HIV – MOA

The correct answer is Entecavir is intracellularly phosphorylated to guanosine triphosphate which competes with natural substrates to effectively inhibit hepatitis B viral polymerase; enzyme inhibition blocks reverse transcriptase activity thereby reducing viral DNA synthesis.

The correct answer is Raltegravir inhibits the catalytic activity of integrase, thus preventing integration of the proviral gene into human DNA.

The correct answer is Oseltamivir, a prodrug, is hydrolyzed to the active form, oseltamivir carboxylate (OC). OC inhibits influenza virus neuraminidase, an enzyme known to cleave the budding viral progeny from its cellular envelope attachment point (neuraminic acid) just prior to release.

The correct answer is Maraviroc, a CCR5 antagonist, selectively and reversibly binds to the chemokine (C-C motif receptor 5 [CCR5]) coreceptors located on human CD4 cells. CCR5 antagonism prevents interaction between the human CCR5 coreceptor and the gp120 subunit of the viral envelope glycoprotein, thereby inhibiting gp120 conformational change required for CCR5-tropic HIV-1 fusion with the CD4 cell and subsequent cell entry.

The correct answer is acyclovir is converted to acyclovir monophosphate by virus-specific thymidine kinase then further converted to acyclovir triphosphate by other cellular enzymes. Acyclovir triphosphate inhibits DNA synthesis and viral replication by competing with deoxyguanosine triphosphate for viral DNA polymerase and being incorporated into viral DNA.

The correct answer is it binds to the site of HIV-1 protease activity and inhibits cleavage of viral Gag-Pol polyprotein precursors into individual functional proteins required for infectious HIV. This results in the formation of immature, noninfectious viral particles.

The correct answer is it is rapidly and almost completely converted to amprenavir by cellular phosphatases in vivo. Amprenavir binds to the site of HIV-1 protease activity and inhibits cleavage of viral Gag-Pol polyprotein precursors into individual functional proteins required for infectious HIV. This results in the formation of immature, noninfectious viral particles.

The correct answer is it binds to the site of HIV-1 protease activity and inhibits cleavage of viral Gag-Pol polyprotein precursors into individual functional proteins required for infectious HIV. This results in the formation of immature, noninfectious viral particles.

The correct answer is as a non-nucleoside reverse transcriptase inhibitor, efavirenz has activity against HIV-1 by binding to reverse transcriptase. It consequently blocks the RNA-dependent and DNA-dependent DNA polymerase activities including HIV-1 replication. It does not require intracellular phosphorylation for antiviral activity.

The correct answer is a nucleoside and nucleotide reverse transcriptase inhibitor combination; emtricitabine is a cytidine analogue while tenofovir is an analog of adenosine 5′-monophosphate. Each drug interferes with HIV viral RNA dependent DNA polymerase resulting in inhibition of viral replication.

The correct answer is it rapidly and nearly completely converted to acyclovir by intestinal and hepatic metabolism. Acyclovir is converted to acyclovir monophosphate by virus-specific thymidine kinase then further converted to acyclovir triphosphate by other cellular enzymes. Acyclovir triphosphate inhibits DNA synthesis and viral replication by competing with deoxyguanosine triphosphate for viral DNA polymerase and being incorporated into viral DNA.