This document summarizes a lecture on antimicrobial agents. It discusses antiviral drugs including mechanisms of action, specific drugs for treating viruses like herpes and influenza, and drug combinations used as highly active antiretroviral therapy (HAART) for HIV/AIDS. It also covers antifungal and anti-parasitic drugs. The key points are that antiviral drugs interfere with viral replication through various mechanisms, and effective treatment requires drugs that can enter infected cells and inhibit viral nucleic acid synthesis or ability to bind host cells.