Pimecrolimus

Pimecrolimus is an immunosuppressant and a calcineurin inhibitor. Pimecrolimus is used as a second-line agent for the treatment of mild to moderate atopic dermatitis where first-line therapy has failed. It is used exclusively as a cream for topical application.

It is a very lipophilic macrolide-type compound. The compound was first isolated from fermented ascomycota. Pimecrolimus was developed and first marketed by Novartis.

Pharmacodynamics

Like tacrolimus, pimecrolimus belongs to the ascomycin class of macrolactam immunosuppressants and acts by inhibiting T-cell activation via the calcineurin pathway and inhibiting the release of numerous inflammatory cytokines, thereby preventing the cascade of immune and inflammatory signals. At the molecular level, pimecrolimus at nanomolar concentrations inhibits the synthesis of the cytokines interleukin-2 and interferon gamma (Th1 type) and interleukin-4 and interleukin-10 (Th2 type) in human T cells. In addition, pimecrolimus prevents the release of inflammatory cytokines and mediators from mast cells. Pimecrolimus has a similar mode of action to tacrolimus, but is more selective and has no effect on dendritic cells (Langerhans cells).

Pharmacokinetics

Due to the low systemic absorption of pimecrolimus after topical application, no reliable information on systemic pharmacokinetic parameters can be given.

Side effects

Common side effects of Pimecrolimus topical may include:

• Burning
• Stinging or soreness of the treated skin (especially in the first few days of treatment)
• Increased likelihood of skin infection
• Runny or stuffy nose
• Headache
• Fever
• Chills
• Body aches
• Sore throat
• Cough
• Swollen glands

Contraindications and precautions

It is not known whether Pimecrolimus may harm an unborn child when used topically. In case of an existing pregnancy, the treating physician should be informed in any case.