Other drugs associated with myelosuppression or nephrotoxicity (e.g., adriamycin, dapsone, doxorubicin, flucytosine, hydroxyurea, pentamidine, tacrolimus, trimethoprim/ sulfamethoxazole, vinblastine, vincristine, and zidovudine) Unknown Because of potential for higher toxicity, coadministration with valganciclovir should be considered only if the potential benefits are judged to outweigh the risks.
Source: FDA drug label - valganciclovir hydrochloride