Encephalopathy Induced by Preventive Administration of Acyclovir in a Man with Symptomatic Multiple Myeloma and Renal Dysfunction.

VACV is often prescribed to patients with multiple myeloma receiving BD therapy to prevent herpes zoster. ACV-induced encephalopathy is commonly observed in patients with renal dysfunction; especially among patients with multiple myeloma with Bence-Jones proteinuria, renal tubules are easily damaged and plasma ACV concentrations are likely to increase and induce ACV-induced encephalopathy. Careful monitoring of the level of consciousness is necessary during preventive ACV therapy in patients with renal dysfunction.