5/29- HIV Treatment Flashcards

(43 cards)

1
Q

What are the different cellular targets of HIV?

A
  • CCR5
  • CXCR
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2
Q

HIV drug targets?

A

Entry inhibitors

  • CCR5 antagonists
  • Fusion inhibitors RT inhibitors

Nucleoside analogs (NRTI)

Non-nucleoside analogs (NNRTI)

Integrase inhibitors (preventing incorporation of genetic material)

Protease inhibitors (prevent assembly/budding release of virus)

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3
Q

Name the CCR5 antagonist(s)

A

Maraviroc

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4
Q

Name the fusion inhibitor(s)

A

Enfuvirtide

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5
Q

Name the NRTI(s)

A
  • Abacavir
  • Lamivudine
  • Emtricitabine
  • Tenofovir
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6
Q

Name the NNFRTI(s)? Recongize, don’t memorize

A
  • Efavirenz
  • Etravirine
  • Rilpivirine
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7
Q

Name the integrase inhibitor(s)? Recognize, don’t memorize

A
  • Dolutegravir
  • Elvitegravir
  • Raltegravir
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8
Q

Name the protease inhibitor(s)? (PIs) Recognize, don’t memorize

A
  • Atazanavir
  • Darunavir
  • Lopinavir/rit
  • Fosamprenavir
  • Indinavir
  • Nelfinavir
  • Saquinavir
  • Tipranavir
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9
Q

Name the pharmokinetic booster(s)?

A
  • Ritonavir (a PI)
  • Cobistat

No antiviral activity

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10
Q

Overview chart of HIV drugs

A
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11
Q

How often most antiretrovirals be taken?

A
  • Initially every 8 hours on the dot (?)
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12
Q

How to decrease crests/troughs antiretroviral?

A

Give with pharmokinetic booster

e.g. Indinavir with ritonavir (trough levels 10x higher)

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13
Q

Drugs with the same mechanism of action share what features?

A
  • Elimination/metabolic pathways
  • Toxicities/side effects
  • Mechanisms of resistance (cross-resistance)
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14
Q

Goals of HIV treatment?

A
  • Maximally/durably suppress HIV viral load (undetectable < 20 RNA copies/mL)
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15
Q

How many weeks of therapy does it take to get viral load below detectable levels (< 20 RNA copies/mL)

A

~ 9 weeks

(although huge drop by just 2 weeks)

Also, takes longer if you start with a higher viral load (up to 6 mo)

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16
Q

Which class of drugs has relatively less cross-resistance?

A

Protease inhibitors

(also, takes many mutations to render these inactive)

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17
Q

What factor contributes to the greatest CD4 cell count increase? (immune reconstitution)

A

Therapy started at low CD4 counts

(greater rise and prolonged, but less likely to normalize)

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18
Q

What factor contributes to the greatest likelihood of CD4 cell count normalization? (immune reconstitution)

A

Therapy started earlier, with higher CD4 counts

19
Q

For whom is antiretroviral treatment especially recommended?

A
  • All HIV infected pregnant women (prevent perinatal transmission)
  • All at risk of transmitting HIV to sex partners
  • HIV infected drug users
20
Q

Risks of treatment complications and treatment failure due to?

A

Emergence of resistance

21
Q

Strength of recommendation for treatment?

A

(A-strong, B- moderate, C- optional)

(I- trials, II- good trials/cohort studies, III- expert opinion)

Based on CD4 count

AI: < 350

AII: 350-500

BIII: > 500 (can wait to start until certain other issues are resolved)

Based on condition:

AI: pregnant, AIDS defining condition, infected heterosexual partner

AII: HIV-associated nephropathy, Hep B co-infection

AIII: other transmission risk groups, rapidly declining CD4 count (>100 cells/year)

BII: higher viral loads

22
Q

Recommended antiretroviral regimes?

A

2 NRTIs (backbone)

  • Emtricitabine-Tenofovir (Truvada) or
  • Abacavir-Lamivudine (Epzicom)

AND either:

- Boosted PI based: Darunavir + Ritonavir or

- Integrase inhibitor: Raltegravir, Dolutegravir, or Elitegravir/coicistat

23
Q

Abacavir given only to whom?

A

Pts that tested negative for HLA B*5701

24
Q

Recommended alternative antiretroviral regimes?

