Antiviral Drugs Treatment and Overview PDF
Document Details
Tags
Summary
This document provides an overview of antiviral drugs and their use in treating respiratory viral infections. It covers various types of viruses, such as influenza A and B, and different treatment approaches, including neuraminidase inhibitors. The document also details the mechanism of action and pharmacokinetics of these drugs, along with potential adverse effects.
Full Transcript
Powered by AI Copilot Here is the rewritten version of your text: Antiviral Drugs 1. Overview Viruses: Obligate intracellular parasites Lack: Cell wall, cell membrane, organelles Symptoms: Appear late in the disease...
Powered by AI Copilot Here is the rewritten version of your text: Antiviral Drugs 1. Overview Viruses: Obligate intracellular parasites Lack: Cell wall, cell membrane, organelles Symptoms: Appear late in the disease course Antiviral Drugs: Virustatic Use: Prophylactic agents 2. Treatment of Respiratory Viral Infections Viruses Involved: Influenza A (variety of animal hosts) Influenza B (humans only) Respiratory Syncytial Virus (RSV) Approach: Preferred: Immunization Alternative: Antiviral drugs (for allergies, outbreaks) Influenza A: Characteristics: Causes pandemics (e.g., H1N1) Surface Proteins: Neuraminidase (N), Hemagglutinin (H) Function: H for attachment, N for release 3. Neuraminidase Inhibitors Examples: Oseltamivir, Zanamivir Activity: Influenza A and B Administration: Timing: Prior to exposure or within 48 hours of symptoms Duration: 5-day course Mechanism of Action (MOA): Inhibit neuraminidase Prevent release of new virions Pharmacokinetics (PK): Oseltamivir: Prodrug, oral, activated by hepatic esterases Zanamivir: Active, inhaled Excretion: Urine Adverse Effects: Oseltamivir: Nausea, vomiting, headache Zanamivir: Respiratory discomfort, caution in airway diseases Resistance: Mutations in neuraminidase enzyme 4. Adamantane Antivirals Examples: Amantadine, Rimantadine Activity: Influenza A only Administration: Prior to exposure or within 48 hours of symptoms Mechanism of Action (MOA): Block M2 proton ion channel Block viral uncoating Pharmacokinetics (PK): Amantadine: Excreted unchanged in urine Rimantadine: Extensive metabolism before urinary excretion Note: High resistance, not recommended 5. Ribavirin Characteristics: Guanosine analogue, broad-spectrum Activity: RSV, HCV (with other drugs) Use: Severe RSV bronchiolitis or pneumonia in children/infants Mechanism of Action (MOA): Inhibits RNA and DNA virus replication Formation of 5’-phosphate derivative, triphosphate derivative Inhibits GTP formation, prevents mRNA capping, blocks RNA- dependent RNA polymerase Pharmacokinetics (PK): Administration: Oral, inhalation (aerosolized for RSV) Excretion: Urine Adverse Effects: Dose-dependent anemia Aerosol: Conjunctival or bronchial irritation Contraindications: Pregnancy, conceiving children for 6 months after exposure 6. Treatment of Hepatic Viral Infections Hepatitis Viruses: A, B, C, D, E Common Chronic Causes: HBV: DNA virus HCV: RNA virus Goals: HBV: Suppress HBV DNA, seroconversion of HBeAg, reduce hepatic transaminase levels HCV: Viral eradication Is there anything else you need help with?
