Virucidal effect of mouthwash on acyclovir‐resistant herpes simplex virus

Objectives The symptoms of herpes simplex viruses type 1 (HSV‐1) infections might be severe and persistent in immunocompromised patients in whom they reactivate at a high frequency. The development of Acyclovir (ACV) resistant strains due to long‐term treatment with antiviral agents in those patients is not uncommon. The aim of the present study was to assess the virucidal effect of commercially available mouthwashes against ACV‐resistant HSV‐1 strains. Materials and Methods Two acyclovir‐resistant HSV‐1 strains were exposed for 30 s to essential oil‐based (Listerine Fresh Burst® and Listerine Zero®), chlorhexidine gluconate 0.2% (Hexidyl®) and povidone‐iodine 7.5% (Betadine Gargle®) mouthwashes. Loss of virus infectivity was determined by means of plaque reduction assays in a cell culture system. Results All 4 of the tested solutions significantly reduced virus infectivity, with the essential oil‐based and povidone‐iodine mouthwashes being slightly more efficacious, compared to chlorhexidine. Conclusion The findings of this analysis revealed that the tested oral rinses demonstrated in‐vitro antiviral activity against ACV‐resistant HSV. Comparative clinical trials are required to establish the clinical effectiveness of daily use of oral rinses in reducing the appearance of oral HSV lesions in immunocompromised patients.