Pharmacokinetic studies in men with Topicort® (desoximetasone) Ointment % with tagged desoximetasone showed no detectable level (limit of sensitivity: μg/mL) in 1 subject and and μg/mL in the remaining 2 subjects in the blood when it was applied topically on the back followed by occlusion for 24 hours. The extent of absorption for the ointment was 7% based on radioactivity recovered from urine and feces . Seven days after application, no further radioactivity was detected in urine or feces. Studies with other similarly structured steroids have shown that predominant metabolite reaction occurs through conjugation to form the glucuronide and sulfate ester.
There is little evidence as to what percentage of a topical corticosteroid dose is absorbed systemically. Studies investigating systemic effects do not measure how much of the corticosteroid is in the blood, but instead focus on measuring cortisol as a marker of hypothalamic-pituitary-adrenal (HPA) axis suppression. After a few weeks’ treatment with potent or very potent topical corticosteroids temporary HPA axis suppression does occur. However, this resolves upon cessation of the topical corticosteroid, without the need for dose tapering. 5, 19 HPA axis suppression is more marked when topical corticosteroids are applied under occlusion, . with wet wraps.
Long term use of topical corticosteroids can induce tachyphylaxis (tolerance to the vasoconstrictive action of topical corticosteroids). Adverse effects are uncommon when using mild to potent corticosteroids for less than three months, except when used on the face and neck, in intertriginous areas (skin folds), or under occlusion. However, very potent corticosteroids should not be used continuously for longer than three weeks. 2 If longer use of very potent corticosteroids is required, they should be gradually tapered to avoid rebound symptoms and then stopped for a period of at least one week after which treatment can be resumed. 2