Source / episode info
- **Episode:**34
- **Title:**Divine Intervention Episode 34 – Antivirals.
- **Published:**2018-06-01
- Source:Episode page
One-liner
This episode provides a comprehensive review of antiviral agents, detailing mechanisms for herpesviruses (acyclovir, ganciclovir), HIV (fusion inhibitors, NRTIs/NNRTIs, integrase inhibitors), hepatitis viruses (NS3/4A and NS5B inhibition), and influenza (neuraminidase inhibition).
High-yield summary
- Herpes Treatment: Acyclovir is a guanosine analog that requires viral thymidine kinase for activation; its mechanism involves incorporating into DNA, where the lack of a 3'-hydroxyl group causes chain termination.
- CMV/HIV Therapy: Ganciclovir is the drug of choice for CMV and is activated by the UL97 kinase. Both ganciclovir and acyclovir can cause bone marrow suppression; if presented with bone marrow suppression due to an antiviral, consider ganciclovir first.
- HIV Entry Blockers: Maraviroc blocks the CCR5 receptor, preventing viral entry into T cells. Enfuvirtide is a fusion inhibitor that prevents the initial membrane fusion of HIV-1 (but not HIV-2).
- Hepatitis C/B: Hep C drugs target non-structural proteins: Bosirevir inhibits NS3/4A, and Sofosbuvir inhibits NS5B. Interferon-alpha is used for both Hep B and C but has significant side effects (e.g., depression history is a relative contraindication).
- Influenza: Neuraminidase inhibitors (Oseltamivir/Zanamivir) prevent the release of new viral particles by blocking the enzyme responsible for cleaving the sialic acid "feather." Treatment must be initiated within 48 hours and only reduces symptoms, not curing the infection.
Learning objectives
- Differentiate the mechanisms of action and clinical uses of acyclovir vs. ganciclovir in treating herpesviruses.
- Understand the role of CCR5 co-receptor blockade (Maraviroc) versus fusion inhibition (Enfuvirtide) in HIV management.
- Identify the specific viral proteins targeted by modern Hepatitis C drugs (NS3/4A and NS5B).
- Recognize that neuraminidase inhibitors are effective against both Influenza A and B, unlike older agents.
- Differentiate between interferon types: Alpha (Hep B/C), Beta (MS), and Gamma (CGD/Osteopetrosis).
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