23: HIV Pharmacology Flashcards
What does maximal treatment due for viral mutations for drug resistance?
Prevents drug-resistance mutations in the virus
Can HIV eradication be achieved?
No not with current ART
What can occur with HIV tx interruption?
Rebound viremic, worsening immune function, increased morbidity and mortality
Current ART consists of?
3 active drugs from 2+ drug classes
How soon can viral load reduction below limits of detection be achieved after starting ART?
3-6 months
Five predictors of virologic success in ART
- Low baseline viremia
- High potency ARV regimen
- Tolerability of regimen
- Convenience of regimen
- Excellent adherence
Four most used NRTIs bc they have lower affinity for DNA polymerase y (mitochondrial)
- Emtricitabine
- Iamivudine
- Abacavir
- Tenofovir
First antiretroviral drug discovered
AZT: Zidovudine
Best dual agent combo for treatment naive pts**
- Iamivudine
2. Dolutegravir
All INSTI drugs end in what?
-gravir
PI’s and CYP3A4
All PI’s are metabolized by CYP3A4, so they all inhibit metabolism of other drugs
2 CYP3A4 inhibitors and the purpose
- Ritonavir (/r), cobicistat (/c)
2. Boosts levels of other more potent PI’s
Single exposure to nevirapine in absence of other drugs causes what?
Causes resistance in 1/3 of HIV pts (thus must be combined with other drugs)
What level of viral load is considered undetectable
<200 copies / mL
How long after first undetectable HIV test can HIV pts stop using other prevention measures with sex?
Six months
Why is combination therapy used?
Prevents mutations into resistant virus
A list of considerations that influence optimal drug choices
- HLD
- Adherence
- Pregnancy
- Infections with: HBV, HCV, Tb
- Effects of food
- Chronic dz: CKD, cirrhosis, osteoporosis, psychiatric illness, QT prolongation, cardiac dz
- Gender affirming drugs
- Low CD4 counts, high viral loads
- Presence of HLA-B5701
- Wanting one pill per day
- Substance use disorders
ART and oral contraceptives
A lot of HIV meds have significant interactions with contraceptives -> need alternative methods
Why is HIV treatment more important to maintain in older adults
- Greater risk for non-AIDS complications
- Blunted immune response
- Greater need for social services
- More adverse drug effects - need to monitor bone, kidney, metabolic, CV, cognitive, and liver health
- Faster neurocognitive decline in HIV pts
- More mood disorders from HIV drugs
Six things to evaluate when ART is failing
- Assess adherence
- Drug-drug and drug-food interactions
- Drug tolerability
- HIV RNA levels CN CD4 counts over time
- ART history
- Drug-resistant test results
How to change ART regiment when treatment is failing?
New regimen include 2-3 new fully active agents (adding a single antiretroviral agent is not recommended)
