Drug reference

Alfacalcidol

Vitamin · Bone metabolism regulator

Also known as 1 α-OHD₃

VitaminBone metabolism regulator

CDSCO approvedSchedule H

EXCRETION

—

not curated

INTERACTIONS

—

none in our sources

PREGNANCY

—

not curated

Mechanism

Alfacalcidol is a prodrug that is rapidly hydroxylated in the liver to 1,25 (OH)₂D₃ or calcitriol. Calcitriol increases the synthesis of calcium channels and a carrier protein for Ca2+ (calcium binding protein or Calbindin) to promote intestinal absorption of calcium and phosphate. It binds to a cytoplasmic vitamin D receptor (VDR), translocates to the nucleus, and increases synthesis of specific mRNA to regulate protein synthesis.

Indications

Renal bone diseaseVitamin D dependent ricketsVitamin D resistant ricketsHypoparathyroidismOsteoporosisShort bowel syndrome (nutritional deficiencies)secondary hyperparathyroidism in patients with chronic kidney disease (CKD)

Dosing

Adult: 1–2 µg/day orally
Pediatric: Children < 20 kg: 0.5 µg/day orally
Hepatic adjustment: No adjustment needed; metabolic activation in liver does not pose a problem even in severe liver disease.