Calcipotriol or calcipotriene (USAN

United States Adopted Name

United States Adopted Names are unique nonproprietary names assigned to pharmaceuticals marketed in the United States. Each name is assigned by the USAN Council, which is co-sponsored by the American Medical Association , the United States Pharmacopeial Convention , and the American Pharmacists...

) is a synthetic derivative of calcitriol

Calcitriol

Calcitriol , also called 1,25-dihydroxycholecalciferol or 1,25-dihydroxyvitamin D3, is the hormonally active form of vitamin D with three hydroxyl groups...

 or vitamin D

Vitamin D

Vitamin D is a group of fat-soluble secosteroids. In humans, vitamin D is unique both because it functions as a prohormone and because the body can synthesize it when sun exposure is adequate ....

. It is used in the treatment of psoriasis

Psoriasis

Psoriasis is an autoimmune disease that appears on the skin. It occurs when the immune system mistakes the skin cells as a pathogen, and sends out faulty signals that speed up the growth cycle of skin cells. Psoriasis is not contagious. However, psoriasis has been linked to an increased risk of...

, marketed under the trade name Dovonex or Daivonex.

Mechanism

The efficacy of calcipotriol in the treatment of psoriasis was first noticed by the observation of patients receiving various forms of vitamin D in an osteoporosis study. Unexpectedly, a patient's psoriasis lesions dramatically disappeared.

The precise mechanism of calcipotriol in remitting psoriasis is not well-understood. However, it has been shown to have comparable affinity with calcitriol for the vitamin D receptor (VDR), while being less than 1% as active as the calcitriol in regulating calcium metabolism. The vitamin D receptor belongs to the steroid/thyroid receptor superfamily, and is found on the cells of many different tissues including the thyroid, bone, kidney, and T cell

T cell

T cells or T lymphocytes belong to a group of white blood cells known as lymphocytes, and play a central role in cell-mediated immunity. They can be distinguished from other lymphocytes, such as B cells and natural killer cells , by the presence of a T cell receptor on the cell surface. They are...

s of the immune system. T cells are known to play a role in psoriasis, and it is thought that the binding of calcipotriol to the VDR modulates the T cells gene transcription of cell differentiation and proliferation related genes.

Usage and efficacy

Available as a cream, ointment or scalp solution (50 µg/mL), calcipotriol is applied twice daily to plaque psoriasis on the body or scalp, but not the face. Improvement is usually detectable within 2 weeks. Most patients show some improvement, slightly more so than is seen with the use of corticosteroids alone. Tachyphylaxis

Tachyphylaxis

Tachyphylaxis is a medical term describing a decrease in the response to a drug due to previous exposure to that drug. Increasing the dose of the drug may be able to restore the original response. In this context tachyphylaxis is a synonym for drug tolerance...

 does not occur, an improvement over glucocorticoid therapy.

Side effects

Calcipotriol has been shown in clinical trials to have an excellent safety profile. Reports of hypercalcemia are rare.

It is also available in combination with the synthetic glucocorticoid betamethasone

Betamethasone

Betamethasone is a potent glucocorticoid steroid with anti-inflammatory and immunosuppressive properties. Unlike other drugs with these effects, betamethasone does not cause water retention. It is applied as a topical cream, ointment, foam, lotion or gel to treat itching...

 as betamethasone/calcipotriol

Betamethasone/calcipotriol

Betamethasone/calcipotriol , trade names Taclonex, Dovobet and Daivobet, is a combination drug used as an ointment in the treatment of psoriasis....

.

External links

• Leo Pharmaceuticals Product Monograph- Detailed information from the manufacturers, includes the blood testing recommendation (.pdf document).
• Calcipotriene information - U.S. NLM/NIH