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Alfacalcidol parenteral

Updated 2 Feb 2023 | Vitamin D


Solution for injection containing alfacalcidol.

Drugs List

  • alfacalcidol 1microgram/0.5ml injection
  • alfacalcidol 2microgram/1ml injection
  • ONE-ALPHA 1microgram/0.5ml injection
  • ONE-ALPHA 2microgram/1ml injection
  • Therapeutic Indications


    Vitamin D deficiency



    Initial dose: 1microgram daily.
    Maintenance dose range 0.25micrograms to 1microgram daily.


    Initial dose: 0.5microgram daily.
    Maintenance dose range 0.25micrograms to 1microgram daily.


    Children aged 1 month to 18 years

    Children over 20kg:
    Initial dose: 1microgram daily
    Maintenance dose range 0.25microgram to 1microgram daily.

    Children under 20kg:
    Initial dose: 0.05microgram/kg/day.
    Maintenance dose range 0.25microgram to 1microgram daily.

    The following alternative dosing schedule may be suitable:

    Prevention of vitamin D deficiency in renal and cholestatic liver disease (unlicensed)

    Children aged 12 to 18 years: 250nanograms to 500nanograms once daily.
    Children aged 1 month to 12 years, bodyweight over 20kg: 250nanograms to 500nanograms once daily.
    Children aged 1 month to 12 years, bodyweight under 20kg: 15nanograms to 30nanograms/kg (maximum 500nanograms) once daily.


    Treatment of neonatal hypocalcaemia
    50nanograms to 100nanograms/kg/day, up to 2microgram/kg/day in severe cases.

    Prevention of vitamin D deficiency in renal and cholestatic liver disease (unlicensed)
    20nanograms/kg once daily.

    Patients with Renal Impairment

    Initial dosage for adults is 1microgram per dialysis. The maximum recommended dose is 6micrograms per dialysis and not more than 12micrograms per week.
    The injection should be administered into the return line from the haemodialysis machine at the end of each dialysis.

    Additional Dosage Information

    Renal bone disease
    Before and during treatment with alfacalcidol, phosphate binding agents should be considered to prevent hyperphosphataemia.

    Pre-operative treatment with alfacalcidol for 2 to 3 weeks in patients about to undergo parathyroidectomy, alleviates bone pain and myopathy without aggravating preoperative hypercalcaemia.

    Treatment should be continued until alkaline phosphatase levels fall to normal or hypercalcaemia occurs in order to decrease post-operative hypocalcaemia.

    Severe hypocalcaemia is corrected more rapidly with higher doses of alfacalcidol (3micrograms to 5micrograms) together with calcium supplements.

    Hypophosphataemic vitamin D-resistant rickets and osteomalacia
    Phosphate supplements may be required in addition to alfacalcidol in some patients.

    Nutritional and malabsorptive rickets and osteomalacia
    Nutritional rickets and osteomalacia can be cured rapidly with alfacalcidol. Malabsorptive osteomalacia will respond to small doses of alfacalcidol.

    Pseudo-deficiency (D-dependent) rickets and osteomalacia
    Effective doses of alfacalcidol are similar to those required to heal nutritional vitamin D deficiency rickets and osteomalacia.


    To be administered intravenously as a bolus over approximately 30 seconds. Shake the ampoule for a minimum of 5 seconds before use.


    Metastatic calcification

    Precautions and Warnings

    Tissue calcification
    Hereditary fructose intolerance
    Valvular heart disease

    Renal failure increases risk of hypercalcaemia
    Advise patient dizziness may affect ability to drive or operate machinery
    Overdose potential.Prescriber- state dose in micrograms(not mls)+frequency
    Injection contains propylene glycol
    Presentations with sorbitol unsuitable in hereditary fructose intolerance
    Some formulations contain hydroxybenzoate
    Some formulations may contain alcohol
    Some products contain sesame oil
    Some products may contain arachis (peanut) oil
    Breastfeeding: Hypercalcaemia of infant possible if mother taking vitamin D
    Monitor parathyroid hormone levels
    Monitor plasma calcium
    Monitor serum alkaline phosphatase levels periodically
    Monitor serum phosphate levels
    Discontinue if hypercalcaemia occurs
    Female: Ensure adequate contraception during treatment

    Serum calcium and serum phosphate should be monitored regularly especially in children, patients with renal impairment and patients receiving high doses.

    In patients with chronic renal failure prolonged hypercalcaemia may aggravate the decline of renal function.

    Indices of response include plasma levels of calcium (ideally corrected for protein binding), alkaline phosphatase, parathyroid hormone as well as radiographic and histological investigations.

    Use with caution in patients being treated with cardiac glycosides as hypercalcaemia may lead to arrhythmias in these patients.

    Interrupt therapy if hypercalcaemia occurs until plasma levels return to normal (in approximately 1 week). Therapy with alfacalcidol may be restarted at half the previous dose with monitoring of calcium.

    Early symptoms of hypercalcaemia are muscle and bone pain, muscle weakness, confusion, dehydration, anorexia, fatigue, nausea and vomiting , constipation, polyuria, sweating, headache, polydipsia, hypertensionand somnolence.

    Pregnancy and Lactation


    Alfacalcidol is contraindicated in pregnancy.

    Animal studies have shown reproductive toxicity at high doses. As such, alfacalcidol is not recommended during pregnancy and in women of child-bearing potential not using contraception.

    The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( ) or if this is unavailable at the backup site ( ).


    Alfacalcidol should be used with caution in breastfeeding.

    Safety has not been established. It is likely that increased amounts of 1,25-dihydroxyvitamin D will be found in breast milk and may influence the calcium metabolism of breast fed infants.

    Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
    Specialist advice is available from the UK Drugs in Lactation Advisory Service at

    Side Effects

    Abdominal discomfort
    Abdominal pain
    Calcinosis (injection site)
    Renal impairment


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: May 2017

    Reference Sources

    Summary of Product Characteristics: One-Alpha Injection. Leo Laboratories Ltd. Revised March 2017.

    NICE - Evidence Services
    Available at:
    Last accessed: 17 August 2017

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