Ergocalciferol

Pronunciation

Class: Vitamin D
ATC Class: A11CC01
VA Class: VT504
CAS Number: 50-14-6
Brands: Drisdol

Introduction

A vitamin D analog.a

Uses for Ergocalciferol

Hypoparathyroidism and Pseudohypoparathyroidism

Management of hypocalcemia and its clinical manifestations in patients with postsurgical or idiopathic hypoparathyroidism and pseudohypoparathyroidism. a b c d

Familial Hypophosphatemia

Treatment of familial hypophosphatemia (vitamin D resistant rickets). a b c d

Because the large doses of ergocalciferol needed in this disorder often cause toxicity and persistent hypercalcemia, some clinicians prefer dihydrotachysterol or calcitriol and phosphate supplements.c

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Familial Hypophosphatemia associated with Fanconi syndrome

Has been used with treatment of acidosis, to manage hypophosphatemia associated with Fanconi syndrome.a

Nutritional Rickets or Osteomalacia

Has been used in the treatment of nutritional rickets or osteomalacia.a c

Also has been used in the management of tetany and rickets in vitamin D-deficient infants.a c

Anticonvulsant-induced Rickets and Osteomalacia

Has been used in the treatment of rickets or osteomalacia secondary to long-term high-dose anticonvulsant therapy.a c

May be used in the prevention of anticonvulsant-induced rickets and osteomalacia (particularly in those receiving 2 or more anticonvulsants and who have inadequate nutrition and exposure to UV light such as institutional patients).a c Adequate vitamin D supplementation usually prevents associated osteomalacia.

Vitamin D-dependent Rickets

Has been used in the treatment of Vitamin D-dependent Rickets.a c

Renal Osteodystrophy or Hypocalcemia Secondary to Chronic Renal Disease

Has been used in the treatment of early renal osteodystrophy.a c

Osteoporosis

Has been used in conjunction with calcium in the treatment of osteoporosis.a c

Dietary and Replacement Requirements

Adequate intake (AI) (minimum daily intake) of vitamin D is needed to support calcium metabolism and bone health, particularly in the young and old, and thus prevent rickets in children and osteomalacia in adults.

In addition, AI of vitamin D prevents secondary hyperparathyroidism and associated abnormalities in calcium metabolism that can result in porotic bone changes.

Ergocalciferol Dosage and Administration

General

Measure serum calcium, phosphorus, and BUN concentrations every 2 weeks or more frequently if needed.a b d

The manufacturers recommend radiographic examination of the bones in patients with familial hypophosphatemia or hypoparathyroidism every month until the condition stabilizes and is corrected.a b d

Adequate dietary calcium is necessary for clinical response to vitamin D therapy.b d

Administration

Usually administered orally once daily.a May be administered IM in some patients (e.g., those with GI, liver, or biliary disease associated with malabsorption of vitamin D analogs), and according to the manufacturers, these patients should not receive oral ergocalciferol.a

Dosage

Activity of ergocalciferol may be expressed in terms of USP or International Units (IU, units) which are equivalent; 1 unit of vitamin D equals the biologic activity of 25 ng.c

Each mg of ergocalciferol is equivalent to 40,000 USP units; each mcg of the drug is equivalent to 40 USP units.a

Dosage expressed by weight (mg, mcg) or units.a

Dosage depends on nature and severity of hypocalcemia.a c Individualize dosage to maintain serum calcium concentrations of 9–10 mg/dL.a c

Pediatric Patients

Hypoparathyroidism and Pseudohypoparathyroidism
Oral

1.25–5 mg daily with calcium supplements.a

Prolonged administration of dosages >2.5 mg daily may increase risk of toxicity; gradually decrease dosage as serum calcium concentrations approach normal. a

Familial Hypophosphatemia (Vitamin D-Resistant Rickets)
Oral

Initially, 1–2 mg daily with phosphate supplements.a

May increase daily dosage in 250- to 500-mcg increments at 3- to 4-month intervals until an adequate response is obtained.a

After growth is complete, may reduce dosage.a

Familial Hypophosphatemia associated with Fanconi syndrome

625 mcg to 1.25 mg daily have been used. a

Nutritional Rickets and Osteomalacia
Normal GI absorption
Oral

25 mcg daily has been used and resulted in normal serum calcium and phosphate concentrations in about 10 days, radiographic evidence of bone healing within 2–4 weeks, and complete healing within 6 months.a

