Preventive activity of promethazine against fluconazole-resistant <i>Candida</i> spp. biofilms fixed on urinary catheters

Catheter-associated urinary tract infections (CA-UTI) are among the most prevalent infections, affecting over 150 million individuals worldwide annually. <i>Candida</i> is the most common fungal genus causing urinary infections, representing a significant medical challenge, particularly in patients undergoing prolonged catheterization-a risk factor that exacerbates clinical conditions by promoting the formation of resistant biofilms. In this context, the coating of catheters with antimicrobial substances combined with drug repositioning is an innovative alternative. In this study, we evaluated the activity of promethazine (PMT), a first-generation antihistamine, against the formation of <i>Candida</i> spp. biofilms on urinary catheter fragments. Broth microdilution, impregnation of urinary catheter fragments, and scanning electron microscopy (SEM) were the exploratory techniques employed. PMT proved to be an effective agent in inhibiting biofilm formation, achieving a 50% reduction in colony-forming units (CFU/mL). The results indicated that PMT exhibits high potential as an antifungal agent, with promising applications in coatings aimed at preventing <i>Candida</i> spp. infections associated with long-term urinary devices.