Safety and efficacy of foscarnet for the management of ganciclovir-resistant or refractory cytomegalovirus infections: A single-center study

BackgroundInfection with cytomegalovirus (CMV) is an important cause of morbidity and mortality following solid organ transplantation. Resistance to ganciclovir can rarely develop via mutations in UL97 or UL54. There are limited published studies assessing the safety and efficacy of foscarnet for the management of ganciclovir-resistant or refractory cytomegalovirus infection and many centers are reluctant to utilize this important therapy because of concerns about toxicity. MethodsSolid organ recipients transplanted between January 1, 2006 and December 31, 2014 who received at least 1 dose of foscarnet were retrospectively reviewed to assess treatment outcomes, tolerability, and safety of foscarnet. ResultsTen of 31 (32.3%) patients who received foscarnet during the study period died during treatment with foscarnet, whereas all 21 surviving recipients successfully cleared infection. Of these surviving patients, 3 (14.3%) developed significant renal dysfunction, defined as >25% decline in estimated glomerular filtration rate during treatment; one-third had definitive renal biopsy results consistent with foscarnet-induced toxicity. ConclusionAlthough mortality was high in this population, foscarnet use, with proper precautions, was generally safe and significant renal dysfunction was lower than previously reported in other sources, even with extended use.