Name: | Calcitriol |
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PubChem Compound ID: | 10093379 |
Description: | The physiologically active form of vitamin D. It is formed primarily in the kidney by enzymatic hydroxylation of 25-hydroxycholecalciferol (CALCIFEDIOL). Its production is stimulated by low blood calcium levels and parathyroid hormone. Calcitriol increases intestinal absorption of calcium and phosphorus, and in concert with parathyroid hormone increases bone resorption. |
Molecular formula: | C27H44O3 |
Molecular weight: | 416.636 g/mol |
Name: | Calcitriol |
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Name (isomeric): | DB00136 |
Drug Type: | small molecule |
Description: | The physiologically active form of vitamin D. It is formed primarily in the kidney by enzymatic hydroxylation of 25-hydroxycholecalciferol (CALCIFEDIOL). Its production is stimulated by low blood calcium levels and parathyroid hormone. Calcitriol increases intestinal absorption of calcium and phosphorus, and in concert with parathyroid hormone increases bone resorption. |
Synonyms: |
1,25-(OH)<sub>2</sub>D3; 1,25-dihydroxycholecalciferol
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Brand: | Rocaltrol, Calcijex, Calcitriol Oral Solution, Decostriol |
Category: | Antihypocalcemic Agents, Antihypoparathyroid Agents, Vitamins, Vitamins (Vitamin D), Calcium Channel Agonists, Essential Vitamin, Bone Density Conservation Agents |
CAS number: | 32222-06-3 |
Indication: | Used to treat 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. |
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Pharmacology: |
Calcitriol, a pharmaceutical form of vitamin D, has anti-osteoporotic, immunomodulatory, anticarcinogenic, antipsoriatic, antioxidant, and mood-modulatory activities. Calcitriol has been found to be effective in the treatment of psoriasis when applied topically. Calcitriol has been found to induce differentiation and/or inhibit cell proliferation i...
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Mechanism of Action: |
The mechanism of action of calcitriol in the treatment of psoriasis is accounted for by their antiproliferative activity for keratinocytes and their stimulation of epidermal cell differentiation. The anticarcinogenic activity of the active form of Calcitriol appears to be correlated with cellular vitamin D receptor (VDR) levels. Vitamin D receptors...
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Absorption: | Rapidly absorbed from the intestine. |
Protein binding: | 99.9% |
Biotransformation: | The first pathway involves 24-hydroxylase activity in the kidney; this enzyme is also present in many target tissues which possess the vitamin D receptor such as the intestine. The end product of this pathway is a side chain shortened metabolite, calcitroic acid. The second pathway involves the conversion of calcitriol via the stepwise hydroxylation of carbon-26 and carbon-23, and cyclization to yield ultimately 1a,25R(OH)2-26,23S-lactone D3. The lactone appears to be the major metabolite circulating in humans. |
Route of elimination: | Enterohepatic recycling and biliary excretion of calcitriol occur. The metabolites of calcitriol are excreted primarily in feces. Cumulative excretion of radioactivity on the sixth day following intravenous administration of radiolabeled calcitriol averaged 16% in urine and 49% in feces. |
Half Life: | 5-8 hours |
Clearance: | 15.3 mL/hr/kg [pediatric patients (age range: 1.8 to 16 years) undergoing peritoneal dialysis receiving dose of 10.2 ng/kg (SD 5.5 ng/kg) for 2 months] |
Toxicity: | LD50 (oral, rat) = 620 μg/kg; LD50 (intraperitoneal, rat) > 5 mg/kg; Overdose evident in elevated blood calcium levels causing symptoms of anorexia, nausea and vomiting, polyuria, polydipsia, weakness, pruritus, and nervousness, potentially with irreversible calcification of soft tissue in the kidney and liver. |
Affected organisms: | Humans and other mammals |
Drug interaction: |
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