Alfacalcidol

Registered South African indications:

• Renal bone disease
• Hypoparathyroidism
• Secondary hyperparathyroidism
• Rickets and osteomalacia

Contraindications

• Hypersensitivity to the active ingredient or any of its excipients
• Hypercalcaemia
• Metastatic calcification

Cautions

• Pregnancy
• Breastfeeding
• Renal impairment
• Elderly
• Children
• Arteriosclerosis
• Cardiac valve sclerosis
• Nephrolithiasis
• Pulmonary calcification
• Granulomatous disease
• Sarcoidosis
• Allergy to sesame oil
• Ability to drive and operate machinery

Forms avail. in SA and covered in this monograph: cap

Renal bone disease
Hypoparathyroidism
Secondary hyperparathyroidism
Hypophosphataemic vitamin D-resistant rickets and osteomalacia
Pseudodeficiency rickets
Nutritional and malabsorptive rickets and osteomalacia 

• Oral (cap): Initial: 1μg, dly; Titrate by 0.25-0.5μg according to plasma calcium levels; Usual maintenance dose: 0.25-1μg, dly

If hypercalcaemia occurs, alfacalcidol should be stopped until plasma calcium returns to normal then restarted at half the dose

Patients with marked bone disease may tolerate a higher dose without developing hypercalcaemia

Paed. forms avail. in SA and covered in this monograph: cap

Renal bone disease
Hypoparathyroidism
Secondary hyperparathyroidism
Hypophosphataemic vitamin D-resistant rickets and osteomalacia
Pseudodeficiency rickets
Nutritional and malabsorptive rickets and osteomalacia

Children < 20kg

• Oral (cap): 0.05μg/kg, dly

Children > 20kg

• See adult dosage

Neonatal hypocalcaemia

• Oral (cap): 0.05-0.1μg/kg, dly

Prophylaxis of neonatal hypocalcaemia in preterm neonates

• Oral (cap): 0.1μg/kg, dly

Pregnancy Category

• Caution
• There is a limited amount of data from the use of alfacalcidol in pregnant women. Studies in animals have shown reproductive toxicity at high doses. Therefore, alfacalcidol is not recommended during pregnancy and in women of child-bearing potential not using contraception

Breastfeeding

• Caution; not recommended
• Although it has not been established, it is likely that increased amounts of 1,25-dihydroxyvitamin D will be found in the milk of breastfeeding mothers treated with alfacalcidol. This may influence calcium metabolism in the infant. Consequently, breast-fed infants of alfacalcidol-using mothers should be monitored closely for hypercalcaemia

Fertility

• There are no clinical studies on the effect of alfacalcidol on fertility. A pre-clinical study did not show an effect on fertility in rats

Renal Impairment

• Caution; no dose adjustment recommended

Hepatic Impairment

• No dose adjustment recommended

Elderly

• Caution; dose adjustment recommended
• Initial: 0.5μg, dly

Porphyria Information

• Probably not porphyrinogenic (PNP)

Drugs in Sport

• Permitted - No warnings

Central Nervous System Disorders

• Headache
• Dizziness
• Fatigue
• Confusional state

Gastrointestinal Disorders

• Abdominal pain
• Diarrhoea
• Nausea and vomiting
• Constipation

Genitourinary Disorders

• Nephrocalcinosis
• Nephrolithiasis
• Acute renal failure
• Renal impairment
• Hypercalciuria

Endocrine and Metabolic Disorders

• Hypercalcaemia
• Hyperphosphataemia

Musculoskeletal Disorders

• Myalgia

Skin and Subcutaneous Tissue Disorders

• Pruritus
• Rash
• Urticaria
• Calcinosis

• Digoxin
• Thiazide diuretics
• Calcium-containing preparations
• Vitamin D-containing preparations
• Anticonvulsants
• Barbituates
• Phenytoin
• Carbamazepine
• Primidone
• Magnesium-containing antacids
• Aluminium-containing preparations
• Aluminium hydroxide
• Sucralfate
• Bile acid sequestrants
• Cholestyramine

• Plasma calcium
• Plasma phosphate
• Renal function
• Alkaline phosphatase
• Parathyroid hormone
• Urinary calcium excretion

Therapeutic use

• Renal bone disease: Patients with relatively high initial plasma calcium levels may have autonomous hyperparathyroidism, often unresponsive to alfacalcidol. Other therapeutic measures may be indicated. Before and during treatment with alfacalcidol, phosphate binding agents should be considered to prevent hyperphosphataemia v
• Neonatal hypocalcaemia: Whilst ionised serum calcium levels may provide a guide to response, measurement of plasma alkaline phosphatase activity may be more useful. Levels of alkaline phosphotase approximately 7.5 times above the adult range indicates active disease

Alfacalcidol is converted rapidly in the liver to 1,25-dihydroxyvitamin D, effectively bypassing renal metabolic conversion. This is the metabolite of vitamin D which acts as a regulator of calcium and phosphate metabolism. Since this conversion is rapid, the clinical effects of alfacalcidol and 1,25-dihydroxyvitamin D are very similar. Alfacalcidol promotes intestinal absorption of calcium and phosphorous, resorption of calcium from the bone, and possibly renal reabsorption of calcium.

Capsule 0.25μg

• One-Alpha (Adcock) originator
• Zodoray (Strides Pharma SA)

Capsule 1μg

• One-Alpha (Adcock) originator
• Zodoray (Strides Pharma SA)