Ergocalciferol Drug Information

Ergocalciferol is indicated for use in the treatment of hypoparathyroidism, refractory rickets, also known as vitamin D resistant rickets, and familial hypophosphatemia.

NARROW. Vitamin D Resistant Rickets: 12,000 to 500,000 USP units daily. Hypoparathyroidism: 50,000 to 200,000 USP units daily concomitantly with calcium lactate 4 g, six times per day. DOSAGE MUST BE INDIVIDUALIZED UNDER CLOSE MEDICAL SUPERVISION. Calcium intake should be adequate.

Blood calcium and phosphorous determinations must be made every 2 weeks or more frequently if necessary. X-rays of the bones should be taken every month until condition is corrected and stabilized.

• Hypervitaminosis D is characterized by effects on the following organ system: Renal: Impairment of renal function with polyuria, nocturia, polydipsia, hypercalciuria, reversible azotemia, hypertension, nephrocalcinosis, generalized vascular calcification, or irreversible renal insufficiency which may result in death. CNS: Mental retardation.
• Soft Tissues: Widespread calcification of the soft tissues, including the heart, blood vessels, renal tubules, and lungs.
• Skeletal: Bone demineralization (osteoporosis) in adults occurs concomitantly. Decline in the average rate of linear growth and increased mineralization of bones in infants and children (dwarfism), vague aches, stiffness, and weakness.
• Gastrointestinal: Nausea, anorexia, constipation.
• Metabolic: Mild acidosis, anemia, weight loss. To report SUSPECTED ADVERSE REACTIONS, contact Bionpharma Inc. at 1-888-235-2466 or FDA at 1-800-FDA-1088 or www.fda.gov/ medwatch.

Drug Interactions Mineral oil interferes with the absorption of fat-soluble vitamins, including vitamin D preparations. Administration of thiazide diuretics to hypoparathyroid patients who are concurrently being treated with ergocalciferol may cause hypercalcemia.

Pregnancy Category C Animal reproduction studies have shown fetal abnormalities in several species associated with hypervitaminosis D. These are similar to the supravalvular aortic stenosis syndrome described in infants by Black in England. This syndrome was characterized by supravalvular aortic stenosis, elfin facies, and mental retardation. For the protection of the fetus, therefore, the use of vitamin D in excess of the recommended dietary allowance during normal pregnancy should be avoided unless, in the judgment of the physician, potential benefits in a specific, unique case outweigh the significant hazards involved.

The safety in excess of 400 USP units of vitamin D daily during pregnancy has not been established.

Pediatric Use Pediatric doses must be individualized (see DOSAGE AND ADMINISTRATION ).

Ergocalciferol is contraindicated in patients with hypercalcemia, malabsorption syndrome, abnormal sensitivity to the toxic effects of vitamin D, and hypervitaminosis D.

The effects of administered vitamin D can persist for two or more months after cessation of treatment. Hypervitaminosis D is characterized by: Hypercalcemia with anorexia, nausea, weakness, weight loss, vague aches and stiffness, constipation, mental retardation, anemia, and mild acidosis. Impairment of renal function with polyuria, nocturia, polydipsia, hypercalciuria, reversible azotemia, hypertension, nephrocalcinosis, generalized vascular calcification, or irreversible renal insufficiency which may result in death.

Widespread calcification of the soft tissues, including the heart, blood vessels, renal tubules, and lungs. Bone demineralization (osteoporosis) in adults occurs concomitantly. Decline in the average rate of linear growth and increased mineralization of bones in infants and children (dwarfism). The treatment of hypervitaminosis D with hypercalcemia consists in immediate withdrawal of the vitamin, a low calcium diet, generous intake of fluids, along with symptomatic and supportive treatment.

Hypercalcemic crisis with dehydration, stupor, coma, and azotemia requires more vigorous treatment. The first step should be hydration of the patient. Intravenous saline may quickly and significantly increase urinary calcium excretion.

A loop diuretic (furosemide or ethacrynic acid) may be given with the saline infusion to further increase renal calcium excretion. Other reported therapeutic measures include dialysis or the administration of citrates, sulfates, phosphates, corticosteroids, EDTA (ethylenediaminetetraacetic acid), and mithramycin via appropriate regimens. With appropriate therapy, recovery is the usual outcome when no permanent damage has occurred.

Deaths via renal or cardiovascular failure have been reported. The LD 50 in animals is unknown. The toxic oral dose of ergocalciferol in the dog is 4 mg/kg.