Antivirals

• Classification of drugs


  • Antiviral drugs
  • Antiretroviral drugs
• Antiviral drugs


  Used to treat infections caused by viruses other than HIV
• Antiretroviral drugs


  Used to treat infections caused by HIV, the virus that causes AIDS
• Viruses controlled by antiviral therapy

  • Cytomegalovirus (CMV)
  • Hepatitis viruses (A, B, C)
  • Herpes viruses (HSV-1, HSV-2)
  • Human immunodeficiency virus (HIV)
  • Influenza viruses
  • Respiratory syncytial virus (RSV)
  • Varicella zoster virus (Chickenpox, Shingles)
• Antiviral Drugs


  • Inhibit viral replication
  • Used to treat non-HIV viral infections
• Non-HIV viral infections treated by antiviral drugs

  • Influenza viruses
  • HSV (herpes simplex virus)
  • VZV (varicella zoster virus)
  • CMV (cytomegalovirus)
  • Hepatitis A, B, C (HAV, HBV, NCV)
• Adverse Effects of antiviral drugs

  Vary with each drug<|>Healthy cells are often killed also, resulting in serious toxicities
• Amantadine


  • Narrow antiviral spectrum−active only against influenza A
  • Used prophylactically when vaccine is not available or cannot be given
  • Therapeutic use can reduce recovery time
  • CNS effects: insomnia, nervousness, lightheadedness
  • GI effects: anorexia, nausea, others
• Rimantadine


  • Same spectrum of activity, mechanism of action, and indications as amantadine
  • Fewer CNS adverse effects
  • Causes GI upset
• Acyclovir


  • Synthetic nucleoside analog
  • Used to suppress replication of HSV-1, HSV-2, VZV
  • Drug of choice for treatment of initial and recurrent episodes of these infections
  • Oral, topical, parenteral forms
• Ganciclovir


  • Synthetic nucleoside analog
  • Used to treat infection with cytomegalovirus (CMV)
  • Oral, parenteral forms
  • CMV retinitis: ophthalmic form surgically implanted, ocular injection (fomivirsen)
• Dose-Limiting Toxicities


  • ganciclovir
  • zidovudine
• Dose-Limiting Toxicities


  Bone marrow toxicity
• Neuraminidase Inhibitors


  • Oseltamivir and zanamivir
  • Active against influenza types A & B
  • Use: Reduce duration of illness
• Oseltamivir


  • Causes nausea & vomiting
• Zanamivir


  • Causes diarrhea, nausea, sinusitis
• Treatment should begin within 2 days of influenza symptom onset