microbiology viral

Question 1

nucleoside analogs how do they work?

Answer 1

activated by viral kinases and selectivity occurs as the drug can bind better to viral rather than cellular dna polymerases

Question 2

what nucleoside analogs do you know? mention first 4!
acy and gangci
cido and ade azido

Answer 2

1) acyclovir- selective against hsv and vzv, minimal toxicity. other modified versions are valacyclovir (better absorbtion) etc.
2) gangciclovir- works against cmv. also used in tumor therapy (injected with retrovirus and has toxicity).
3) cidofovir+ adefovir- substrates for dna polymerase or reverse transcriptase.
4) azidothymidine- used in hiv treatment- prevention of progression. large side-affectes- bone marrow toxicity and nausea.

Question 3

mention last 4 nucleoside analogues

Answer 3

5) dideoxyinosine/ didioxycytidine, stuvudine/ lamivudine- all used for hiv, inhibit hiv transcriptase.
6) ribarvirin- given to children with respiratory syncytial virus bronchopneumonia and to adults with influenza or measles.
7) idoxuridine/ fluorouracil/ idoxuridine- analogs of thymidine and incorporate into the dna. causes misreading of the genome and leads to mutation and inactivation of the virus.
8) adeninine arabinoside- anti hcv drug.

Question 4

non-nucleoside polymerase inhibitors-

Answer 4

foscarnet (FPA)- viral replication inhibitor.

nevirapine.

Question 5

protease inhibitors

Answer 5

squinavir