50–125 mcg daily has been used for 6–12 weeks for more prompt healing.a

May discontinue drug, if healing has occurred with therapy and correction of diet.a

Malabsorption
Oral

Children: 250–625 mcg daily.a

A single 7.5- to 15-mg dose (in oil solution) has been given when compliance was not predictable.a

Infants with tetany and rickets: Initially administer calcium to control tetany then 50–125 mcg daily (until bones have healed) or 250 mcg daily for about 3 weeks.a

Vitamin D-Dependent Rickets
Oral

75–125 mcg daily; some may require up to 1.5 mg daily.a

Renal Osteodystrophy or Hypocalcemia Secondary to Chronic Renal Disease
Oral

0.1–1 mg daily has been used to maintain normal serum calcium concentrations.a

Dietary and Replacement Requirements

AAP recommends that all infants, children, and adolescents have a minimum intake of 400 units daily. Replaces the previous recommendation of a minimum intake (adequate intake) of 200 units daily.

Breastfed or partially breastfed infants: AAP recommended supplemental dosage is 400 units daily; start in the first few days of life. Continue until the child is weaned and consumes ≥1 L or quart of vitamin D-fortified formula or milk daily.

Infants and older children who consume <1 L of vitamin D-fortified formula or milk daily: AAP recommends supplemental dosage of 400 units daily.

Adolescents who do not consume 400 units of vitamin D daily from vitamin D-fortified milk or foods: AAP recommends supplemental dosage of 400 units daily.

Children at increased risk for vitamin D deficiency (e.g., those with fat malabsorption, those receiving anticonvulsant therapy): Higher dosages may be needed.

Adults

Hypoparathyroidism and Pseudohypoparathyroidism
Oral

625 mcg to 5 mg (up to 10 mg) daily with calcium supplements and/or IM or IV PTH.a b d

Prolonged administration of dosages >2.5 mg daily may increase risk of toxicity; gradually decrease dosage as serum calcium concentrations approach normal.a

Familial Hypophosphatemia (Vitamin D-Resistant Rickets)
Oral

250 mcg to 1.5 mg (up to 12.5 mg) daily with phosphate supplementsa c d (usually 1–2 g of elemental phosphorus daily) to maintain serum phosphorus concentrations of at least 3 mg/dL.c

Familial Hypophosphatemia associated with Fanconi syndrome

1.25–5 mg (up to 10 mg) daily have been used along with treatment for acidosis.a

Nutritional Rickets and Osteomalacia
Normal GI absorption
Oral

25 mcg daily has been used resulting in normal serum calcium and phosphorus concentrations in about 10 days, radiographic evidence of bone healing within 2–4 weeks, and complete healing within 6 months.a

50–125 mcg daily has been used for 6–12 weeks for more prompt healing.a

May discontinue drug, if healing has occurred with therapy and correction of diet.a

Severe Malabsorption
Oral

250 mcg to 7.5 mg.a

IM

250 mcg daily.a

Anticonvulsant-Induced Rickets and Osteomalacia
Oral

50 mcg to 1.25 mg daily.a

25 mcg daily or 250 mcg weekly has been used for prevention in those receiving long-term anticonvulsant therapy.a

Vitamin D-Dependent Rickets
Oral

250 mcg to 1.5 mg daily; some may require up to 12.5 mg daily.a

Prolonged administration of dosages >2.5 mg daily may result in toxicity.a

Renal Osteodystrophy or Hypocalcemia Secondary to Chronic Renal Disease
Oral

Initially, 500 mcg daily for early renal osteodystrophy then adjust according to serum calcium concentration.a

May require 250 mcg to 7.5 mg daily (up to 12.5 mg daily to maintain normal serum calcium concentrations).a

Osteoporosis

25–250 mcg daily or 1.25 mg 2 times weekly has been used with calcium and fluoride supplements.a

Dietary and Replacement Requirements

The AI of vitamin D (in terms of cholecalciferol or ergocalciferol) to prevent osteomalacia in healthy adults through 50 years of age is 5 mcg (200 units) daily, while for healthy adults 51–70 or older than 70 years of age is 10 (400 units) or 15 mcg (600 units) daily, respectively.

Because exposure to sunlight is decreased markedly during the winter, adults can become vitamin D deficient. Therefore, to cover the needs of nearly all adults, they should get supplementation. Pregnant and lactating women do not appear to have an increased requirement for vitamin D; however, daily vitamin D supplied by postnatal vitamins is not considered excessive.

