valgancyclovir dosing

Hello, we have a case : 32yo male, cardiac transplant last year with sepsis nand  now requires dialysis. Diagnosed with CMV colitis and was prescribed Valganciclovir. Many references says: not recommended in PD patients, dialysed -to avoid etc.. Is 450 mg twice a week dose appropriate in this case? Cr = 400, eGFR around 15. Thanks.