Tacalcitol

Tacalcitol is a synthetic vitamin D3 analogue. It is used in the treatment of psoriasis, a chronic skin condition characterized by red, itchy, and scaly patches. Tacalcitol is marketed under several brand names worldwide, including Curatoderm and Bonalfa.

Mechanism of Action[edit]

Tacalcitol works by binding to the vitamin D receptor (VDR) in the skin. This binding activates the receptor, which then regulates the growth and differentiation of skin cells. In psoriasis, the growth of skin cells is abnormally fast, leading to the formation of thick, scaly patches. By slowing down this growth, tacalcitol helps to reduce the symptoms of psoriasis.

Pharmacokinetics[edit]

After topical application, tacalcitol is absorbed into the skin. The extent of systemic absorption is low, which minimizes the risk of systemic side effects. Tacalcitol is metabolized in the liver and excreted in the feces.

Side Effects[edit]

The most common side effects of tacalcitol are skin-related, such as itching, burning, and redness. These side effects are usually mild and go away on their own. Less common side effects include skin discoloration and increased sensitivity to sunlight.

Contraindications[edit]

Tacalcitol should not be used in patients with known hypersensitivity to the drug or any of its components. It is also contraindicated in patients with hypercalcemia or evidence of vitamin D toxicity.

Interactions[edit]

Tacalcitol may interact with other drugs that affect calcium metabolism, such as thiazide diuretics and vitamin D supplements. These interactions can increase the risk of hypercalcemia.

Dosage and Administration[edit]

Tacalcitol is applied topically once daily. The dose may be adjusted based on the patient's response and tolerance. Treatment should be continued as long as necessary to control the symptoms of psoriasis.