Supplemental Dosage in Adults

Age

Geographical Location or other Conditions

AI

19–50 years

Regardless of extent of sun exposure

5 mcg (200 units) daily

51–70 years

Regardless of extent of sun exposure

10 mcg (400 units) daily

>70 years of age

Regardless of extent of sun exposure

15 mcg (600 units) daily

Regardless of age

Severe malabsorption syndromes

250 mcg to 2.5 mg (10,000–100,000 units) daily

Prescribing Limits

Pediatric Patients

Infants and children
Oral

Chronic daily ingestion of 25 mcg daily may result in hypervitaminosis D.c

Adults

Oral

Chronic daily ingestion of 1.25–2.5 mg daily may result in hypervitaminosis D.c

Cautions for Ergocalciferol

Contraindications

  • Hypercalcemia or malabsorption syndrome.b d

  • Malabsorption syndrome.b d

  • Known abnormal sensitivity to toxic effects of vitamin D and hypervitaminosis D.b d

  • Hypervitaminosis.b d

Warnings/Precautions

Warnings

Concomitant Diseases

Administer with extreme caution, if at all, to patients with impaired renal function and with extreme caution in patients with heart disease, renal stones, or arteriosclerosis.c

Hypercalcemia

Acute or chronic administration of excessive doses of vitamin D analogs or enhanced responsiveness to physiologic amounts of ergocalciferol or cholecalciferol may lead to hypervitaminosis D manifested by hypercalcemia.c

Hypersensitivity to vitamin D may be one etiologic factor in infants with idiopathic hypercalcemia.b d Restrict use of vitamin D in these cases. b d

Acute hypercalcemia may increase risk of cardiac arrhythmiasc and seizures,e and result in cardiac arrhythmias in presence of cardiac glycosides.c e

Sensitivity Reactions

Tartrazine Sensitivity

Drisdol capsules contain tartrazine (FD&C yellow No. 5), which may cause allergic-type reactions including bronchial asthma in susceptible individuals. b Incidence of tartrazine sensitivity is low, but it frequently occurs in patients who are sensitive to aspirin.b

General Precautions

Hyperphosphatemia

In patients with hyperphosphatemia (e.g., those with renal osteodystrophy) use a phosphate binder and a low-phosphate diet to control serum phosphate concentrations to prevent metastatic calcification.b d

Specific Populations

Pregnancy

Category C.b d

Lactation

Distributed into milk.b d Caution if used in nursing women.b d Do not administer large doses of vitamin D analogs.c

Pediatric Use

Individualize pediatric doses.b d

Geriatric Use

Insufficient experience in patients ≥65 years of age to determine whether geriatric patients respond differently than younger adults;b however, other experience indicate no substantial differences in safety and efficacy relative to younger adults.b

Select dosage with caution because of age-related decreases in hepatic, renal, and/or cardiac function and concomitant disease and drug therapy.b

Renal Impairment

Administer with caution, if at all, to patients with impaired renal function.c

Common Adverse Effects

Possible hypervitaminosis D effects: polyuria,b d nocturia,b d polydipsia,b d hypercalciuria,b d reversible azotemia,b d hypertension,b d nephrocalcinosis,b d generalized vascular calcification,b d irreversible renal insufficiency (may be fatal),b d mental retardation,b d widespread soft tissue calcification,b d osteoporosis,b d dwarfism,b d vague aches,b d stiffness,b d weakness,b d nausea,b d anorexia,b d constipation,b d mild acidosis,b d anemia,b d weight loss.b d

Interactions for Ergocalciferol

Specific Drugs

Drug

Interaction

Comments

Cardiac glycosides

Concurrent use of vitamin D analogs and cardiac glycosides may result in cardiac arrhythmiasc

Use concomitantly with cautionc

Cholestyramine

Intestinal absorption of the vitamin D analog may be decreasedc

Allow as long a time interval as possible between ingestion of ergocaciferol and cholestytaminec

Colestipol

Intestinal absorption of the vitamin D analog may be decreasedc

Allow as long a time interval as possible between ingestion of the vitamin D analog and colestipolc

