Dihydrotachysterol

Toxicity

Toxicity associated with dihydrotachysterol is similar to that seen with large doses of vitamin D.

Chemical properties

White Solid

Originator

Hytakerol,Winthrop,US,1950

The Uses of Dihydrotachysterol

Calcium regulator. Preparation by reduction of Tachysterol. It is widely used for hypocalcemic hypoparathyroidism following surgical removal of parathyroids.

Background

A vitamin D that can be regarded as a reduction product of vitamin D2.

Indications

Used for the prevention and treatment of rickets or osteomalacia, and to manage hypocalcemia associated with hypoparathyroidism or pseudohypoparathyroidism. Also used for the treatment of vitamin D dependent rickets, rickets or osteomalacia secondary to long-term high dose anticonvulsant therapy, early renal osteodystrophy, osteoporosis (in conjunction with calcium), and hypophosphatemia associated with Fanconi syndrome (with treatment of acidosis).

Definition

ChEBI: A hydroxy seco-steroid that is 9,10-secoergosta-5,7,22-triene substituted by a hydroxy group at position 3. A synthetic analogue of vitamin D that acts a bone density conservation agent.

Manufacturing Process

The process of isolating chemically uniform crystalline dihydrotachysterol comprises subjecting the solution of the crude hydrogenation product of tachysterol in benzine to chromatographic adsorption by means of active aluminum oxide while collecting the components having a minor tendency of being adsorbed, subjecting the said components to a repeated chromatographic adsorption and converting the components having a minor tendency of being adsorbed into its ester by treatment with acetic anhydride in pyridine solution, isolating the ester formed from the reaction mixture, subjecting its solution in benzine to chromatographic adsorption while collecting the components having a minor tendency of being adsorbed, recrystallizing these components, saponifying the crystalline ester and recrystallizing the dihydrotachysterol obtained.

brand name

Hytakerol (Sterling Winthrop).

Therapeutic Function

Blood calcium regulator

Pharmacokinetics

Dihydrotachysterol is hydroxylated in the liver to 25-hydroxydihydrotachysterol, which is the major circulating active form of the drug. It does not undergo further hydroxylation by the kidney and therefore is the analogue of 1, 25-dihydroxyvitamin D. Dihydrotachysterol is effective in the elevation of serum calcium by stimulating intestinal calcium absorption and mobilizing bone calcium in the absence of parathyroid hormone and of functioning renal tissue. Dihydrotachysterol also increases renal phosphate excretion.

Veterinary Drugs and Treatments

DHT is used in small animals to treat hypocalcemia secondary to hypoparathyroidism or severe renal disease.

Metabolism

Not Available

Purification Methods

Crystallise the sterol from 90% MeOH, UV: max at 242, 251 and 261nm (E1% 760, 1010 and 650) in EtOH. The acetate has m108-110o and [] +32.8o (CHCl3), UV: max at 242, 251 and 261nm (E 780, 910 and 600) in EtOH. The propionate has m 97-98o and [] +37o (CHCl3), UV: max 242, 251 and 261nm (E 750, 860 and 570) in EtOH. [Werder Hoppe Seyler's Z Physiol Chem 260 119 1939, Windaus et al. Justus Liebigs Ann Chem 499 1978 1932, Beilstein 6 III 2833, 6 IV 3994, 4161.]