The content on or accessible through Medpedia.com is for informational purposes only. Medpedia is not a substitute for professional advice or expert medical services from a qualified health professional. Read more

Doxercalciferol

Lead Editors

(Become a Lead Editor)

There are currently no Lead Editors of this article.

Ask a Question on This Topic

Important Resources for Doxercalciferol:

There is 1 user following this page.

Doxercalciferol is a synthetic analog of vitamin D and is marketed by Genzyme as the prescription drug Hectorol. It is used for the treatment of secondary hyperparathyroidism in patients with chronic kidney disease (CKD).


Contents

Uses

Doxercalciferol is indicated for treatment of secondary hyperparathyroidism (elevated parathyroid hormone (PTH) levels) in patients who are either on dialysis for CKD or not on dialysis but with stage 3 or stage 4 chronic kidney disease.

How Doxercalciferol is Taken

Hecterol is available in oral capsules of 0.5 and 2.5 µg, and for intravenous injection in ampoules of 2 and 4 µg.

In dialysis patients

The recommended initial dose of doxercalciferol in dialysis patients is 10 µg administered three times weekly at dialysis (approximately every other day). The dose is adjusted in response to blood levels of calcium and phosphorus.

In non-dialysis patients

The recommended initial dose of doxercalciferol for non-dialysis patients is 1 µg administered once daily. This may be adjusted later.

How Doxercalciferol Works

Vitamin D metabolites control the absorption of calcium from the gut, the tubular reabsorption of calcium by the kidney and, in conjunction with parathyroid hormone (PTH), the mobilization of calcium from the skeleton. They act directly on bone cells to stimulate skeletal growth, and on the parathyroid glands to suppress PTH synthesis and secretion.

In patients with chronic kidney disease (CKD), deficient production of vitamin D metabolites leads to a condition called secondary hyperparathyroidism, in which the parathyroid gland produces excess parathyroid hormone (PTH). This excess PTH contributes to the development of metabolic bone disease.

Doxercalciferol acts to replace this deficient production of vitamin D metabolites. The drug is converted to an active vitamin D metabolite by the body and acts by reducing the production of excess PTH by the parathyroid gland. This reduces the development of metabolic bone disease.

Similar drugs are available for secondary hyperparathyroidism. Calcitriol is effective, but can cause hypercalcemia and hyperphosphatemia, which require frequent monitoring. Paricalcitol effectively suppresses PTH with minimal impact on serum calcium and phosphorus.[1]

How the Body Affects Doxercalciferol

Doxercalciferol is absorbed from the gastrointestinal tract after ingestion and activated by the liver enzyme CYP 27 to form 1a,25-(OH)2D2 (major metabolite) and 1a,24-dihydroxyvitamin D2 (minor metabolite). Peak circulating levels of the major metabolite are attained at 11-12 hours after repeated doses.

Side Effects

The most common side effects (occurring in >2% of treated patients) are:

  • Abscess
  • Headache
  • Malaise
  • Bradycardia (slow heart rate)
  • Anorexia (loss of appetite)
  • Constipation
  • Dyspepsia (indigestion)
  • Nausea/Vomiting
  • Arthralgia (joint aches)
  • Edema (fluid retentive swelling)
  • Weight increases
  • Dizziness
  • Sleep disorders
  • Dyspnea (shortness of breath)
  • Pruritus (itching)

Risks and Precautions

Use of doxercalciferol may result in hypercalcemia (high blood calcium levels). It has been associated with significant elevations in serum phosphorus requiring greater use of oral phosphate binders.

The signs of hypercalcemia are:

  • Nausea and vomiting
  • Excessive thirst
  • Frequent urination
  • Constipation
  • Abdominal pain
  • Muscle weakness
  • Muscle and joint aches
  • Confusion
  • Lethargy and fatigue

Drug Interactions

Specific drug interaction studies have not been conducted to date.

Magnesium-containing antacids are not be used concurrently with doxercalciferol since this may lead to abnormally high blood magnesium levels.

Effectiveness

The effectiveness of doxercalciferol is measured by its ability to reduce PTH levels (which are the result of secondary parathyroidism).[2]

In dialysis patients

Two studies in dialysis patients demonstrated that doxercalciferol treatment resulted in significant reduction in PTH levels during the treatment period in more than 93.5% of treated patients.

In non-dialysis patients

Two studies in non-dialysis patients demonstrated that doxercalciferol treatment resulted in PTH suppression of ≥ 30% in 74% of treated patients as opposed to only 7% of placebo-treated patients.

References

  1. ↑ Andress DL, Coyne DW, Kalantar-Zadeh K, Molitch ME, Zangeneh F, Sprague SM. Management of secondary hyperparathyroidism in stages 3 and 4 chronic kidney disease. Endocr Pract. 2008 Jan-Feb;14(1):18-27. Abstract
  2. ↑ Drug monograph

External Links

To suggest changes to this page, you must create an account on Medpedia.

The content on or accessible through Medpedia.com is for informational purposes only. Medpedia is not a substitute for professional advice or expert medical services from a qualified health professional. Read more

See Also