Fitz, HIV Anti-Virals Flashcards Preview

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Flashcards in Fitz, HIV Anti-Virals Deck (52)
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1
Q

Three main viral processes that are targeted by the drug combos used in INITIAL therapy.

A
  1. HIV reverse transcriptase
  2. HIV integrase
  3. HIV protease
2
Q

What are the two reservoirs that HIV can reside?

Which 2 NRTIs and 1NNRTIs can get into the brain?

A
  • Reservoir - GALT and spinal cord/brain.
    NRTI - AZT, d4T
    NNRTI - nevirapine
3
Q

Name the three NRTIs that are Purines.

A

Abacavir
Didanosine
Tenofovir

4
Q

Name the four NRTIs that are Pyrimidines

A

Lamivudine
Emtricitabine
Zudovudine
Stavudine

5
Q

What must host cells do to the ingested NRTI?

A

Host enzymes must metabolize the prodrug into a NucleoTide Triphosphate&raquo_space; Emtricitabine(FTC)-analog in the cell!

6
Q

What does the NRTI-Triphosphate do inside CD4 cells harboring replicating HIV?

A

Emtricitabine(FTC)-TPs are incorporated into the viral DNA by viral DNA polymerase and then —> terminate viral DNA synthesis.

7
Q

How do NRTI-TPs terminate viral DNA synthesis?

A

Because they lack a 3’ hydroxyl group.

8
Q

How many NRTIs are given to all HIV patients?

A

Two

9
Q

N/V/abdominal pain, weight loss, myalgia, geatures of HEPATIC DYSFUNCTION, HM, peripheral edema, ascites, encephalopathy.

These show what?

A

LACTIC ACIDOSIS

Black box warning of all NRTIs. Potentially fatal.

10
Q

Why do all NRTIs have the potential for lactic acidosis?

A

Because they DNA reverse transcriptase AND they inhibit mt-DNA-polymerase-gamma

11
Q

How does inhibition of mt-DNA-polymerase-gamma result in lactic acidosis?

A

Inhibition of mt-DNA-polymerase-gamma —> deficient proteins needed for OxPhos, so inhibits aerobic metabolism and increases ANAEROBIC metabolism —> LACTIC ACIDOSIS.

12
Q

The three NRTIs that inhibit mt-DNA formation MOST.

A

Didanosine > Stavudine ≥ Zidovudine

13
Q

The three NRTIs that inhibit mt-DNA formation LEAST.

A

All the first line NRTIs:

Tenofovir = Lamivudine = Emtracitabine = Abacavir

14
Q

All NRTIs have what adverse effect?

A

Disrupt triglyceride metabolism throught the body - morphological/fat deposits.

15
Q

In what three settings should NRTI be suspended?

A
  1. Rapidly rising aminotransferase levels
  2. Progressive HM
  3. Metabolic acidosis of unknown cause
16
Q

Pts with ___ should avoid Tenofovir? Why?

A

Renal insufficiency - Tenofovir is already phosphorylated upon ingestion (nucleoTide) —> RENAL elimination

17
Q

Substitute what for tenofovir?

A

Abacavir

18
Q

A pt is on a NRTI and develops fever, rash, GI, respiratory symptoms, lethargy or malaise. What drug is this person on?

A

Abacavir - this is systemic abacavir hypersensitivity

19
Q

Abacavir can be used safely in what individuals?

A

They are Negative for HLA-B*5701 genotype.

Positive = abacavir hypersensitivity

20
Q

**Preferred NRTI combination.

A

Tenofovir-Emtracitabine

21
Q

NRTI combination for an individual HLA-B(-) and at risk for renal or bone toxicity?.

A

Abacavir-Lamivudine

22
Q

Caution using what NRTI combination for an individual HLA-B(+) and at risk for renal or bone toxicity?

A

Caution use of abacavir in the abacavir-lamivudine combo.

23
Q

NRTI combination for a pregnant individual.

A

Zidovidine-Lamivudine

24
Q

What three NRTIs are active against HepB?

A

Tenofovir
Emtracitabine
Lamivudine

25
Q

MOA of Non-Nucleoside Reverse Transcriptase Inhibitors

A

Bind to reverse transcriptase at site different form NRTIs.

26
Q

How is the activation of Non-Nucleoside Reverse Transcriptase Inhibitors different than NRTIs?

A

Do not require phosphorylation to be active or compete with nucleosides.

27
Q

What NNRTI is avoided in pregnancy?

A

Efavirenz (DOC)

28
Q

What NNRTI is used during pregnancy or if a woman is trying to conceive?

