Calcifediol (2 brand names, 2 dosage forms, 1 route)
Available dosage forms: CAPSULE, EXTENDED RELEASE, CAPSULE.
Routes of administration: ORAL.
Brand Names
- CALDEROL
- RAYALDEE
Indications and Usage
RAYALDEE is a vitamin D3 analog indicated for the treatment of secondary hyperparathyroidism in adult patients with stage 3 or 4 chronic kidney disease and serum total 25-hydroxyvitamin D levels less than 30 ng/mL. Limitations of Use RAYALDEE is not indicated for the treatment of secondary hyperparathyroidism in patients with stage 5 chronic kidney disease or in patients with end-stage renal disease on dialysis.
Contraindications
None.
Adverse Reactions
The following important adverse reactions are discussed in greater detail in other sections of the label: •Hypercalcemia [see Warnings and Precautions (5.1)] •Adynamic Bone Disease [see Warnings and Precautions (5.3)]
Mechanism of Action
Calcifediol (25-hydroxyvitamin D3) is a prohormone of the active form of vitamin D3, calcitriol (1,25‑dihydroxyvitamin D3). Calcifediol is converted to calcitriol by cytochrome P450 27B1 (CYP27B1), also called 1-alpha hydroxylase, primarily in the kidney. Calcitriol binds to the vitamin D receptor in target tissues and activates vitamin D responsive pathways that result in increased intestinal absorption of calcium and phosphorus and reduced parathyroid hormone synthesis.
Overdosage
Excessive administration of RAYALDEE can cause hypercalciuria, hypercalcemia, hyperphosphatemia, or oversuppression of intact PTH. Common symptoms of vitamin D overdosage may include constipation, decreased appetite, dehydration, fatigue, irritability, muscle weakness, or vomiting. Treatment of acute accidental overdosage with RAYALDEE should consist of general supportive measures. If the overdosage is discovered within a short time, induce emesis or perform gastric lavage to prevent further absorption. Obtain serial serum and urine calcium measurements, and assess any electrocardiographic abnormalities due to hypercalcemia. Discontinue supplemental calcium. Treat with standard medical care if persistent and markedly elevated serum calcium levels occur. Calcifediol is not significantly removed by dialysis.