3. Antivirals available for many viral infections
Viruses controlled by current antiviral therapy
• Cytomegalovirus (CMV)
• Hepatitis viruses
• Herpes viruses
• Human immunodeficiency virus (HIV)
• Influenza viruses (the “flu”)
• Respiratory syncytial virus (RSV)
4. • Retrovirus: Subdivision of viruses,
includes HIV
Antiviral Key Terms
• Mutable – the mutation of a single nucleotide is sufficient to
render drug ineffective
• Prodrug: A drug that is converted in the body to the
active drug
• Nucleoside: A building block of DNA/RNA
5. Antiviral Drugs
• Prevent viruses from reproducing
• Block viral entry into cell – must
work inside of cell
• Most agents are pyrimidine or purine
nucleoside analogs
• 2 major types
• Retrovirus
• Non-retrovirus
7. Anti-herpesvirus Agents “-cyclovir”
• Nucleoside Analogues
• Fool virus into using them instead of nucleoside to construct RNA/DNA.
• Halt construction d/t lack of 3’ hydroxyl group
• Acyclovir:
• inibitory activity against herpes simplex virus types 1 (HSV-1), 2 (HSV-2), and
varicella-zoster virus (VZV).
• Ganciclovir, Penciclovir:
• inhibits viral DNA synthesis
• Valaciclovir:
• Prodrug of acyclovir
8. Anti-influenza Agents “-tadine, -mivir”
• Amantadine, (Symmetrel) Rimantadine
• Inhibit protein in early stage of replication (Influenza A)
• Tx: sx of Parkinson’s disease
• Zanamivir, (Relenza) Oseltimivir (Tamiflu)
• Inhibits neuraminidases (Influenza A + B)
• with milk protein allergy
• Ribavirin
• (ART) – Antiretroviral therapy:
• serious life-threatening flu ONLY
10. Classifications of Antivirals
•Antiretroviral Agents
Developed for treatment of HIV
*5 types*
• NRTIs - Nucleoside reverse transcriptase inhibitors
• NNRTIs – Non-nucleoside reverse transcriptase inhibitors
• Protease inhibitors
• Entry inhibitors/fusion inhibitors
• Integrase strand transfer inhibitors
11. Nucleoside reverse transcriptase inhibitors (NRTIs)
• NRTIs, sometimes called "nucleoside analogues" or "nukes," contain
faulty versions of the building blocks (nucleotides) used by reverse
transcriptase to convert RNA to DNA.
• When reverse transcriptase uses these faulty building blocks, the new
DNA cannot be built correctly.
• In turn, HIV's genetic material cannot be incorporated into the
healthy genetic material of the cell and prevents the cell from
producing new virus.
12. NRTIs “-vudine”
Prevents protein synthesis in the retroviral cell, which in turn stops
reproduction.
• Abacavir, didanosine
• Transient risk cardiovascular events
• Stavudine, zidovudine
• lipid levels, glucose tolerance
• Prolonged exposure linked to:
• Non-cirrhotic portal hypertension
• Esophageal varices
• Serious potential risk: Lactic acidosis
• Females/Obese
• Mortality = 50%
Nucleoside
Analog (NRTI)
13. Non-nucleoside reverse transcriptase inhibitors (NNRTIs)
“-virine, -virdine”
• NNRTIs are antiretroviral drugs used in the treatment of HIV.
• Inhibit reverse transcriptase (RT)
• enzyme that controls the replication of HIV genetic material.
• Reduces ability of enzyme to perform its function
• May cause liver damage
19. Antiparasitic Agents “-quine”
Individuals with Susceptibility to parasites:
• Pregnant women
• People with HIV/AIDS
• Antimalarials: work against Plasmodium
• Quinine: Preg. Code X
• Chloroquine: cross-reacts w/antacids/laxatives
• Mefloquine: risk of cardiac arrhythmias
• Metronidazole (Flagyl) antiprotozoal/antibiotic
