Antiviral Drugs Overview

Questions and Answers

Match the following viruses with their characteristics:

Influenza A = Causes pandemics (e.g., H1N1) Influenza B = Humans only RSV = Respiratory viral infection H1N1 = Type of Influenza A strain

Match the antiviral drugs with their types:

Oseltamivir = Neuraminidase inhibitor Zanamivir = Neuraminidase inhibitor Amantadine = Adamantane antiviral Rimantadine = Adamantane antiviral

Match the mode of action with the appropriate antiviral:

Neuraminidase inhibitors = Prevent release of new virions Adamantane antivirals = Block viral uncoating Oseltamivir = Prodrug, oral administration Zanamivir = Inhaled, active form

Match the adverse effects with the corresponding drug:

Oseltamivir = Nausea, vomiting, headache Zanamivir = Respiratory discomfort Amantadine = High resistance Rimantadine = Extensive metabolism before excretion Signup and view all the answers

Match the antiviral drug with its specific pharmacokinetics:

Oseltamivir = Activated by hepatic esterases Zanamivir = Excreted via inhalation Amantadine = Excreted unchanged in urine Rimantadine = Metabolized before urinary excretion Signup and view all the answers

Match the following characteristics of Ribavirin with their descriptions:

Guanosine analogue = A type of compound similar to guanosine Broad-spectrum = Effective against a wide range of viruses Aerosol administration = Delivery method used for RSV Dose-dependent anemia = Side effect that increases with dosage Signup and view all the answers

Match the following Hepatitis viruses with their characteristics:

HBV = DNA virus HCV = RNA virus HAV = Fecal-oral transmission HDV = Requires HBV for replication Signup and view all the answers

Match the following adverse effects of Ribavirin with their descriptions:

Dose-dependent anemia = Reduction in red blood cell count Conjunctival irritation = Discomfort in the eye area Bronchial irritation = Discomfort in the respiratory tract Urinary issues = Effects related to excretion in urine Signup and view all the answers

Match the following mechanisms of action of Ribavirin with their explanations:

Inhibits RNA replication = Prevents the reproduction of RNA viruses Blocks mRNA capping = Prevents the addition of a protective cap to mRNA Formation of triphosphate derivative = Results in altered nucleic acid metabolism Inhibits GTP formation = Reduces availability of guanosine triphosphate Signup and view all the answers

Match the following treatment goals for Hepatitis B and C with their targets:

HBV Goal = Suppress HBV DNA HCV Goal = Achieve viral eradication HBV Objective = Seroconversion of HBeAg HCV Objective = Reduce hepatic transaminase levels Signup and view all the answers

Study Notes

Antiviral Drugs Overview

Viruses are obligate intracellular parasites lacking cell walls, membranes, and organelles.
Symptoms of viral infections appear late during the disease progression.
Antiviral drugs are mainly virustatic and can also be used prophylactically.

Treatment of Respiratory Viral Infections

Key viruses involved include Influenza A, Influenza B, and Respiratory Syncytial Virus (RSV).
Preferred approach for treatment is immunization; antiviral drugs are alternatives for allergies or during outbreaks.
Influenza A is known for causing pandemics, with notable subtype H1N1.
Surface proteins of Influenza A, hemagglutinin (H) aids in attachment, while neuraminidase (N) facilitates release of new virions.

Neuraminidase Inhibitors

Primary examples include Oseltamivir (oral) and Zanamivir (inhaled).
Effective against both Influenza A and B.
Best when administered prior to exposure or within 48 hours of onset of symptoms, typically for a 5-day course.
Mechanism of action involves inhibition of neuraminidase, preventing new virion release.
Pharmacokinetics: Oseltamivir is a prodrug activated by hepatic esterases; Zanamivir is active upon inhalation.
Excretion for both occurs via urine.
Common adverse effects: Oseltamivir can cause nausea and vomiting; Zanamivir may lead to respiratory discomfort and requires caution in patients with airway diseases.
Resistance may develop through mutations in the neuraminidase enzyme.

Adamantane Antivirals

Includes Amantadine and Rimantadine, with actions limited to Influenza A.
Administered before exposure or within 48 hours of symptoms.
Mechanism of action blocks the M2 proton ion channel, hindering viral uncoating.
Pharmacokinetics differ: Amantadine is excreted unchanged in urine, while Rimantadine undergoes extensive metabolism prior to excretion.
Not recommended due to high resistance rates.

Ribavirin

A guanosine analogue recognized for its broad-spectrum antiviral activity.
Particularly effective against RSV and Hepatitis C virus (HCV) when used with other drugs.
Indicated for severe RSV bronchiolitis or pneumonia in children and infants.
Mechanism of action disrupts replication of RNA and DNA viruses, impacting mRNA synthesis and RNA polymerase activity.
Administered orally or via aerosolized form for RSV, with renal excretion.
Notable adverse effects include dose-dependent anemia and irritation from aerosol use.
Contraindicated in pregnant individuals or those planning to conceive for 6 months post-exposure.

Treatment of Hepatic Viral Infections

Hepatitis viruses include A, B, C, D, and E, with chronic infections primarily caused by HBV (DNA virus) and HCV (RNA virus).
Treatment goals for HBV aim to suppress viral DNA, achieve seroconversion of HBeAg, and lower hepatic transaminase levels.
HCV treatment focuses on viral eradication.

Description

This quiz covers the fundamentals of antiviral drugs, their role as virustatic agents, and their use in the treatment and prophylaxis of viral infections. Explore the characteristics of viruses and the specific treatments for respiratory viral infections.