Q: 63 year old male with End Stage Renal Disease (ESRD) is admitted to ICU with herpes pneumonitis. What precaution should be taken while prescribing Acyclovir?
Answer: To dose after hemodialysis (HD) session
Almost 50-60% of acyclovir is lost in hemodialysis. In ICU, things get trickier when ESRD patients are on continuous renal replacement therapy (CRRT). Acyclovir clearance depends on various factors like filter type and flow rate. Response to acyclovir is more guided by clinical response and side effects, than targeted trough level. Help from pharmacy service should be sought in such situations.
1. Aronoff GR, Bennett WM, Berns JS, et al. Drug Prescribing in Renal Failure: Dosing Guidelines for Adults and Children. 5th ed. Philadelphia, PA: American College of Physicians; 2007.
2. Heintz BH, Matzke GR, Dager WE. Antimicrobial dosing concepts and recommendations for critically ill adult patients receiving continuous renal replacement therapy or intermittent hemodialysis. Pharmacotherapy. 2009;29(5):562-577. doi: 10.1592/phco.29.5.562.