Before starting

Required

• Baseline
  • Alkaline Phosphatase
  • Parathyroid hormone
  • Serum calcium · ideally corrected calcium for protein binding
  • Serum creatinine (for creatinine clearance)
  • Serum phosphate
  • Urea and electrolytes
  • Vitamin D · (25-hydroxy vitamin D level)

Continued until stable

Required

• Once or twice a week; or whenever nausea and vomiting occurs
  • Serum calcium · ideally corrected for protein binding
  • Serum phosphate

Ongoing once stable

Required

• Every 2 - 4 weeks
  • Alkaline Phosphatase
  • Parathyroid hormone
  • Serum calcium · ideally corrected for protein binding
  • Serum creatinine (for creatinine clearance)
  • Serum magnesium
  • Serum phosphate

Consider

• Every 3 months
  • Alkaline Phosphatase
  • Parathyroid hormone
  • Serum calcium · ideally corrected calcium for protein binding
  • Serum creatinine (for creatinine clearance)
  • Serum magnesium
  • Serum phosphate

Reducing monitoring frequency

Alfacalcidol must not be prescribed without ongoing monitoring of serum calcium and renal function.

However, for stable patients, the licensed recommendation of 2-4 weekly testing may not always be necessary. Consider reducing the frequency to every 3 months, but continue monitoring throughout the duration of therapy.

Abnormal results

Serum calcium

Consider seeking specialist advice and hospital admission if any of:

• Serum calcium less then 1.7 mmol/l
• Serum calcium greater than 3.0 mmol/l
• Patient markedly symptomatic (malaise, thirst, perioral tingling, cramps or tetany)

Notes

Cautions with concomitant medication

Thiazide diuretics and calcium containing preparations

Concurrent use of thiazide diuretics or calcium containing preparations may enhance the risk of hypercalcaemia, therefore calcium levels should be monitored more closely.

Bile acid sequestrants

Concomitant oral administration of bile acid sequestrants, such as colestyramine may impair the intestinal absorption of oral One-Alpha formulations. One-Alpha should be administered at least 1 hour before, or 4 to 6 hours after the intake of the bile acid sequestrant to minimise the potential risk of interaction.

Bibliography

• LEO Laboratories Limited. Summary of Product Characteristics – One-Alpha 0.5microgram soft capsules. Last revised 11/2017 [cited 01/09/2020]
• LEO Laboratories Limited. Summary of Product Characteristics – One-Alpha 2micorgrams/ml oral drops. Last revised 09/2020 [cited 01/09/2020]
• Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press [cited 17/09/2020]
• Stewart M. Alfacalcidol capsules and drops. Patient. Updated Aug 2018 [cited 17/09/2020]
• GP notebook. Vitamin D supplementation (monitoring calcium levels). Updated Dec 2018 [cited 01/09/2020]
• Bath and North East Somerset, Swindon and Wiltshire Clinical Commission Group Area Prescribing Committee Shared Care Protocol for Alfacalcidol. Produced in June 2018

Update history