medications and kidney failure

My 7-year-old cat, Henry, was in acute renal failure one month ago. His weekly blood tests since then have all been normal, except for this last time, when his urine was found to have blood and bacteria. He has also had diarrhea for a few days, and the vet thinks he has both a UTI and gastro-int. infection. She has prescribed both Orbax and Metronidazole for him. My question is: is it safe for a cat with a history of kidney failure to be taking these drugs, and both at the same time?

Thanks!

[Dan Sims, DVM]

Yes it is safe but a culture should be done before instituting antibiotic therapy
to assure the correct antibiotic is used.
Eight weeks minimum for the Orbax and re-culture the urine 10 days later.
The G I tract probably plays no role in this case.