Corticosteroids

Corticosteroids may counteract effects of Vitamin D analogsc

Mineral oil

Interferes with absorption of vitamin D preparationsb d

Thiazide diuretics

Risk of hypercalcemia (may be transient and self-limited)c

May require discontinuance of the vitamin D analog c

Phenobarbital

Plasma concentrations of 25-hydroxylated ergocalciferol may be decreasedc

Phenytoin

Plasma concentrations of 25-hydroxylated ergocalciferol may be decreasedc

Orlistat

Potential interaction with drugs affecting lipid absorption (e.g., orlistat), resulting in decreased absorption of the oral vitamin D analog

Allow at least 2 hours between ingestion of the vitamin D analog and orlistat

Ergocalciferol Pharmacokinetics

Absorption

Bioavailability

Readily absorbed (about 80%) from GI tract (mainly in the small intestine);c presence of bile required.c

Onset

Hypercalcemic action: 10–24 hours.c

Maximal hypercalcemic effects occur about 4 weeks after daily administration of a fixed dose.c

Duration

Hypercalcemic action: ≥2 months.c

Special Populations

Extent of GI absorption may be decreased in patients with hepatic, biliary, or GI disease (e.g., Crohn’s disease, Whipple’s disease, sprue).c

Not known whether aging alters GI absorption of physiologic amounts of vitamin D; however, limited data indicate that absoption may be decreased in geriatric patients.b

Distribution

Extent

Enters blood via chylomicrons of lymph and then associates mainly with a specific α-globulin (vitamin D-binding protein).c

25-Hydroxyergocalciferol (metabolite) may be distributed into milk after administration of large doses.c

Elimination

Metabolism

In the liver, metabolized to 25-hydroxy derivatives by vitamin D 25-hydroxylase enzyme;c hepatic microsomal enzymes may be involved in degrading ergocalciferol metabolites.c Further metabolized in kidneys to 1,25 dihydroxyvitamin D.b d

Stability

Storage

Oral

Capsules and Solution

Tight, light resistant containersd at 25°Cb (may be exposed to 15–30°C).a b d

Actions

  • A vitamin D analog.a

  • Ergocalciferol increases intestinal absorption of calcium and phosphate and elevates serum calcium and phosphate concentrations sufficiently to permit bone mineralization.b d

  • Also promotes calcium reabsorption by the kidneys;b c d importance of this effect is not known.c

  • Activated form of ergocalciferol, may have a negative feedback effect on PTH production.c

Advice to Patients

  • Importance of diet and calcium supplementation regimen adherence to achieve a clinical response to vitamin D therapy.c

  • Importance of immediate reporting of potential manifestations of hypercalcemia.c

  • Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs, as well as any concomitant illnesses.b d

  • Importance of women informing clinicians if they are or plan to become pregnant or plan to breast feed.b d

  • Importance of informing patients of other precautionary information.b d (See Cautions.)

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

Ergocalciferol

Routes

Dosage Forms

Strengths

Brand Names

Manufacturer

Bulk

Powder*

Oral

Capsules, liquid-filled

1.25 mg (50,000 units)*

Drisdol (with parabens and tartrazine)

Sanofi-Aventis

Ergocalciferol Capsules

Banner Pharmacaps, Barr

Solution

200 mcg (8000 units) per mL

Calciferol Drops (with propylene glycol)

UCB

Drisdol (with propylene glycol)

Sanofi-Aventis

Ergocalciferol is also commercially available in combination with other vitamins and minerals, analgesic-antipyretics, amino acids, infant formulas, laxatives, and protein supplements.

AHFS DI Essentials. © Copyright, 2004-2014, Selected Revisions February 1, 2009. American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland 20814.

† Use is not currently included in the labeling approved by the US Food and Drug Administration.

References

a. AHFS drug information 2007. McEvoy GK, ed. Ergocalciferol. Bethesda, MD: American Society of Health-Systems Pharmacists; 2007: 3643-4.

b. Sanofi-Synthelabo. Drisdol (ergocalciferol) capsules prescribing information. New York, NY; 2003 Dec.

c. AHFS drug information 2007. McEvoy GK, ed. Vitamin D analogs general statement. Bethesda, MD: American Society of Health-Systems Pharmacists; 2007:3634-40.

d. Banner Pharmacaps. Ergocalciferol capsules prescribing information. High Point, NC; 2005 Dec.

e. Genzyme. Hectorol (doxercalciferol) capsules prescribing information. Cambridge, MA; 2006 Jun.

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