Alfacalcidol 💊
📖 About
Always check the BNF link here before prescribing.
- 💊 1-alpha hydroxycholecalciferol, a synthetic analogue of Vitamin D.
- ✅ Effective even in patients with renal disease (does not require renal hydroxylation at C-1 position).
⚡ Mechanism of Action
- 🔄 Alfacalcidol is rapidly converted in the liver to 1,25-dihydroxy Vitamin D (calcitriol).
- 🦴 Active metabolite enhances intestinal calcium absorption and promotes bone mineralisation.
- 🧬 Also modulates PTH secretion, useful in secondary hyperparathyroidism of CKD.
🩺 Indications & Dosing
- Vitamin D deficiency, particularly with renal impairment.
- Renal osteodystrophy & secondary hyperparathyroidism in CKD.
- ⚠️ Use lower doses in elderly due to higher hypercalcaemia risk.
- Typical starting dose: Alfacalcidol 1 micrograms OD, maintenance usually 0.25–1 micrograms/day.
💊 Dose Range (verify in BNF/datasheet)
| Name |
Details |
| Alfacalcidol |
Starting dose: 0.25–1 microgram OD
Route: PO
|
⚠️ Interactions
- ⬇️ Efficacy reduced by enzyme inducers such as phenytoin and barbiturates.
- 🧂 Concomitant calcium or phosphate supplements ↑ risk of hypercalcaemia/hyperphosphataemia.
⚠️ Cautions
- ⚡ Risk of hypercalcaemia (monitor U&E + calcium regularly).
- 🦴 May cause metastatic calcification or renal stones if calcium uncontrolled.
- 👴 Use with care in elderly or immobilised patients (higher hypercalcaemia risk).
🚫 Contraindications
- See BNF for full list – avoid if persistent hypercalcaemia present.
💥 Side Effects
- ⬆️ Hypercalcaemia and nephrocalcinosis.
- 🌡️ Rash, urticaria, pruritus (rare).
- 🩺 Symptoms of toxicity: nausea, vomiting, weakness, arrhythmias (due to hypercalcaemia).
📑 References
