Q: Why Intravenous acyclovir should be given with adequate hydration and slow rate? 


Answer: To avoid Acyclovir crystalline nephropathy

Intravenous acyclovir may cause reversible nephrotoxicity due to precipitation of acyclovir crystals in the kidney. Risk factors for Acyclovir crystalline nephropathy are rapid infusion, dehydration and preexisting renal dysfunction.