Medications that suppress viral replication and infection【582224797830051†L93-L99】
Explanation
Antivirals are drugs developed to treat infections caused by viruses. Unlike antibiotics, which kill or inhibit bacteria, antivirals do not destroy viruses directly; instead they interfere with specific stages of the viral life cycle to reduce viral load and limit disease progression【582224797830051†L93-L99】. Viruses hijack host cell machinery to replicate, so effective antivirals must selectively inhibit viral proteins or processes while sparing host functions【582224797830051†L110-L113】. Common targets include viral entry receptors, enzymes that copy viral genomes, proteases that process viral polyproteins, and neuraminidases that release new virions. Because viruses mutate rapidly, monotherapy can select for resistant mutants; combination regimens that attack multiple targets are standard for chronic infections such as HIV and hepatitis C【582224797830051†L100-L107】. Antivirals may be used therapeutically to shorten the course of infection and reduce complications, prophylactically to prevent infection in high‑risk individuals or as post‑exposure prophylaxis after known exposure.
Classes and uses
Nucleoside and nucleotide analogues, such as acyclovir, valacyclovir and ganciclovir, mimic natural nucleotides and inhibit viral DNA polymerases to treat herpesviruses and cytomegalovirus. Reverse transcriptase inhibitors (e.g., tenofovir, lamivudine) and integrase inhibitors (e.g., dolutegravir) are core components of antiretroviral therapy for HIV. Protease inhibitors such as ritonavir and glecaprevir block cleavage of viral polyproteins in HIV and hepatitis C. Direct‑acting antivirals for hepatitis C combine polymerase inhibitors (sofosbuvir) with protease and NS5A inhibitors (ledipasvir, velpatasvir) to achieve cure. For influenza, neuraminidase inhibitors (oseltamivir, zanamivir, peramivir) prevent release of virions, while cap‑dependent endonuclease inhibitors (baloxavir marboxil) block viral mRNA synthesis. New antivirals such as remdesivir and nirmatrelvir/ritonavir have been developed to treat COVID‑19. Some antivirals are administered orally, others intravenously or via inhalation.
Through targeted inhibition of viral replication, antiviral drugs improve patient outcomes and reduce transmission, but prudent use and ongoing development are necessary to stay ahead of evolving viruses.
Related Terms: Viruses, Antiviral Resistance, Antimicrobials, Vaccine, Antiretroviral