Why do lung transplant patients discontinue triazole prophylaxis?

Background: Lung transplant recipients are prone to invasive fungal infections prompting many transplant centers to use prolonged triazole antifungal prophylaxis. From a practical standpoint, it is unclear if lung transplant recipients are able to continue prolonged or lifelong prophylaxis without premature discontinuation from side effects, drug interactions, development of fungal disease, or medication cost. We examined the number of patients that are able to reach a prophylactic endpoint and understand the reasons for early termination. Methods: We conducted a retrospective chart review of all lung and heart-lung transplant patients at Mayo Clinic Rochester from May 1, 2002 to December 31, 2017. Type, duration, and reason for discontinuation of triazole prophylaxis were examined. Results: During the study period, 193 patients underwent lung or heart-lung transplantation. Itraconazole, voriconazole, and posaconazole were given to 180, 73, and 60 post-transplant patients, respectively. Providers switched itraconazole to another prophylactic antifungal medication for reasons other than prophylactic completion in 61.8% (126 out of 204) of exposure episodes; this was similar with voriconazole (68.8%, 53 out of 77, P = 0.41). Posaconazole was actively discontinued significantly less often (18.3%, 11 out of 60, P < 0.05). The most common reasons for discontinuing itraconazole were malabsorption (15.5% of exposure episodes) and concern for breakthrough fungal infection (10.2%). In comparison, the most common reason for voriconazole discontinuation was side effect or intolerance (54.5% of VR exposure episodes vs 9.8% of IT exposure episodes, P < 0.05). Conclusions: Itraconazole and posaconazole appeared to have fewer side effects prompting discontinuation than voriconazole, but itraconazole was discontinued more often because of malabsorption and clinical suspicion of fungal infections.