Dihydrotachysterol
Synonym :
Dichysterol
Mechanism :
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.
Indication :
- Acute, chronic, and latent forms of postoperative tetany
- Idiopathic tetany
- Hypoparathyroidism
- Rickets
Contraindications :
Contraindicated in patients with hypercalcemia, abnormal sensitivity to the effects of vitamin D, and hypervitaminosis D.
Dosing :
Hypoparathyroidism:
Neonate Dose:
0.05 to 0.1 mg orally once a day.
Infant and Child Dose:
Initial dose: 1 to 5 mg orally once a day for 4 days. Maintenance dose: 0.5 to 1.5 mg orally once a day.
Renal Osteodystrophy:
0.1 to 0.5 mg orally once a day.
Rickets:
0.5 mg orally one time or 13 to 50 mcg/day until healing occurs.
Adverse Effect :
Hypercalcemia, metastatic calcification, polydipsia, weight loss, nausea, vomiting, anorexia, anemia, weakness, polyuria, kidney damage
Interaction :
Dihydrotachysterol: Administration of thiazide diuretics to hypoparathyroid patients who are concurrently being treated with dihydrotachysterol may cause hypercalcemia.
Hepatic Dose :
No dosage adjustments are recommended.