urgent please help ! very low urine output

Dear All,

My dad is having very low urine output since a few days so much so the color of the urine in the urine bag has turned blackish a couple of times it then improved but today again is it very low about 700ml or so in 20 hrs. He is diabetic since 20yrs but blood sugar has faily been under control with food and minimal medicine since 5 years..Right now he is on IV fluids 60ml/hr since two weeks as he is having difficulty swallowing drinking liquids in large amounts either due to Parkinson's/stroke(?)/oral thrush or all of them.Just finished a 10day course of IV antibiotics(Zosyn)yesterday for Pnuemonia. He is on Arnica 30c 3x a day by sucussion method since two weeks and in the last few days have given him one or two doses of the following medicines..Ignatia 30c,R5,Bellodana 30c,Arsenic 30c.He cannot explain because of dementia but keeps clutching in the right flank and lower quadrant area...his Sodium level had fallen to 120 and he was lethargic at that time. he was making lots of urine at that time...now it is the opposite..He has cancer of the Prostate and the bladder is affected too which si being treated by natural therapies.Please suggest a remedy for his kidney so that his pain and function will be taken care of and he will feel better. Thank you.