High Serum Level. Is suggested?

My father has one kidney by birth and following is his latest report.His creatinine level is 1.8 and serum urea is 80 mg/dl He has right back side pain for last 4 days. His weight is 89 kg.Is this serum urea high to a dangerous level? What treatment is suggested?  He is a diabetic type 2 patient,a hypertension patient since 15 years and a cholesterol patient as well.Doctor didn't prescribe him any medicine regarding Diabetes and asked him to control it through diet and exercise.Some medicines he's been taking for several years are Amlodipine Besylate, Hydrochlorothiazide/Lisinopril ( in combination) and Atenolol,Lipiget(Atorvastatin),Citanew(Escitalopram),Ascard (Aspirin),Fenoget (Fenofibrate),Neurobion ( Vit B1,B6,B12).Other than this he's been taking Centrum (supplements) as well.