Quote:
"On average, a kidney transplant from a living donor lasts for 20-25 years, while a kidney from a deceased donor lasts 15-20 years.
This is very variable depending on the age of the donor and patient, and other medical issues".
Source:
https://www.nhsbt.nhs.uk/organ-transplantation/kidney/is-a-kidney-transplant-right-for-you/kidney-transplant-faqs/
So, given that your friend is clearly experiencing problems with the function of his transplanted kidney, it would indeed seem quite likely that "it's on its way out". Some people in that position are suitable for a further transplant but many are simply given the choice between haemodialysis to a schedule like the one your friend is on or daily peritoneal dialysis at home (possibly while sleeping).