Lecture on Acyclovir

Overview

• Acyclovir is an antiviral drug
• Inhibits viral DNA synthesis
• Specifically targets infected cells

Mechanism of Action

• Viral DNA synthesis in infected cells uses DNA building blocks (adenosine, guanosine, etc.)
• Acyclovir mimics guanosine but is defective
  • Results in defective viral DNA when incorporated
• Does not inhibit DNA synthesis in healthy cells
  • Not a chemotherapy agent
  • Requires activation by the enzyme thymidine kinase (only present in infected cells)

Uses

• Targeted against herpesviruses Types 1, 2, and 3
  • Herpes simplex viruses (Types 1 & 2)
  • Varicella virus (Type 3)
• Can also be used for herpes Type 4 (Epstein-Barr virus) at high concentrations
• Most effective when used at the onset of symptoms

Side Effects

• Can crystallize in kidneys and cause renal damage
  • Especially when administered intravenously (IV)
• Resistance can develop in viruses
  • Through mutation in thymidine kinase enzyme
  • Especially noted in HIV patients

Quiz

• How to minimize renal damage associated with acyclovir use?
  • Answer provided in lecture.

Conclusion

• Recap of key points about acyclovir
• Importance of timing and monitoring for resistance and renal side effects.