Section :
Alfacalcidol
COMPOSITION :
Each soft gelatin capsule contains : Alfacalcidol 0.25 mcg or 1mcg .
DESCRIPTION :
Alfacalcidol (1α- hydroxyvitamin D3 ) is a vitamin D analogue, Alfacalcidol is converted rapidly in the liver to 1,25-dihydroxyvitamin D3 (Calciterol -the metabolite of vitamin D) and does not require renal hydroxylation as Vitamin D administration. Alfacalcidol
acts as a regulator of calcium and phosphate metabolism and increases their intestinal absorption , hence it helps in bone
mineralization. The major advantage of Alfacalcidol is that it has rapid onset of response and if hypercalcaemia occurred due to its
administration, it can be treated within days of stopping treatment.
INDICATIONS:
- Alfacalcidol is indicated for treatment of renal osteodystrophy caused by reduced endogenous production of 1,25-dihydroxyvitamin D3 in consequence of impaired kidney function.
- For treatment of osteomalacia in adults and rickets in children caused by vitamin D deficiency due to inadequate exposure to
sunlight , lack of vitamin D in nutrition or malabsorption.
- Postmenopausal osteoporosis and steroid induced osteoporosis.
- Hypoparathyroidism and as adjunct to hyperparathyroidism management .
DOSAGE & ADMINISTRATION:
Initial dose for all indications:
Adults and children over 20kg of bodyweight : 1 mcg/day.
The elderly : 0.5 mcg/day.
It is important to adjust the dose according to the biochemical response to avoid hypercalcaemia , indices of response are : serum
levels of calcium, alkaline phosphatase, parathyroid hormone , urinary calcium excretion as well as radiographic and histological
investigations.
The daily dose of Alfacalcidol may be increased by increments of 0.25 – 0.5 mcg / day and most adult patients respond to doses
between 1 - 3 mcg/ day. When there is biochemical or radiographic evidence of bone healing, the dose generally decreases.
Maintenance doses : are generally in the range of 0.25 - 1 mcg /day.
RESTRICTIONS ON USE :
Contraindications
- Hypersensitivity to vitamin D or Alfacalcidol.
- Hypercalcaemia, hyperphosphataemia (except when occurring with hypoparathyroidism) or hypermagnesaemia.
Precautions
- Plasma levels of calcium and phosphate should be monitored periodically (monthly).
- Alfacalcidol should be used with caution in patients with renal failure , renal calculi or heart disease.
- If hypercalcaemia occurs , it can be rapidly treated by stopping treatment until plasma calcium levels return to normal level (in
about one week). Alfacalcidol treatment may then be restarted at a reduced dose (half the previous dose).
- Alfacalcidol should be used with phosphate binding agents in patients with reduced kidney function, to avoid calcification that
occurs due to hyperphosphatemia.
Use in Pregnancy and Lactation
Alfacalcidol shouldn’t be used during pregnancy and lactation unless if benefits outweighs the risks and under physician supervision.
DRUG INSTRATCTIONS :
- Alfacalcidol should be used with caution in patients being treated with digitalis preparations.
- Administration of barbiturates or other liver enzyme inducing anticonvulsants may reduce the efficacy of Alfacalcidol.
- Concomitant administration of cholestyramine, sucralfate or large amounts of aluminum containing antacid reduce the efficacy of
Alfacalcidol by decreasing the intestinal absorption of Alfacalcidol.
- Increase risk of developing hypercalcaemia in patients taking diuretics, vitamin D or calcium containing preparations concurrently
with Alfacalcidol .
- It is preferable not to use Magnesium based antacids and laxatives during treatment with Alfacalcidol due to increased risk of
hypermagnesaemia.
ADVERSE EFFECTS:
Hyperphosphataemia may occur (especially in patients with renal failure ) and hypercalcaemia .
OVERDOSAGE :
Hypercalcaemia appears due to overdose associated with headache , anorexia , nausea and vomiting , heartburn, diarrhea , polyuria,
thirst, muscle and bone pain , pruritus, or palpitation. The treatment is by stopping Alfacalcidol administration, the patient should be
given IV fluids and if there is need to loop diuretics or corticosteroids. Electrolytes and calcium levels should be monitored as well
as renal function.
STORAGE INSTRUCTIONS:
Store below 30°C, in a dry place.
PRESENTATION :
Alfacalcidol 0.25 mcg : Pack of 30 soft gelatin capsules and hospital pack of different sizes.
Alfacalcidol 1mcg : Pack of 30 soft gelatin capsules and hospital pack of different sizes.
Alfacalcidol