dihydrotachysterol(redirected from Vitamin D4)
Also found in: Dictionary.
Sterol(s) formed by ultraviolet irradiation of any 5,7-diene-3β-sterol, which breaks the 9,10 bond, but usually from either or both of ergosterol and lumisterol to produce tachysterol2 (ertacalciol, (6E,22E)-9,10-secoergosta-5(10),6,8,22-tetraen-3β-ol) and from 7-dehydrocholesterol to produce tachysterol3 (tacalciol, (6E,3S)-9,10-secocholesta-5(10),6,8-trien-3β-ol). When reduced to the 5,7-diene (or 5,7,22-triene) form, dihydrotachysterol3 (10,19-dihydrocalciol) or dihydrotachysterol2 (10,19-dihydroercalciol), antirachitic action appears. This property has been of therapeutic interest, but tachysterol is being replaced by the true vitamin D hormone (calcitriol) and its derivatives.
dihydrotachysterol/di·hy·dro·tach·ys·te·rol/ (-tak-is´ter-ol) an analogue of ergocalciferol that raises serum calcium levels, used in the treatment of hypocalcemia, hypophosphatemia, rickets, and osteodystrophy associated with a variety of disorders and the prophylaxis and treatment of postoperative or idiopathic tetany.
n. Abbr. DHT
A rapidly acting form of vitamin D, C28H45OH, prescribed in the treatment of hypocalcemia.
a rapid-acting form of vitamin D.
indications It is prescribed in the treatment of hypocalcemia resulting from hypoparathyroidism and pseudohypoparathyroidism.
contraindications Hypercalcemia, hypocalcemia with kidney insufficiency, hyperphosphatemia, or known hypersensitivity to this drug or to vitamin D prohibits its use. Caution is advised for lactating mothers.
adverse effects The most serious adverse reaction is hypercalcemia. With overdosage, calcification of soft tissues, including those of the heart, or cardiovascular or kidney failure may occur.
dihydrotachysterolA vitamin D analogue drug used to treat low blood calcium. A brand name is A.T. 10.
a synthetic steroid derived from tachysterol; an antihypocalcemic agent used in the treatment of hypoparathyroidism.