Anti-virals

Question 1

What is the mechanism of action of acyclovir?

Answer 1

Acyclovir is a acyclic guanine nucleoside analogue that once phosphorylated, stops replication of viral DNA in 3 ways:

1. Competitively inhibits viral DNA polymerase
2. Inactivates viral DNA polymerase
3. Is incorporated into the viral DNA chain, preventing the elongation of the viral DNA chain

Question 2

Acyclovir is the synthetic analog of which nucleoside?

Answer 2

Guanine

Question 3

What is the difference between acyclovir and valacyclovir?

Answer 3

Valacyclovir is the prodrug of acyclovir; it has much better oral bioavailability

Question 4

What is acyclovir indicated in?

Answer 4

HSV1, HSV2, VZV & EBV

Question 5

Acyclovir & valacyclovir is contraindicated in which group of individuals?

Answer 5

Patients with renal impairment

Question 6

What is the mechanism of action of ganciclovir?

Answer 6

Ganciclovir is a acyclic guanine nucleoside analogue that once phosphorylated, stops replication of viral DNA in 3 ways:

1. Preferentially inhibits viral DNA polymerase
2. Inactivates viral DNA polymerase
3. Is incorporated into the viral DNA chain, preventing the elongation of the viral DNA chain

Question 7

What is ganciclovir indicated in?

Answer 7

All herpesviruses especially CMV

Question 8

How is ganciclovir administered?

Answer 8

IV; prodrug valganciclovir has better oral bioavailability

Question 9

How is acyclovir administered?

Answer 9

PO/IV/topical

Question 10

What is the main adverse effect of acyclovir?

Answer 10

Nephrotoxicity