DESCRIPTION
Derivative of 7-dehydroxycholesterol formed by ultraviolet rays breaking of the C9-C10 bond. It differs from ergocalciferol in having a single bond between C22 and C23 and lacking a methyl group at C24.
CATEGORIES
Bone Density Conservation Agents,Vitamins,Antithyroid Agents,Vitamin D,Antihypocalcemic Agents.
CHEMICAL FORMULA
C27H44O
COMPOSITION
Chlolecalciferol 60000IU
INDICATION
For the treatment of vitamin D deficiency or insufficiency, refractory rickets (vitamin D resistant rickets), familial hypophosphatemia and hypoparathyroidism, and in the management of hypocalcemia and renal osteodystrophy in patients with chronic renal failure undergoing dialysis. Also used in conjunction with calcium in the management and prevention of primary or corticosteroid-induced osteoporosis.
PHARMACODYNAMICS
Cholecalciferol (vitamin D3) is a steroid hormone that has long been known for its important role in regulating body levels of calcium and phosphorus, in mineralization of bone, and for the assimilation of Vitamin A. The classical manifestations of vitamin D deficiency is rickets, which is seen in children and results in bony deformaties including bowed long bones. Deficiency in adults leads to the disease osteomalacia. Both rickets and osteomalacia reflect impaired mineralization of newly synthesized bone matrix, and usually result from a combination of inadequate exposure to sunlight and decreased dietary intake of vitamin D. Common causes of vitamin D deficiency include genetic defects in the vitamin D receptor, severe liver or kidney disease, and insufficient exposure to sunlight. Vitamin D plays an important role in maintaining calcium balance and in the regulation of parathyroid hormone (PTH). It promotes renal reabsorption of calcium, increases intestinal absorption of calcium and phosphorus, and increases calcium and phosphorus mobilization from bone to plasma.
No Information
ABSORPTION
Readily absorbed
METABOLISM
Within the liver, cholecalciferal is hydroxylated to calcidiol (25-hydroxycholecalciferol) by the enzyme 25-hydroxylase. Within the kidney, calcidiol serves as a substrate for 1-alpha-hydroxylase, yielding calcitriol (1,25-dihydroxycholecalciferol), the biologically active form of vitamin D3.
HALF LIFE
Several weeks
TOXICITY
Hypercalcemia – Early symptoms of hypercalcemia, include nausea and vomiting, weakness, headache, somnolence, dry mouth, constipation, metallic taste, muscle pain and bone pain. Late symptoms and signs of hypercalcemia, include polyuria, polydipsia, anorexia, weight loss, nocturia, conjunctivitis, pancreatitis, photophobia, rhinorrhea, pruritis, hyperthermia, decreased libido, elevated BUN, albuminuria, hypercholesterolemia, elevated ALT (SGPT) and AST (SGOT), ectopic calcification, nephrocalcinosis, hypertension and cardiac arrhythmias.
FOOD INTERACTIONS
avoid alcohol
SIDE EFFECTS
Dry mouth, muscle pain, increased thirst, loss of appetite, vomiting, metallic taste, upset stomach, constipation, difficult urination.