Antiretrovirals

Question 1

What are the Nucleoside Reverse Transcriptase Inhibitors (NRTI)?

Answer 1

MOA: Nucleoside analogue, phosphorylated and chain termination, target reverse transcriptase.

Abacavir
Lamivudine
Tenofovir Disoproxil Fumarate
Tenofovir alafenamide
Emtricitabine - fluoronated lamivudine (longer half life)

Question 2

What are the Non-nucleoside Reverse Transcriptase Inhibitors (NNRTI)?

Answer 2

MOA: non competitive inhibition of Reverse Transcriptase, No required Phosph, not active against HIV-2, single pt mutation means big resistance

Efavirenz
Rilpivirine

Question 3

What are the Protease Inhibitors?

end in -navir

Answer 3

MOA: target HIV protease, mimics peptide and gets stuck and inactivates

Darunavir
Ritonavir - booster of half life of other ARV
Atazanavir

Question 4

What are the Integrase Strand Transfer Inhibitors (INSTI)?

end in -gravir

Answer 4

MOA: Prevent integration of Viral DNA into genome of host

Raltegravir
Elvitegravir
Dolutegravir

Question 5

What is the Fusion Inhibitor?

Answer 5

MOA: Inhibits fusion protein (GP41)

Enfuviritide: 2x daily injection

Question 6

What is the Co-receptor Antagonist?

Answer 6

MOA: acts at attachment stage (when the virus initially binds and finds a co receptor, this blocks the CCR5 co receptor from bindnig GP120)

Maraviroc: screen for tropism to ensure that the patient has CCR5 receptor activity to be blocked

Question 7

What is the route of administration for each of the antiretroviral drugs?

Answer 7

All are oral EXCEPT Enfuvirtide

which is administered in 2x daily subq injections

Question 8

Which antiretroviral drugs alter the activity of the Cytochrome P450 enzymes?

Answer 8

Ritonavir - Inhibit CYP3A4, 2D6, P450 - large increase in drugs metabolized by these - Used as a BOOSTER
Atazanavir - Inhibit CYP3A4, CYP2C9, P450
Efavirenz - Induces CYP3A4, P450, not bolded

Question 9

What are the extra screening tests used prior to prescribing Abacavir and Maraviroc?

Answer 9

Abacavir: HLA testing for HLA-B5707- prevent hypersensitivity reactions

Maraviroc: Tropism testing to ensure a CCR5 tropism

Question 10

How do Emtricitabine and Lamivudine differ?

Answer 10

Emtricitabine is Fluoronated Lamivudine which gives it a longer half life

Question 11

What antiretroviral drugs are reserved for patients who have not responded to initial treatments?

Answer 11

CCR5 Receptor Antagonist: Maraviroc

Fusion Inhibitor: Enfuvirtide