HIV Therapies Flashcards
when should you start HIV therapy for a newly diagnosed patient
offer therapy ASAP (as soon as the money if available)
AIDS-defining criteria
- CD4+ count < 200
- AIDS-defining conditions (PCP, etc)
benefits of antiretroviral therapy for HIV patients
*increasing CD4 count
*preventing transmission of HIV
*reducing risk of opportunistic infections
*reducing risk of cardiovascular events
*reducing risk of kidney disease
what does “U = U” principle mean
undetectable = untransmissible
*if HIV viral load is “undetectable” (< 20), the chance of transmitting HIV to a partner approaches zero
recommended combination therapy for most people with HIV (classes of drugs)
2 NRTIs and 1 INSTI
NRTIs
nucleoside reverse transcriptase inhibitor
aka “nukes”
NNRTIs
non-nucleotide reverse transcriptase inhibitor
PIs
protease inhibitor
INSTIs
integrase strand transfer inhibitor
NRTI mechanism of action
nucleotide analogues that induce chain termination at the level of the reverse transcriptase
*make sure you choose nukes that are analogs for different nucleosides (ex. a G analog and a C analog)
commonly used NRTIs
abacavir (G analog)
emtricitabine (C analog)
lamivudine (C analog)
tenofovir (A analog)
tenofovir disoproxil fumurate (TDF)
*risk of nephrotoxicity or decreased bone mineral density
*high daily dose
tenofivir alafenamide (TAF)
*improved intracellular uptake, therefore lower dose required
*reduced risk of kidney/bone toxicity
*associated with weight gain and increased cholesterol
abacavir hypersensitivity gene
associated with HLA B57:01 (must test prior to prescribing abacavir)
abacavir hypersensitivity symptoms
flu symptoms + RASH:
-fever
-GI (nausea and vomiting)
-fatigue
-respiratory (cough, SOB, sore throat)
***rash
examples of NNRTIs
-rilpivirine
-etravirine
-doravirine
3 most common single tablet regimens for HIV
- Biktarvy
- Triumeq
- Dovato
Biktarvy composition for HIV tx
emtricitabine (NRTI)
TAF (NRTI)
bictegravir (INSTI)
PROBABLY THE BEST ONE
Triumeq composition for HIV tx
lamivudine (NRTI)
abacavir (NRTI)
dolutegravir (INSTI)
**REQUIRES HLA B57:01 TESTING
Dovato composition for HIV tx
lamivudine (NRTI)
dolutegravir (INSTI)
ritonavir use - pharmacokinetics
*used as a pharmacokinetic enhancer (“boosting agent” for the other protease inhibitor)
*inhibits CYP450, allowing the other protease inhibitor to reach higher concentrations in the body
what drugs are important for the HIV regimen in patients co-infected with hepatitis B
- emtricitabine OR lamivudine
AND - TENOFIVIR (either TAF or TDF)
resistance in HIV
*usually from reverse transcriptase mutations
*can also be protease or integrase mutations
genotype resistance testing in HIV
*detects codon mutations in reverse transcriptase, protease, or integrase genes that confer resistance to specific drugs
pre-exposure HIV prophylaxis (PrEP) regimen
emtricitabine + tenofovir (TAF or TDF)
benefit depends on adherence
HIV regimen for someone previously on PrEP
*do NOT use an INTEGRASE inhibitor (good chance he has INSTI resistance)
*2 NRTIs + 1 PI
