Pimecrolimus

Pimecrolimus is a topical immunosuppressive macrolide that may be used in the treatment of atopic eczema. The mechanism of action of pimecrolimus is not fully understood however it works mainly by reducing inflammation through suppression of T lymphocyte responses.

• pimecrolimus is licensed as a first-line treatment in the UK for atopic eczema - indicated for mild to moderate atopic eczema in adults and children aged 2 years or older, for short-term treatment of signs and symptoms and for intermittent long-term treatment to flares (starting at the first appearance of eczema and continuing until clearance) (1)
• pimecrolimus is moderately effective in atopic eczema although its place in therapy is unclear
• a review has stated stated that there was insufficient evidence that pimecrolimus provided any advantage over less expensive topical corticosteroids ) (1). When pimecrolimus was compared with a potent topical corticosteroid (betamethasone valerate 0.1%) in a phase II study, pimecrolimus was found to be less effective
• also a review states that pimecrolimus is second line treatment for moderate or severe atopic dermatitis in patients who are not adequately responsive to or are intolerant of topical corticosteroids (2)
  • pimecrolimus ointment 0.03% is not recommended for use in children aged 2 years or below. pimecrolimus ointment 0.1% should not be used in children under 16 years of age
  • frequency of administration of pimecrolimus ointment 0.03% in children should be limited to once daily
  • lower strength of pimecrolimus ointment (0.03%), should be used in adults wherever possible
• a Drug and Therapeutics Bulletin (3) notes that "the safety of long-term use of pimecrolimus, in terms of any potential to increase susceptibility to infection or malignancy, needs to be clearly established"
• when comparing with tacrolimus in a commentary concerning the management of atopic eczema, Dr Berth-Jones, consultant dermatologist stated (4):
  • "tacrolimus is more potent than pimecrolimus"
  • ..."while tacrolimus seems likely to be used mainly in the treatment of moderate and severe atopic eczema, pimecrolimus is likely to prove most useful in mild disease and when used to suppress further flares of eczema once the condition has been brought under control with topical steroids"
  • "like corticosteroids, application of the new immunomodulators is generally best avoided on infected skin, including areas affected by warts or molluscum"
• prescribers should use these products so as to minimise patient exposure and thereby reduce risk. The following guidance has been recommended (2):
  • the medicines should be applied thinly and to affected skin surfaces only
  • treatment should be short term; continuous longterm use should be avoided
  • if no improvement occurs (after 6 weeks for tacrolimus ointment, or 2 weeks for pimecrolimus ointment), or if the disease worsens, the diagnosis of atopic dermatitis should be reevaluated and other therapeutic options considered

Reference:

1. MeReC Bulletin (2003);14 (1): 1-4.
2. Current Problems in Pharmacovigilance (2006); 31:1-12.
3. Drug and Therapeutics Bulletin (2003); 41:33-40.
4. Prescriber (2004); 15 (10): 57-61