Clobetasol propionate comes as a foam, spray, cream, gel, ointment, or shampoo. If applying a spray, gel, cream, or ointment to the skin, wash and dry the affected area and your hands before apply the medication. Cover the area with a thin layer of medication and rub it in gently. Allow the medication to dry before covering it with clothing. Do not wrap or bandage the area unless specified by your doctor. If using the clobetasol propionate shampoo to treat the scalp, part your hair to expose the affected area. Apply the shampoo to the affected area only on your dry scalp and massage it in gently. Let the shampoo sit for 15 minutes. Then add water, lather the shampoo in the area and rinse it out well. Because clobetasol propionate is a powerful corticosteroid, it should not be used for more than two weeks and should not be used on face, groin, or arm pit areas. Do not cover the affected area with makeup or cosmetics.
Ritonavir (a strong CYP3A4 inhibitor) significantly increased plasma fluticasone propionate exposure following administration of fluticasone propionate aqueous nasal spray, resulting in significantly reduced serum cortisol concentrations [see CLINICAL PHARMACOLOGY ]. During postmarketing use, there have been reports of clinically significant drug interactions in patients receiving fluticasone propionate and ritonavir, resulting in systemic corticosteroid effects including Cushing syndrome and adrenal suppression. Therefore, coadministration of fluticasone propionate and ritonavir is not recommended unless the potential benefit to the patient outweighs the risk of systemic corticosteroid side effects.
The effect of subcutaneously administered clobetasol propionate on fertility and general reproductive toxicity was studied in rats at doses of 0, , 25, and 50 mcg/kg/day. Males were treated beginning 70 days before mating and females beginning 15 days before mating through day 7 of gestation. A dosage level of less than mcg/kg/day clobetasol propionate was considered to be the no-observed-effect-level (NOEL) for paternal and maternal general toxicity based on decreased weight gain and for male reproductive toxicity based on increased weights of the seminal vesicles. The female reproductive NOEL was mcg/kg/day (ratio of animal dose to proposed human dose of on a mg/m 2 /day basis) based on reduction in the numbers of estrous cycles during the pre-cohabitation period and an increase in the number of nonviable embryos at higher doses.