Viral infections represent a significant challenge in modern medicine due to their rapid spread and diverse clinical manifestations, which considerably impact patient health and public health outcomes. Antiviral therapy constitutes an effective pharmacological approach against viral pathogens and plays a critical role in slowing disease progression and reducing complications. This article analyzes the efficacy of antiviral agents, their pharmacodynamic and pharmacokinetic properties, and their application in various viral infections, including those caused by RNA and DNA viruses. Special attention is given to safety aspects of therapy, including dosing, toxic effects, drug–drug interactions, and risks associated with the patient’s individual pharmacogenetic profile. Study findings indicate that the effectiveness of antiviral therapy depends on the virus type, the patient’s clinical condition, and the individualized adaptation of the treatment strategy. Furthermore, patient monitoring and the development of safety protocols are emphasized to minimize adverse effects during long-term therapy.