HIV Flashcards
What is ART?
Antiretroviral therapy
What is AI?
Disease progression
What conditions increase the urgency of initiation of therapy?
Pregnancy AIDS-defining conditions, including HIV-associated dementia Acute opportunistic infectoin Lower CD4 counts HIV-associated nephropathy HIV-HBV co-infection HIV/HCV co-infection Acute/early infection
What are the goals of therapy?
Maximal and durable suppression of VL.
Restoration or preservation of immunologic function.
Improvement of QOL.
Reduction of HIV-related morbidity and mortality; prevention of opportunistic infections.
Avoidance of ADRs.
Prevent transmission.
What factors should be considered before selecting a regimen?
Comorbid conditions Potential ADRs Potential drug interactions with other medications Pregnancy or pregnancy potential Results of genotypic drug resistance testing HLA-B*5701 testing if considering ABC Convenience Financial stability
What is the MOA of NRTIs
Require intracellular phosphorylation of the 5’-triphosphate moiety to be active.
The 5’-triphosphate competes with endogenous deoxynucleotides for reverse transcriptase enzyme and prematurely terminates DNA elongation d/t modified 3’-hydroxyl group.
What is the BBW for NRTIs?
Lactic acidosis
How are NRTIs eliminated?
Renally (no CYP450 interactions or DDIs)
What are some ADRs of NRTIs?
Pancreatitis
Lipodystrophy/lipoastrophy
Which NRTIs have activity against Hep B?
3TC/FTC
TDF/TAF
How often are Combivir and Trizivir taken?
1 tab BID
How often are Epzicom, Truvada, and Descovy taken?
1 QD
What are the thymidine analogue NRTIs?
AZT/ZDV
d4T
Which NRTIs can be taken in pregnancy?
AZT/ZDV
Lamivudine
What are the side effects of 3TC?
None
What are the side effects of FTC?
Well tolerated
Skin hyperpigmentation
What drug should not be combined with d4T?
AZT/ZDV (both thymidine analogues)
ddI (similar toxicities)
What are the ADRs of ABC?
Hypersensitivity (2-9%) - flu like symptoms - happens in the morning - worsens progressively
Which drug do we do an HLA B*5701 test for?
ABC
How is ABC eliminated?
Renally as inactive metabolits
No adjustments needed
What are TDFs ADRs?
N/V
Decreased BMD, renal dysfunction, esp when used in boosted regimens (w/RTV/COBI)
Generally well tolerated
What are TAFs ADRs?
Well tolerated
Better safety profile (renal, bone) compared to TDF
What are NNRTIs MOA?
Bind non-competitively to RT and cause a conformational change.
Do not require intracellular phosphorylation and do not complete w/endogenous deoxynucleotides
How are NNRTIs metabolized?
By CYP450
What is the NNRTI half-life?
Very long
What is a common ADR of all NNRTIs?
Rash
LFT increases
What are the first generation NNRTIs?
EFV
NVP
What are the second generation NNRTIs
ETV
RPV
What are the ADRs for EFV?
Rash (up to 10%) CNS effects Increased LFTs Increased lipids Neural tube defects if given in first 5-6 weeks of gestation. Pregnancy category D
What are the ADRs for NVP?
Do not start in women w/ >250 CD4 or men w/ > 400 d/t hepatotoxicity
How is EFV metabolized?
It is a P-450 substrate and inducer
How is NVP metabolized?
It is a P-450 autoinducer and inducer of other drugs
What are the DDIs of ETV?
Multiple drug interactions
What enzymes are ETV a substrate for?
3A4
2C9
2C19
What enzymes are ETV an inducer for?
3A4
What enzymes are ETV an inhibitor for?
2C9
2C19
What is ETV currently approved for?
Anti-retroviral experienced patients only
What are the ADRs for RPV?
Rash Depression Insominia HA Increased QT interval
Which NNRTI must be taken with a meal?
RPV
Meal must be > 500 cal
Which NNRTI has acid dependent absorption?
RPV
DDI with acid-reducing agents
How does RPV affect CYP enzymes?
It is a substrate
When should RPV NOT be started?
> 100,000 HIV-1 RNA copies
or
< 200 CD4
What is RPV approved for?
Anti-retroviral naive patients only
How should Atripla be taken?
1 QHS
How should Complera and Odefsey be taken?
1 QD
What are the ADRs of COBI?
Acute renal failure and Fanconi syndrome (when used with tenofovir)
What is COBI approved for?
Only to boost atazanavir and darunavir
Is COBI interchangable?
Not with ritonavir for all other PIs
What are the PK enhancers?
COBI
Ritonavir
What are PIs MOAs?
Block the maturation process, thereby resulting in the production of immature, noninfectious virions
How are PIs metabolized?
CYP-450
What are the GI ADRs of PIs
Lipodystrophy Hyperlipidemia Hyperglycemia Pancreatitis LFT increases
Why are PKs used with PIs?
