HIV/AIDS - Regal Flashcards
What are some general concepts to keep in mind with HIV treatment?
Goal is fully undetectable levels of virus
The lower the viral RNA can be driven, the lower the rate of accumulation of drug resistant mutants will be & the longer the therapeutic effect will last
Maximally inhibit viral replication
To achieve maximal and durable suppression of viral RNA, drug combinations and patient compliance are required
Resistance testing recommended before starting therapy
Monitor HIV RNA levels (viral load) and CD4+ cell count
increased viral load may indicate development of drug resistance
Use drug combinations
but avoid contraindicated drug combinations (lists available)
Think about drug interactions
Encourage compliance
What is the MOA of Nucleoside Reverse Transcriptase Inhibitors (NRTIs)?
Competitively inhibit reverse transcriptase
in cytosol
Can be incorporated into viral DNA chain
the inhibitor binds to the DNA chain and terminates the production of DNA
What do NRTIs require to become active?
Phosphorylation by cellular enzymes to the triphosphate form
What are the four NRTI drugs that we need to know?
Zidovudine (Azidothymidine or AZT)
Lamivudine
Emtricitabine
Abacavir
What are the general adverse effects of NRTIs?
Potentially fatal syndrome of lactic acidosis with hepatic steatosis
probably due to mitochondrial toxicity
Associated with fat redistribution and hyperlipidemia
skinny arms and a fat trunk
What is unique about Zidovudine compared to the other NRTI drugs?
granulocytopenia and anemia in up to 45% of treated patients
hematological monitoring at 2 week intervals
CNS disturbances:
severe headache
nausea
insomnia
malaise
What is unique about Lamivudine & Emtricitabine compared to the other NRTI drugs?
Probably best tolerated of the NRTIs
Also active against Hepatitis B
What is unique about Abacavir compared to the other NRTI drugs?
hypersensitivity reactions can be a problem
What is the MOA of Nucleotide Reverse Transcriptase Inhibitors (NRTI)?
Same as Nucleoside Reverse Transcriptase Inhibitors:
Competitively inhibit reverse transcriptase
in cytosol
Can be incorporated into viral DNA chain
the inhibitor binds to the DNA chain and terminates the production of DNA
What is the difference between a nucleotide and a nucleoside?
Nucleotides are phosphorylated nucleosides.
What is the one Nucleotide Reverse Transcriptase Inhibitor drug that we need to know?
Tenofovir
What are adverse side effects of Tenofovir?
Most common: N/V Diarrhea potential for renal failure Potentially fatal syndrome of lactic acidosis with hepatic steatosis probably due to mitochondrila toxicity
What is the MOA of Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs)?
Bind directly to the reverse transcriptase at a site distinct from that of the NRTI
enzyme cannot produce viral DNA
Does not require phosphorylation for activity
What are the two Non-Nucleoside Reverse Transcriptase Inhibitor drugs that we need to know?
Efavirenz
Etravirine
Is there cross resistance with NNRTIs and NRTIs and protease inhibitors?
NO