Okay. Lots to talk about here ... first and foremost that UTI.
This is so very important ... did the vet do a Culture & Sensitivity test on your dog's urine BEFORE prescribing an antibiotic? If you aren't certain, ask them about it straight away and ask for a copy of the test results if they say they did do it.
The phosphate binder (aluminium hydroxide gel powder) is a good one and should help get control of rising phosphorous over several days, maybe a week or two.
Red blood cells in urine could be due to many things, but also the UTI. It is worth checking if the vet did a test for anaemia (low RBC test result would suggest it). The loss of red blood cells can cause anaemia and it will certainly need treating as a priority if it is evident.
What is the blood pressure medication prescribed? Is this for actual high blood pressure - or simply to help push more blood through the circulatory system/increase blood volume? Please ask about this if you are uncertain, as the type of blood pressure medication is different for each.
With a creatinine of 6 and BUN at 118, Brewer's health is seriously undermined. Personally, I would like to see him having IV fluid therapy for a couple of days - followed by SubQ fluid therapy you can give at home. Of course, this is a difficult decision, because things may take a turn for the worse while he is at the vets ... but at the same time, the IV fluids are the best and fastest chance of lowering these high values.
What food has the vet given/suggested?
It's good he's drinking water - please make sure it is filtered ft or bottled water, as this will have less sodium and chemicals in it.
I'll give you a link below to two of my articles on changing diet which you should find useful. Please have a read of them:
http://www.infobarrel.com/How_Diet_Affects_Dogs_with_Chronic_Kidney_Disease
http://www.infobarrel.com/Changing_Diet_During_Canine_Kidney_Disease
That's probably enough for you to be thinking about right now. Get back with answers when you can.
Tony
Just an update, I received all her lab values
CREA- 6
Phos- 8.6
BUN- 118
Protein in urine- 7.1
Red blood cells in urine
Starting her on an antibiotic to treat possible UTI, and a blood pressure medication