ergocalciferol 1.25 MG Oral Capsule

INDICATIONS AND USAGE Ergocalciferol Capsules, USP are indicated for use in the treatment of hypoparathyroidism, refractory rickets, also known as vitamin D resistant rickets, and familial hypophosphatemia.

DOSAGE AND ADMINISTRATION THE RANGE BETWEEN THERAPEUTIC AND TOXIC DOSES IS 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.

WARNINGS Hypersensitivity to vitamin D may be one etiologic factor in infants with idiopathic hypercalcemia. In these cases vitamin D must be strictly restricted. Keep out of the reach of children.

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

CLINICAL PHARMACOLOGY The in vivo synthesis of the major biologically active metabolites of vitamin D occurs in two steps. The first hydroxylation of ergocalciferol takes place in the liver (to 25-hydroxyvitamin D) and the second in the kidneys (to 1,25-dihydroxy- vitamin D). Vitamin D metabolites promote the active absorption of calcium and phosphorus by the small intestine, thus elevating serum calcium and phosphate levels sufficiently to permit bone mineralization. Vitamin D metabolites also mobilize calcium and phosphate from bone and probably increase the reabsorption of calcium and perhaps also of phosphate by the renal tubules. There is a time lag of 10 to 24 hours between the administration of vitamin D and the initiation of its action in the body due to the necessity of synthesis of the active metabolites in the liver and kidneys. Parathyroid hormone is responsible for the regulation of this metabolism in the kidneys.