HIV Antivirals Flashcards
Is HIV an RNA or DNA virus
RNA retrovirus
Which cells do HIV infect
CD4
Stages of HIV
acute infection – clinical latency – symptomatic – AIDS
AIDS criteria
CD4 <200 or AIDS defining illness
Normal CD4 levels
800-1200
Types of HIV antiviral drugs that block viral entry into cells
CCR5 antagonists
fusion inhibitors
(New: CD4 lymphocyte post-attachment inhibitor, GT120 inhibitor)
CCR5 antagonist prototype
Maraviroc (Selzentry)
block ability for co-receptor (CCR5) to bind with GP 120 on HIV virion blocking entry of HIV into CD4 cell
CCR5 antagonist
Which category of HIV drug would you test to see if patient’s HIV strain is CCR5-tropic
CCR5 antagonist
Two coreceptors that HIV drug binds to
CXCR4 and CCR5 coreceptors
When is Selzentry used?
Usually for treatment-resistant because it modifies the host cells
Maraviroc (Selzentry) toxicity
hepatotoxicity
Which drug category blocks entry of HIV into CD4 cells by binding GP41 on the HIV envelope preventing the HIV molecule from binding to the CD4 cell and fusing the two lipid bilayer membranes
Fusion inhibitor
AE of Enfuvirtide (Fuzeon, T-20)
Injection site reactions
Which drug category inhibits the creation of viral DNA by substituting a useless nucleotide in the strand of base pairs, which prevents further base pairs to be added.
Nucleotide/nucleoside reverse transcriptase inhibitor (NRTI)
Zidovudine (AZT) drug class and SE
NRTI
anemia and neutropenia
Abacavir (Ziagen, ABC) drug class
NRTI
Test for genetic variant HLA-B*5701. Don’t use if positive
When is AZT typically used?
pregnancy and intrapartum
When is Abacavir used
early treatment, when negative for genetic variant
Which drug class binds to the active center of reverse transcriptase and causes direct inhibition
Non-nukes (NNRTI)
AE of non-nukes
rash and hypersensitivity, BBB, teratogenic
Prototype of non-nukes
Efavirenz (sustiva) but RARELY used because of neuro-psych effects
Which drug category prevents HIV genetic material from being integrated into the DNA of the CD4 cel?
Integrase inhibitors
Name formation of integrase inhibitors
*tegravir (Raltegravir, Dolutegravir, Elvitegravir)
Prototype of integrase inhibitors
raltegravir
AE of Raltegravir
well tolerated, can raise liver enzyme, weight gain, and rarely cause hypersensitivity reactions
Current treatment recommendation drug classes
integrase inhibitor and 1-2 nukes
Which drug class prevents protease enzyme from cutting HIV polyprotein. This keeps the HIV cell inactive and useless.
Protease inhibitor
Which is the most effective class of HIV drug
protease inhibitors
Why aren’t protease inhibitors always used as first line?
Lots and lots of drug interactions (manipulates CYP450), resistance to one predicts resistance to others, metabolic syndrome, increase liver enzymes, decreased cardiac conduction
Big benefit of protease inhibitors
Can reduce viral load to undetectable levels (important for both transmission and prognosis)
HAART
Highly Active Antiretroviral Therapy
Ritonavir (Norvir) and Cobicistat (Tybost) category
Pharmacokinetic enhancers: boosters
How can ritonavir (Norvir) be given in a protocol?
Low doses to boost effects of other drugs and improve tolerance
Which drug blocks CYP450 3A4 enzyme increasing the concentration of certain antiviral drugs
Cobicistat (Tybost)
In HIV, we typically use [one/multiple] drug(s) at a time
Multiple, 3-4
When resistance occurs, do we change all drugs or just one?
All drugs
Do we wait to treat patients until CD4 count gets low?
No, we treat regardless of CD4 count
What does drug therapy for HIV include
- drugs to treat HIV
- drugs to treat side effects
- drugs to prevent/treat OIs
- drugs for non-HIV conditions
c-section during pregnancy when viral load is greater than…
1000/mL
When does antiviral therapy occur in the context of pregnancy?
During pregnancy, during L&D, post-partum (treat baby with PEP)
Differentiate PEP and PrEP
Pre-Exposure Prophylaxis (PrEP)
Post-Exposure Prophylaxis (PEP)
How soon does PEP need to be administered?
most effective within 1-2 hours, needs to be administered within 72 hours
In a patient doing well on their drug therapy, CD4 count should be [low/high] and viral load should be [low/high]
cd4 high, viral load low
