The present invention provides compositions and methods for treating, preventing, and inhibiting viral replication, viral infections and viral diseases and disorders, comprising use of artemisone in combination with at least one antiviral compound selected from maribavir, cidofovir, brincidofovir, valganciclovir, and letermovir, and the combination provides a synergistic anti-viral effect. The invention also provides compositions and methods for treating, preventing, and inhibiting viral replication, viral infections and viral diseases and disorders, comprising the use of artemisone in combination with ganciclovir, wherein the molar ratio between artemisone and ganciclovir is about 1:100 to 100:1, and the combination provides a synergistic anti-viral effect. Pharmaceutical compositions comprising artemisone and at least one of said antiviral compounds are provided as well.