excessive vitamin D may suppress parathyroid hormone
Risk of hyperphosphatemia, hypercalciuria
Efficacy may be unpredictable in patients with malabsorption syndrome
Adequate dietary calcium supplementation necessary for clinical response to vitamin d
Use caution in malabsorption syndrome, renal/hepatic impairment,
Pregnancy and lactation
Pregnancy category: C
Lactation: Enters breast milk; not recommended
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Calcijex, Rocaltrol (calcitriol)
Mechanism of action
Calcitriol is a potent metabolite to the active form of vitamin D, which in turn controls the reabsorption of calcium by the kidneys, controls the intestinal absorption of dietary calcium; decreases excessive serum phosphate levels, bone resorption, and parathyroid hormone levels
Absorption
Onset of action: 2-6 hr (PO)
Peak plasma time: 3-6 hr
Duration: 3-5 days (PO/IV)
Distribution
Protein bound: 99.9%
Metabolism
24-hydroxylase to calcitroic acid; also by stepwise hydroxylation to vitamin D3 lactone ring
Elimination
Half-life elimination: 5-8 hr (adults); 27 hr (children)
Excretion: Feces (50%); urine (16%)
Administration
IV Administration
Rapid injection through catheter at end of hemodialysis
Usually single daily dose
