Calcineurin inhibitor

What is calcineurin?

Calcineurin is a cellular enzyme that catalyses some processes in activated T-lymphocytes.

What is a calcineurin inhibitor?

A calcineurin inhibitor stops calcineurin working, by binding to proteins in the cells called immunophilins. The results are:

• Reduced release of the cytokine interleukin-2 from the T cells
• Reduced T-cell proliferation.

What are calcineurin inhibitors used for in dermatology?

Calcineurin inhibitors are used topically and systemically to treat various inflammatory skin diseases, especially:

• Atopic dermatitis
• Psoriasis

What are the topical calcineurin inhibitors?

• Pimecrolimus cream
• Tacrolimus ointment

Ciclosporin can be used topically, but must be compounded extemporaneously in New Zealand.

What are the oral calcineurin inhibitors?

• Ciclosporin
• Tacrolimus

What are the risks of a calcineurin inhibitor?

Side effects and risks of the specific calcineurin inhibitor are described in the individual topics.

As a class of drug, the main concern is the effect of calcineurin on kidney function. Suspected reasons for nephrotoxicity include:

• Increased endothelin-1, a vascoconstrictor
• Decreased nitric acid, a vasodilator
• Increased transforming growth factor beta 1, a cause of interstitial fibrosis.

The risk of nephrotoxicity is reduced by:

• Keeping the dose of calcineurin inhibitor as low as possible
• Adding or replacing it with another immune suppressive medication with different side effects and risks.