PIs are poorly absorbed
What are the ADRs of RTV?
GI: loose stools, maybe diarrhea 1st couple of weeks then it goes away
How is RTV involved with CYP enzymes?
Very potent CYP450 inhibitor
What are the ADRs of ATV?
GI
Hyperbilirubinemia
Nephrolithiasis
Which PIs have a sulfa moiety?
DNV
FPV
TPV
What are DNVs ADRs?
GI
rash
Which PIs are preferred in pregnancy?
ATV
DNV
How is evotaz taken?
1 QD
How is Prezcobix taken?
1 QD
What is needed in addition to Evotaz and Prezcobix?
Still need 2 other agents
What is the MOA of entry inhibitors?
Inhibit the various steps of HIV with CD4 cells
What is the fusion inhibitor?
T-20
What are the ADRs of T-20?
Injection site reaction
How is T-20 administered?
SQ BID
Who can receive T-20?
ART experienced patients only
What is the CCR5 receptor antagonist?
Maraviroc
What are the ADRs of Maraviroc?
Hepatotoxicity +/- systemic allergic reaction (pruritic rash, eosinophilia or elevated IgE)
Who is Maraviroc approved for?
Patients who have CCR5 tropic virus
Which CYP enzyme is Maraviroc a substrate for?
3A4
What does Maraviroc dosing depend on?
Co-administered agents
What is the MOA of integrase inhibitors?
Prevent covalent bonds from forming between integrase and host DNA -> HIV integrase unable to incorporate the viral DNA into the CD4 cell chromosome -> prevention of strand transfer and viral replication
What are RALs ADRS?
None in clinical trial
Post marketing reports: skin rashes and severe hypersensitivity
Which integrase inhibitor is preferred in pregnancy?
RAL
How is RAL metabolized?
No p450 metabolism
Glucuronidated by UGT 1A1
What is EVGs ADRs?
Diarrhea
How is EVG used?
In combination with ARVs (PIs) in treatment experienced patients
What are DTGs ADRs?
Well tolerated
Insomnia
H/A
How is DTG metabolized?
Primarily metabolized by UGT 1A1
What are the current guideline regimen for an ART naive patient?
NNRTI + 2 NRTIs OR PI (booster) + 2 NRTIs OR INSTI + 2 NRTIs
What is the preferred PI regimen for an ART naive patient?
Darunavir/ritonavir + FTC/TDF
OR
Darunavir/ritonavir + FTC/TAF
What are the preferred integrase inhibitor regimen for an ART naive patient?
Raltegravir + FTC/TDF or FTC/TAF OR Elvitegravir/cobi/FTC/TDF OR Elvitegravir/cobi/FTC/TDF OR Dolutegravir + FTC/TDF OR Dolutegravir/abacavir/lamivudine
Which integrase inhibitor regimens can you not use if CrCl < 70?
Stribild and Genvoya
What labs do you get at baseline?
Plasma HIV RNA (viral load), CD4 count Chem-7, LFTs, CBC/diff Fasting lipids Other serologies (CMV, Toxo, Crypto, RPR, Hep A/B/C HLA B*5701 genetic screening
What do we monitor for at 2 weeks after treatment initiation?
Side effects
Adherence
Can obtain VL and CD4 count
What do we monitor at 4-6 weeks?
Side effects
Adherence
VL (should decrease by at least 1 log)
CD4 count
How often should the patient be checked once stable and what is monitored?
Every 3-6 months VL CD4 Chem-7 CBC U/A (if on tenofovir)
What is virologic suppression?
A confirmed HIV RNA level below the limit of assay detection
What is virologic failure?
The inability to achieve or maintain suppression of viral replication (< 200 HIV RNA level)
What is incomplete virologic response?
Two consecutive plasma HIV RNA levels > 200 after 24 weeks on an ARV regimen. Baseline HIV RNA may affect the time course of response, and some regimens willl take longer than others to suppress HIV RNA levels.
What is virologic rebound?
Confirmed detectable HIV RNA (to > 200) after virologic suppression
What is persistent low-level viremia?
Confirmed detectable HIV RNA levels that are < 1000
What is virologic blip?
After virologic suppression, an isolated detectable HIV RNA level that is followed by a return to virologic suppression.
When do you consider switching the drug regimen of a patient?
When adherence, tolerability, and PK causes of treatment failure have been ruled out consider the following:
- Virologic failure
- Immunologic Failure
- Clinical Failure
- Intolerable toxicity
What is immunologic failure?
The failure to achieve and maintain an adequate CD4 response despite virologic suppression.
Increases in CD4 counts in ARV-naive patients with intial ARV regimens are approximately 150 over the first year
What is clinical failure?
Occurence or recurrence of HIV-related events (after at least 3 months on HAART)