A

Boosted PI based:

  • Emtricitabine/Tenofovir

AND one of:

  • Atazanavir + Ritonavir
  • Atazanavir/cobicistat
  • Darunavir/cobicistat

NNRTI-based:

  • Efavirenz/emtricitabine/tenofovir
  • Rilpivirine/emtricitabine/tenofovir
25
What factors determine combination of therapy?
- Virus susceptibility (test at BASELINE) - Patient's profile (underlying comborbidities, or ASEs to avoid) - Patient's preference - Potential for drug interactions - Cost
26
Treatment related complications?
Metabolic: - **Insulin resistance** - **Dyslipidemia** Cardiovascular: **increased MI** Bone: **osteoporosis** Renal: **renal insufficiency**
27
What is lipodystrophy?
Body Habitus Changes - Fat deposition (intrabdominal, dorsocervical, breasts) - Fat atrophy (extremity wasting, facial lipoatrophy, mostly D4T, ddI and AZT)
28
Management of HIV-infected pt on treatment at each visit?
- Clinical psycho/social evaluation - Adherence to treatment; side effects - Counseling on prevention of transmission - Primary care interventions
29
Lab evaluation for management of HIV infected pt on treatment?
General labs (to assess toxicities) Response to treatment: - CD4 cell count (immunologic response) - HIV1 viral load (virologic response) **\*\*most important**
30
HIV-1 viral load should be measured at what frequencies at different stages?
- every 2-4 wks after start of treatment - every 3-4 months until viral load suppressed - every 4-6 months after 2 yrs of continous suppression
31
CD4 cell count should be measured at what frequencies at different stages?
- every 3-4 months - every 6-12 months for those with continuous suppression and high CD4 cell count
32
Virologic failure caused by what?
Caused by: - Virologic suppression - Incomplete virologic response - Virologic rebound
33
Virologic suppression characterized how?
Viral load **below level of detection** (\< 20 RNA copies/mL) at **week 24** of treatment
34
Incomplete virologic response is characterized how? Due to what?
Consecutive **VL \> 200 after 24 wks** of treatment Due to: - inadequate potency - Inadequate drug levels - Inadequate adherence (mot common) - Pre-existing resistance
35
Virologic rebound is characterized how?
**VL \> 200 after suppression** to non-detectable levels (More than 2 subsequent increases in viral load following previous undetectable VL)
36
What causes in-vivo viral drug resistance?
**Poor adherence** - Social/personal issues - Regimen issues - Toxicities **Insufficient drug level** - Poor adherence - Poor potency - Wrong dose - Host genetics - Drug interactions - Poor activation Leads to: **- Viral replication in the presence of the drug** **- Resistant virus**
37
Management of virologic failure?
- Assess adherence to treatment - Assess tolerability - Assess for drug/food interactions - Obtain resistance testing (requires VL \> 1000 RNA copies/mL; while pt is on failing therapy or within 4 wks)
38
Resistance testing for phenotype entails what?
**Culturing** the virus in the presence of different concentrations of the drug and determining the **IC50** (drug conc required to inhibit viral replication by 50%)
39
Resistance testing for genotype detects what?
Mutations associated with viral resistance
40
Management of HIV-infected pt with resistant virus?
- Reassess barriers to adherence - Select new antiretroviral combination (must include at least 2 drugs and preferable 3 to which the virus is expected to be susceptible) - Goal is to maximally suppress viral replication to below level of detection
41
Case 1: - HIV infected patient, new to your clinic, never treated, asymptomatic. He is starting a new relationship with a non-HIV infected partner - Has a CD4 cell count (CD4) of 500 and viral load of 10,000 - What parameter would be the most important in the decision to start treatment in this patient? A. Symptoms B. CD4 cell count C. HIV-1 viral load D. Risk for transmission
Case 1: - HIV infected patient, new to your clinic, never treated, asymptomatic. He is starting a new relationship with a non-HIV infected partner - Has a CD4 cell count (CD4) of 500 and viral load of 10,000 - What parameter would be the most important in the decision to start treatment in this patient? A. Symptoms B. CD4 cell count C. HIV-1 viral load **D. Risk for transmission**
42
Case 1 cont'd: Patient is started on a regimen that includes one integrase inhibitor and 2 nucleoside analogues. - At 3 months his VL is \< 50 - At 6 months his VL is 190 and CD4 count is the same at 500. What would you do next? A. Order genotype B. Repeat CD4 count C. Repeat viral load D. Change treatment
Case 1 cont'd: Patient is started on a regimen that includes one integrase inhibitor and 2 nucleoside analogues. - At 3 months his VL is \< 50 - At 6 months his VL is 190 and CD4 count is the same at 500. What would you do next? A. Order genotype B. Repeat CD4 count **C. Repeat viral load** D. Change treatment
43
Summary: Key prevention of HIV: Goal of treatment: Means of achieving goal of treatment:
Summary: Key prevention of HIV: **test for HIV and treat** Goal of treatment: **complete viral suppression** Means of achieving goal of treatment: **potent ARV combination and adherence to treatment**