How can ritonavir or itraconazole affect systemic exposure to clobetasone butyrate?

Ritonavir or itraconazole can inhibit CYP3A4-mediated corticosteroid metabolism, increasing systemic exposure to clobetasone butyrate; clinical relevance depends on the corticosteroid dose and administration route and the CYP3A4 inhibitor’s potency.