Calcipotriol (INN) or calcipotriene (USAN) is a sythetic derivative of calcitriol or Vitamin D.
Indication
For the treatment of moderate plaque psoriasis in adults.
Pharmacology
Calcipotriene is a synthetic analog of vitamin D. In humans, the natural supply of vitamin D depends mainly on exposure to the ultraviolet rays of the sun for conversion of 7-dehydrocholesterol to vitamin D3 (cholecalciferol) in the skin.
Toxicity
Topically applied calcipotriene can be absorbed in sufficient amounts to produce systemic effects. Elevated serum calcium has been observed with excessive use of calcipotriene.
Affected Organisms
Humans and other mammals
Biotransformation
Hepatic. Calcipotriene metabolism following systemic uptake is rapid, and occurs via a similar pathway to the natural hormone. The primary metabolites are much less potent than the parent compound.
Absorption
Clinical studies with radiolabeled ointment indicate that approximately 6% (+3%, SD) of the applied dose of calcipotriene is absorbed systemically when the ointment is applied topically to psoriasis plaques or 5% (+2.6%, SO) when applied to normal skin.
Elimination
The active form of the vitamin, 1,25-dihydroxy vitamin D3 (calcitriol), is known to be recycled via the liver and excreted in the bile. There is evidence that maternal 1,25-dihydroxy vitamin D3 (calcitriol) may enter the fetal circulation, but it is not known whether it is excreted in human milk.