HIV Pharmacology Flashcards
Describe the treatment goals of Antiretroviral therapy
maximal and durable suppression of of plasma viremia delays, improves or preserves CD4 T cell numbers
What are the predictors of virologic success in HIV patients
low baseline viremia high potency of ARV regimen Tolerability of Regimen Convenience of regimen Compliance
What do Nucleoside Reverse Transcriptase Inhibitors inhibit?
Reverse transcriptase by direct inhibition.
They are incorporated into DNA being made from HIV RNA and stops the process
What process must NRTIs go through to become activated?
phosphorylation
What determines NRTI toxicity and where are NRTIs universally toxic
the ability of NRTI to target only HIV reverse transcriptase without inhibiting host cell DNA polymerase
mitochondrial toxicity
Name the Thymidine analogue NRTIs
zidovudine (AZT)
stavudine
this is also the first line drug
Name the cytidine analogue NRTIs
Emtricitabine
Lamivudine
Name the guanosine analogue NRTI
abacavir
Name the adenosine analogue NRTI
tenofovir
True or false: ALL NRTI can select for resistance mutations
True
What are the toxicities associated with NRTI class
Lactic acidosis syndrome
peripheral neuropathy
pancreatitis
All due to mitochondrial toxicity
Which NRTI the only option for IV administration
zidovudine (AZT)
What are specific toxicities are possible with zidovudine
Bone marrow suppression
Skeletal muscle myopathy
Hepatic steatosis (potentially fatal)
What are the major toxicities associated with stavudine
peripheral neuropathy
NRTI most associated with lipodystrophy
Lactic Acidosis and hepatic steatosis
how effective is emtricitabine as a monotherapy to resistance
low
What other virus is emtricitabine effective against
HBV
DC of this drug can cause rebound effects
What other NRTI drug can emtricitabine be combined with as a superior combination
tenofovir
Describe the pharmacokinetics of emtricitabine
long intracellular half life (a current NRTI of choice)
excreted primarily as unchanged drug in urine
Describe the toxicity of emicitrabine
one of the lease toxic antiretroviral but prolonged use leads to hyperpigmentation of skin especially in palms and soles (most common in AA)
*Allison’s drug of choice
What antiviral drug was lamivudine co-formulated with?
tenofovir
Describe the pharmacokinetics of lamviduine
long intracellular half-life and excreted primarily as unchanged in urine
Describe the toxicity of lamivudine
one of the least toxic
What NRTI is the only guanosine analogue
abacavir
Is abacavir effective against HBV
nope
What genotype is fatally incompatible with abacavir
HLA-B*5701 - potential hypersensitivity syndrome
How is abacavir eliminated from the body
NOT CYP substrate. uses dehydrogenases and is glucuronidated
Describe the hypersensitivity syndrome in those who take abacavir
fever
abdominal/GI pain
maculopapular (looking at you allison) rash
*avoid in people with CAD due to hyplerlipidemia
How does tenofovir work as an NRTI
it is a nucleotide reverse transcriptase inhibitor
It is also approved to treat HBV
Describe the pharmacokinetics of tenofovir disoproxil fumarate
intracellular half-life of 10-50 hrs
excreted primarily as unchanged in urine
Describe the toxicities of tenofovir disoproxil fumarate
nephrotoxicity with acute tubular necrosis -> fanconi syndrome
decreased bone mineral density