A

Nevirapine (1st line alternative).

29
Q

**What NNRTI is used if resistance to other NNRTIs is developed?

A

Etravirine (1st line alternative).

30
Q

If a woman is on efavirenz and becomes pregnant, what should be done?

A

If viral suppression has been achieved, continue efavirenz-containing regimen.

31
Q

Rash/hypersensitivity - think what class of drugs?

A

All NNRTIs

32
Q

A HIV+ pt is taking a NNRTI and develops a skin burn-type reaction. What is this reaction and which drug are they most likely taking?

A

Stevens-Johnson

think Nevirapine.

33
Q

Why do you start a TB+ and HIV+ pt on TB tx-regiment first?

A
  • Because the NNRTIs have a -life-threatening hepatotoxicity (nevirapine).
  • Because NNRTIs induce CYP450 (efavirenz)
34
Q

K103N mutation - associate with what?

What is the one drug exception that can be used?

A

Point mutation in virus that confers drug resistance to NNTRIs.
-Etravirine

35
Q

Preferred combo of NTRIs and NNTRI (not pregnant)

Other than HIV, what else does it treat?

A

NTRI - Tenofovir+Emtracitabine
NNTRI - Efavirenz

Also treats HepB

36
Q

Preferred combo of NTRIs and NNTRI (pregnant)

A

NTRI - Zedovidine-Lamivudine (Lamivudine=HepB)

NNTRI - Nevirapine

37
Q

MOA of Protease inhibitors

A

PIs prevent maturation of new viruses because it inhibits the HIV-1 protease (pol gene), which normally cleaves products of HIV mRNA into functional parts.

38
Q

**Significance of ritonavir

A

“Boosting” - CYP3A inhibitor

Used with other oral protease inhibitors (atazanavir or lopinavir) to inhibit their hepatic metabolism

39
Q

**MOA of ritonavir’s boosting effects.

A

Decreases the extensive first pass hepatic metabolism of the other Protease Inhibitors - Atazanavir, Lopinavir

40
Q

A HIV+ person (about to start tx regimen) has PCP pneumonia and tx with TMP-SMX. They develop a life threatening allergic reaction. What PI is contraindicated?

A

Darunavir and fosamprenavir, and tipranavir are sulfonamides, so should not be given to a person with a sulfonamide allergy (allergy to SMX)

41
Q

Short term adverse effect of Protease Inhibitors.

A

Hepatotoxicity (*atanazavir and PPIs, CYP450 interactions, esp with ritonavir**)

42
Q

Adding PI to the regimen of NRTIs increases what adverse effect?

A

Triples the prevalence of lipodystrophy (compounds already present in NRTIs).

43
Q

Preferred treatment combos (4) for NRTIs + PIs

A
NRTIs - Tenofovir + Emtracitabine
PIs (Preferred):
1.  **Atazanavir+Ritonavir
2.  Darunavir+Ritonavir
PIs (Alternates):
3.  **Lopinavir+Ritonavir**
4.  Fosamprenavir+Ritonavir
44
Q

A person (nonpregnant) gets a needle puncture wound and/or is exposed to blood or semen of a HIV infected individual. What is the appropriate Post-exposure Prophylaxis?

A

Tenofovir + emtricitabine + Lopinavir + Ritonavir

Four weeks, 1x/day

45
Q

A person (pregnant) gets a needle puncture wound and/or is exposed to blood or semen of a HIV infected individual. What is the appropriate Post-exposure Prophylaxis?

A

Zidovudine + Lamivudine + Lopinavir + Ritonavir (Four weeks, 2x/day)

46
Q

Post-exposure Prophylaxis - add what class to NRTIs?

A

Protease Inhibitor

47
Q

Overall Preferred REgimen in HIV+ Women:

A

2 NRTIs + PIs

Zidovudine + Lamivudine + Lopinavir + Ritonavir (2x/day)

48
Q

MOA of Integrase strand transfer Inhibitors (IIs) and name of drug.

A

Raltegravir

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

49
Q

Advantage of using Raltegravir over a protease inhibitor?

A

Does not cause lipid-causing morphologic changes.

50
Q

MOA of fusion inhibitor enfuvirtide.

A

Binds gp41, inhibiting viral entry.

51
Q

MOA of fusion inhibitor maraviroc.

A

Binds CCR-5 on surface of T cells/monocytes, inhibiting interaction with gp120.

52
Q

Which Protease Inhibitor ahs a black box label?

A

Tripranavir - fatal hepatitis and IC hemorrhage.