How can ritonavir and itraconazole affect systemic exposure to topical clobetasol propionate?

Ritonavir and itraconazole inhibit CYP3A4 and can reduce corticosteroid metabolism, increasing systemic exposure to topical clobetasol propionate; clinical relevance depends on the corticosteroid dose and administration route and the CYP3A4 inhibitor’s potency.