Raniah Al-Jaizani M.Sc Lecturer, Clinical Pharmacy Dept. Dosing of drugs in Renal failure Raniah Al-Jaizani M.Sc Lecturer, Clinical Pharmacy Dept.

Dosing of drugs in Renal failure CASE 1 G.G., a 31 y.o, woman IBW 70 kg with 3 yr hx of SLE, present to ER with 3 days hx of fatigue, weakness, nausea, and fever. Laboratory value: Na= 142 mEq/L (135-144) Srcr= 3.4 mg/dl (0.6-1.2) BUN= 38 mg/dl (7-20) Two weeks into her hospital course, G.G’s condition worse and she develops sings of sepsis. Pseudomonas aeruginosa is cultured from her urine. Therapy with ceftazidime (1g every 24 hr) was initiated. G.G’s medical team decide that the addition of an aminoglycoside is now necessary. How should the gentamicin be dosed in G.G?

Dosing of drugs in Renal failure Case 1 (Answer) Normal dose in sever life-theratening infections: 2-2.5 mg/ kg/dose 90-97 % excreted renally Clcr= 26.7 ml/min Clcr 20-40 ml/min: 100% of normal dose administered every 24 hr So, G.G dose of gentamicin 140 q 24 hr Peak and trough level should be monitored

Dosing of drugs in Renal failure CASE 2 D.M, a 28 y.o, 50 kg man with AIDS present with sever herpetic infection requiring I.V acyclovir. Due to other complication associated with his HIV virus, D.M has developed renal insufficiency during his hospital course. His Srcr= 4.5 mg/dl (0.6-1.2) How should acyclovair be dosed in D.M?

Dosing of drugs in Renal failure Case 2 (Answer) Normal dose=10 mg/kg intravenously over 1 hour, every 8 hours 76-82 % excreted renally Clcr= 17.2 ml/min Clcr 10-25 ml/min: 5-10 mg/kg/dose administered every 24 hr So, D.M acyclovair I.V dose 500 mg I.V infused over 1 hour q 24 hours

Dosing of drugs in Renal failure CASE 3 Huda is medical intern in KKUH call drug information center asking you some question about vancomycin. What is the normal dose of vancomycin? Should vancomycin dose adjusted in renal failure patients? K.A, is 55 y.o female, 80 kg, with MRSA and vancomycin should be initiated what is the dose of vancomycin if her Srcr= 2 mg/dl (0.6-1.2)

Dosing of drugs in Renal failure Case 3 (Answer) Normal dose= 1 g every 12 hr Yes, 80-90 % excreted renally Clcr= 40 ml/min Clcr 40-60 ml/min: start with 1g or 10-15 mg/kg/dose every 24 hr So, K.A dose of vancomycin 1 g I.V infused over 2 hours q 24 hr Peak and trough level should be monitored