Promethazine inhibits efflux, enhances antifungal susceptibility and disrupts biofilm structure and functioning in .

spp. are emerging opportunistic fungi associated with invasive infections, especially in patients with haematological malignancies. The present study investigated the inhibition of efflux pumps by promethazine (PMZ) as a strategy to control and . Planktonic cells were evaluated for antifungal susceptibility to PMZ, as well as inhibition of efflux. The effect of PMZ was also studied in biofilms. PMZ inhibited and planktonic cells at concentrations ranging from 32 to 256 μgml. Subinhibitory concentrations of PMZ inhibited efflux activity in . Biofilms were completely eradicated by PMZ. PMZ potentiated the action of antifungals, affected the morphology, changed the amount of carbohydrates and proteins and reduced the amount of persister cells inside biofilms. The results showed indirect evidences of the occurrence of efflux pumps in and opens a perspective for the use of this target in the control of trichosporonosis.