The document discusses antiviral drugs used to treat herpes virus infections. It lists anti-herpes virus drugs including acyclovir, valacyclovir, famciclovir, ganciclovir, and cidofovir. Acyclovir is the prototypic drug and is active against herpes simplex virus types 1 and 2, varicella zoster virus, and Epstein-Barr virus. It works by inhibiting viral DNA synthesis. Acyclovir is administered orally, intravenously, or topically and is used to treat genital herpes, herpes keratitis, and herpes zoster. Valacyclovir and famciclovir are prodr
2. Learning Outcomes
• 1.7.1 Anti-Herpes Virus
At the end of this session, the student would be able to
discuss the:
– list drugs used for the management of herpes virus infection. (CLO1)
– describe the mechanism of action, pharmacological actions,
pharmacokinetic features, therapeutic uses, adverse effects,
interaction and contraindications of Anti-Herpes virus drugs. (CLO1)
3. Antiviral Drugs
• Viruses are obligate intracellular parasites. They lack both
a cell wall and a cell membrane, and they do not carry
out metabolic processes.
• Viruses use much of the host’s metabolic machinery, and
few drugs are selective enough to prevent viral
replication without injury to the infected host cells.
6. Anti-Herpes Virus
Herpes simplex virus 1 and 2 (HSV-1 and
HSV-2), it is one of the most common
sexually transmitted infections.
Herpes Simplex Virus Structure
Genital Herpes
7. Anti-Herpes Virus
• At the end of this session, the student would be able
to:
– list drugs used for the management of herpes virus
infection. (CLO1)
– describe the mechanism of action, pharmacological
actions, pharmacokinetic features, therapeutic uses,
adverse effects, interaction and contraindications of Anti-
Herpes virus drugs. (CLO1)
10. Anti-Herpes Virus
• Acyclovir :
• Acyclovir is the prototypic antiherpetic therapeutic
agent.
• Acyclovir is active only against herpes group of viruses;
Herpes simplex virus-1 is most sensitive followed by
Herpes simplex virus-2 > varicella-zoster virus =
Epstein–Barr virus, while Cytomegalovirus is practically
not affected.
12. Anti-Herpes Virus
• Pharmacokinetics: Acyclovir is administered by
intravenous (IV), oral, or topical routes. The drug
distributes well throughout the body, including the
cerebrospinal fluid (CSF). Acyclovir is partially
metabolized to an inactive product. Excretion into the
urine occurs both by glomerular filtration and tubular
secretion.
13. Anti-Herpes Virus
• Use of acyclovir:
• Genital Herpes simplex (caused by type-2 virus)
• Mucocutaneous H. simplex (caused by type-1 virus)
• H. simplex encephalitis (type-1 virus)
• H. simplex (type I) keratitis
• H. simplex (type I) keratitis
• Herpes zoster
• Chickenpox
14. Anti-Herpes Virus
• Valacyclovir: The valyl ester, valacyclovir, has greater
oral bioavailability than acyclovir. it is the drug of
choice in herpes zoster.
• Famciclovir: It is an ester prodrug of a guanine
nucleoside analogue penciclovir (the active
metabolite of famciclovir). Famciclovir inhibits H.
simplex, H. zoster but not acyclovir-resistant strains.