What is calcitriol, and how does it work (mechanism of action)?
Calcitriol is a synthetic (man-made) active form of vitamin D3 (cholecalciferol). It is used to treat and prevent low levels of calcium in the blood of patients who have kidney disease or problems with their parathyroid gland, the gland that controls the amount of calcium in blood through its secretion of parathyroid hormone.
Calcium plays an important role in maintaining bone health, and low levels of calcium may cause bone disease. Calcitriol increases blood levels of calcium by increasing the absorption of calcium in the kidneys, increasing the absorption of calcium and phosphorus from the intestine, and increasing the release of calcium and phosphorus from the bones. Calcitriol helps the body to use calcium found in foods and supplements.
What brand names are available for calcitriol?
Is calcitriol available as a generic drug?
Do I need a prescription for calcitriol?
What are the side effects of calcitriol?
Excessive vitamin D may lead to hypercalcemia (abnormally high levels of calcium in the blood), hypercalciuria (elevated levels of calcium in the urine), hyperphosphatemia (high levels of phosphate in the blood), and bone disease. To avoid complications, vitamin D and its derivatives should be avoided during calcitriol therapy.
Hypercalcemia has been reported in patients treated with calcitriol. Patients should avoid making any sudden changes in their dietary calcium intake and maintain adequate intake of fluid (hydration) during treatment.
Which drugs or supplements interact with calcitriol?
Calcitriol should not be used with other vitamin D products because of the increased risk of additive side effects and toxicity.
Cholestyramine (Questran), colestipol (Colestid), mineral oil, and orlistat (Alli, Xenical) may decrease the intestinal absorption of calcitriol. Separating the administration of these medications and calcitriol may prevent this interaction.
Phenytoin (Dilantin) and phenobarbital (Luminal) may reduce blood concentrations of calcitriol, decreasing treatment effectiveness. Higher doses of calcitriol may be necessary if these drugs are used together with calcitriol.
Thiazide diuretics may increase the blood levels of calcium. Since calcitriol also increases calcium levels, taking these two types of medications together may cause hypercalcemia (abnormally highly levels of calcium).
Magnesium containing medications (for example, antacids) should be avoided in patients undergoing chronic renal dialysis who are taking calcitriol. These patients are at high risk of experiencing hypermagnesemia (high blood levels of magnesium) as their kidneys are unable to remove adequate amounts of magnesium from the blood.
What is the dosage for calcitriol?
- The recommended initial oral dose for treating low calcium due to kidney dialysis is 0.25 mcg daily.
- The dose may be increased by 0.25 mcg daily every 4 to 8 weeks.
- Most patients respond to 0.5 to 1 mcg daily.
- The oral dose for treating hypoparathyroidism is 0.25 mcg to 2 mcg daily.
Is calcitriol safe to take if I'm pregnant or breastfeeding?
There are no adequate and well-controlled studies of calcitriol treatment in pregnant women. Calcitriol should be used during pregnancy only if the potential benefit justifies the potential risk to the unborn baby.
Calcitriol may be excreted in human milk. Mothers should not breastfeed while taking calcitriol.
What else should I know about calcitriol?
What preparations of calcitriol are available?
- Oral liquid filled capsules: 0.25 and 0.5 mcg
- Oral solution: 1 mcg/ml
- Solution for injection: 1 and 2 mcg/ml
How should I keep calcitriol stored?
Calcitriol should be stored at room temperature, between 15 C and 30 C (59 F and 86 F). Protect from light.
Calcitriol (Rocaltrol, Calcijex is a discontinued brand) is a medication prescribed to treat low levels of calcium in people with kidney disease, rickets, and familial hypophosphatemia. Side effects, drug interactions, dosing, storage, and pregnancy and breastfeeding information should be reviewed prior to taking any medication.
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Rickets is caused by a deficiency of vitamin D, calcium, or phosphate. Infants and children who are exclusively breastfed, have dark skin, and infants born to mothers who are vitamin D deficient are most at risk for developing rickets. Symptoms and signs of rickets include bone pain, delayed teeth formation, short stature, skeletal deformities (bowlegs, abnormally shaped skull), and decreased muscle strength. Treatment of rickets depends upon the cause, but the first step usually involves correcting any abnormal levels of calcium, phosphate, or vitamin D with supplements.
Is Psoriasis Contagious?
Psoriasis is an incurable skin disease that causes reddish patches of skin topped with a thick layer of dry silvery scales. Psoriasis cannot spread and is not contagious.
Treatment & Diagnosis
Medications & Supplements
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You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
FDA Prescribing Information