A method of treating viral infections, particularly Hepatitis B (HBV) and Human Immunodeficiency Virus (HIV), by administering a low dose of Elvucitabine to a patient suffering viral infection is provided herein. The Elvucitabine dosages provided herein for effective anti-viral therapy are approximately 10-fold less than the effective dosages of currently marketed reverse transcriptase inhibitors. The Elvucitabine dosage may be given BID, daily, once every 48 hours, or once weekly. Also provided herein are packaged pharmaceutical formulations comprising Elvucitabine and instructions for treating a viral infection by administering a low BID, daily, once/48 hour, or weekly dosage of Elvucitabine. The low dose Elvucitabine formulations provided herein have the additional benefit of improving patient compliance with anti-viral therapy.