Card Set Information
Pharm Exam antiretroviral agents
Pharm Exam 4, pt 6: ARVs
General concepts regarding ARV treatment:
- monotherapy (with NRTI) is not recommended.
- HAART or combined therapy is standard.
- treatment is based on whether pt is treatment-naieve or not.
When to treat with ARVs.
- all pts with an AIDs defining illness or CD4>350
- pregnant pts, pts with HIV-associated nephropathy, or HBV coinfection (regardless of CD4 count)
- CD4 between 350 and 500
How good must adherance be with PIs to avoid resistance?
>95% adherance (increase likelihood by decreasing pill burden)
Common AE of PIs and efavirenz
metabolic and lipodystrophy complications
- abnormal fat distribution
- cardivascular events
Hypersensitivity and abacavir
: 9 days to 6 weeks
: fever, rash, malaise
screen pts for HLA-B*5701 before starting abacavir (if present, don't use)
Nucleoside Reverse Transcriptase Inhibitors (NRTIs)
ex. AZT, ddI, stavudine, abacavir
NRTIs integrate into newly forming DNA and block propagation
all are renally cleared except abacavir
: bone marrow suppression, anemia, neutropenia
do not give with ganciclovir
may increase pigmentation of nails
acid labile, give with antacid to prevent drug breakdown
: lactic acidosis, ketoacidosis
: hypersensitivity rxn (serious and potentially lethal, d/c immediately and do not attempt to use again)
screen for HLA-B*5701
Drug interactions and ARVs
Many, many drugs interact with ARVs, must always look up interactions.
Non-nucleoside Reverse Transcriptase Inhibitor (NNRTI)
ex. nevirapine, delavirdine
lead-in dosing (start slow) to minimize incidence of rash.
if rash develops do not increase dose until rash resolves
: rash - red with or w/o itching. will resolve. continue med through rash. d/c med if rash is accompanied by fever.
Protease Inhibitors (PIs)
ex. Ritonavir, saquinavir, kaletra (combo drug)
used as a booster drug to increase levels and half-lives of other meds (p450 rxn)
Ritonavir inhibits metabolism of lopinavir, resulting in higher levels of lopinavir
not recommended to use w/o ritonavir to boost levels
Interfere with the process of viral binding to a cell, preventing infection
only ARV given sub-Q
very expensive (as are integrase inhibitors)
Genotyping and HIV
reveals genetic potential of most prevalent viral isolates in a patient
predicts resistance, not sensitivity
Phenotyping and HIV
virus is cultured in various concentrations of ARVs
sensitivity of pt's HIV strain is determined
defines how a specific drug performs agains HIV strain
expensive and relatively slow