antivirals mod 2

Question 1

Antivirals:
acyclovir/Zovirax
valcylovir/Valtrex
famciclovir/Famvir

Answer 1

Routes: oral, tablets and liquid, topical cream and ointment, intravenous

MOA: (works in 3 different ways)
Interferes with viral nucleic acid synthesis, its regulation or both (DNA & RNA)

Prevents virus from binding to cells so VIRUS CANNOT GET INTO CELLS thus preventing viral replication

Stimulates the body’s IMMUNE SYSTEM to kill the virus

Question 2

acyclovir (Zovirax)

herpes virus usage

1 above the waist
2 below the waist

Answer 2

Indications:
Used to suppress replication of:
 HSV 1(oral)  
 HSV 2 (genital) 
 VZV (herpes zoster and varicella/chickenpox) 

decrease Symptom severity and frequency of outbreaks, NOT a cure!
Used for BOTH initial and recurrent infection
May require MULTIPLE TREATMENTS!

Reduces viral shedding and decreases local symptoms
decrease severity and duration of illness
Disease can reoccur, again, NOT A CURE
Available po, IV, and topical

SE: GI distress, renal impairment, seizures, ITP
IV form – tissue necrosis if IV not patent

Question 3

oseltamivir/Tamiflu

influenza A some B

Answer 3

MOA: Inhibit neuraminidases in influenza viruses
Indications:

Used for prophylaxis and to treat active disease (48H of sx onset)
Most often given to elderly and immunocompromised after KNOWN EXPOSURE to influenza A and B
CDC approved April 2009 for treatment of H1N1 (swine flu)
Available po only

SE: nausea and vomiting; seizures, renal impairment

Question 4

ganciclovir [Zirgan]

Treats the cytomegalovirus (CMV)
pancytopenia, fertility

Answer 4

CMV - immunocompromised patients (AIDS, immunosuppressed, transplants)
Controls but doesn’t cure

MOA: inhibits viral DNA polymerases resulting in chain termination
IV & PO

Black box warnings: hematologic toxicity, fertility impairment, fetal toxicity, carcinogenesis
Don’t give with imipenem-cilastatin - increase seizure potential

Watch kidneys if given with other nephrotoxic drugs