Pharm - Anti-virals

Question 0

NRTIs

Answer 0

Competitively inhibit nucleotide binding to reverse transcriptase and terminate the DNA chain.

Remember: Abe tended starving lambs; zed died empty in PA’s BARN

Tenofovir is a nucleoTide, the others are nucleosides and need to be phosphorylated to be active.

Abacavir
Didanosine 
Emtricitabine
Lamivudine
Stavudine
Tenofovir
Zidovudine

Pancreatitis (didanosine)
Anemia (zidovudine)
Bone marrow suppression
Acidosis
Rash
Neuropathy

Question 1

Atazanavir

Answer 1

A protease inhibitor.

Assembly of virions depends on HIV-1 protease (pol gene) which cleaves the polypeptide products of HIV mRNA Into their functional parts. Protease inhibitors prevent maturation of new viruses.

All protease inhibitors end in navir.

Side effects: hyperglycemia, GI intolerance, nephropathy, hematuria (indinavir).

Question 2

Nnrtis

Answer 2

Efavirenz
Nevirapine
Delavirdine

END

Bind to reverse transcriptase at site different from NRTIs. Do not require phosphorylation to be active or compete with nucleotides.

Rash and hepatotoxicity are side effects. Vivid dreams and cns symptoms are common with efavirenz (remember, when you have a fever you have vivid dreams!). Delavirdine and efavirenz are contraindicated in pregnancy.

Question 3

Raltegravir

Answer 3

Inhibits HIV genome integration into host cell chromosome by reversibly inhibiting HIV integrase

Hypercholesterolemia

Question 4

Enfuvirtide

Answer 4

Binds gp41 and inhibits viral entry

Question 5

Maraviroc

Answer 5

Binds ccr5 on the surface of t cells and monocytes, inhibiting interaction with gp120

Question 6

Cidofovir

Answer 6

Preferentially inhibits viral DNA polymase, does not require phosphorylation by viral kinase. Use for cmv retinitis in immunocompromised patients or acyclovir resistant HSV. long half life.

Question 7

Foscarnet

Answer 7

Viral DNA polymerase inhibitor that binds to the pyrophosphate binding site of the ensyme. Does not require activation by viral kinase.

Foscarnet - pyrofosphate analog.

Cmv retinitis in immune compromised patients when ganciclovir fails, acyclovir resistnat hsv.

Question 8

Gancyclovir

Answer 8

5’ monophosphate formed by a cmv viral kinase. Guanosine analog. Triphosphate formed by cellular kinass. Peferentially inhibits viral dna polymerases. Use for cmv.

Question 9

Acyclovir

Answer 9

Monophosphorylated by hsv/vzv thymidine kinase and not phosphorylated in uninfected cells - few adverse effects. Guanosine analog. Preferentially inhibits viral dna pol by chain termination.

Question 10

Ribavarin

Answer 10

Inhibits synthesis of guanine nucleotides by competitively inhibiting inosine monophosphate dehydrogenase

Use for rsv, chronic hep c

Leads to hemolytic anemia, severe teratogen

Question 11

Zanamivir

Answer 11

Inhibits influenza neuranimidase and decreases release of viral progeny