Products
Calcifediol was approved in the United States in 2016 and in many countries in 2020 in extended-release capsule form (Rayaldee).
Structure and properties
Calcifediol (C27H44O2, Mr = 400.6 g/mol) is a hydroxylated derivative of vitamin D3 (cholecalciferol). It is 25-hydroxycholecalciferol or 25-hydroxyvitamin D3. Calcifediol is present in the drug as calcifediol monohydrate, a white crystalline powder that is practically insoluble in water.
Effects
Calcifediol is a prohormone of calcitriol. It is metabolized primarily in the kidney by CYP27B1 to calcitriol. Among other effects, calcitriol increases the absorption of calcium and phosphate in the intestine and reduces the synthesis of parathyroid hormone. This lowers the PTH concentration in the blood. The half-life is about 11 days in healthy individuals and increases to 25 days in renal insufficiency.
Indications
For the treatment of secondary hyperparathyroidism in adults with chronic renal insufficiency.
Dosage
According to the SmPC.
Contraindications
- Hypersensitivity
For complete precautions, see the drug label.
Interactions
Drug-drug interactions have been described with CYP3A4 inhibitors, thiazides, cholestyramine, and antiepileptic drugs such as phenobarbital.
Adverse effects
The most common possible effects include:
- Anemia
- Nasopharyngitis
- Increased creatinine levels in the blood
- Difficulty breathing, cough
- Heart failure
- Constipation
