Ribavirin

Question 1

What are the two main types of infection that ribavirin treats?

Answer 1

Hepatitis C and human respiratory syncytial virus

Question 2

What type of virus is Hep C?

Answer 2

Positive sense RNA virus

Question 3

How much more effective is treatment with ribavirin?

Answer 3

Just interferon = 29%
With ribavirin as well = 56%
Interferon is a cytokine so also has harsh side effects

Question 4

What type of virus is HSV?

Answer 4

Negative strand paramyxovirus
All humans infected by the age of 2
Symptoms are that of a general cold

Question 5

How do ribavirin work?

Answer 5

Three potential mechanism:

1) inhibition of inosine monophosphate dehydrogenase
2) error catastrophe by nucleotide mis-incorporation by the RdRp
3) inhibition of RNA polymerase via the RdRp

Question 6

What is inosine monophosphate dehydrogenase used for?

Answer 6

Maintaining GTP pools
GTP is required for RNA synthesis
Converts inosine MP into xanthosine MP
XMP goes to GTP

Question 7

What does ribavirin do to increase the amount of mutations in RdRp?

Answer 7

Increases the amount of mutations to 7 per genome

Nearly all mutations are in place of G or A nucleotides and ribavirin can base pair with C or U

Question 8

What does ribavirin do with RNA?

Answer 8

Minims an rNTP as it can fit into the RNA polymerase active site

Question 9

What side effects are there with ribavirin?

Answer 9

General cytotoxicity and haemolytic anaemia

Stored in RBA for about 6 weeks

Question 10

What is ribavirin?

Answer 10

Guanosine analogue
Incomplete purine ring
Pro-drug (aerosol or tablet)
Active against both RNA and DNA viruses