In a 90-day repeat-dose toxicity study in rats, topical administration of clobetasol propionate foam at dose concentrations from % to % or from to mg/kg/day of clobetasol propionate resulted in a toxicity profile consistent with long-term exposure to corticosteroids including adrenal atrophy, histopathological changes in several organs systems indicative of severe immune suppression, and opportunistic fungal and bacterial infections. A no observable adverse effect level (NOAEL) could not be determined in this study. Although the clinical relevance of the findings in animals to humans is not clear, sustained glucocorticoid-related immune suppression may increase the risk of infection and possibly the risk for carcinogenesis.
Vitiligo is a common skin condition resulting from loss of normal melanin pigments in the skin which produces white patches. Topical corticosteroids are indicated for the treatment of limited areas of vitiligo. Pimecrolimus, which inhibits calcineurin, has recently been shown to be effective for the treatment of vitiligo. We performed a prospective study to evaluate the efficacy of the % clobetasol propionate and 1% pimecrolimus in the treatment of vitiligo. Ten patients with virtually bilateral symmetrical lesions of vitiligo were included. % clobetasol propionate was applied twice daily over the lesion on right side of the body, and topical 1% pimecrolimus was applied twice daily over the lesion on left side of the body. It was determined that both treatment modalities resulted in a comparable rate of repigmentation. Response to treatment was varied according to the anatomical location of the lesions where better results were seen on the trunk and extremities. Results from this pilot study indicate that topical 1% pimecrolimus is as effective as clobetasol propionate in restoring skin disfiguring due to vitiligo. For a better conclusive statement further studies involving larger groups of patients should be performed.