HIV Pharm (HAART ARV's) Flashcards
All antivirals share a common property of being…
Virustatic. Active only against replicating viruses, not the viruses that already exist.
What virus is HIV-2 similar to? What anti-Retrovirals work for HIV-2?
Similar to “Simian Immunodifficient Virus” (SIV). Most Dx that work for HIV-1 also works for HIV-2, with the exception of NNRTI’s.
The gene “Pol” encodes what? (3 important enzymes)
- Reverse Transcriptase w/ RNAase activity.
- Protease.
- Viral Integrase
What does “Gag” encode?
It encodes a polyprotein that’s cleaved (probably by protease) in order to release the major structural proteins of the virus (which would be inactive if not released).
What does “Env” encode?
It encodes gp 160, which contains the gp’s necessary for HIV penetration into host cells.
What makes up the gp160?
It is made up of the external gp120, and the transmembrane gp 41.
How do we go from virion RNA → dsDNA?
RNA → (reverse transcriptase) → cDNA-RNA → (Reverse Transcriptase + RNAase) → dsDNA
Which tropism is responsible for all of the acquired (naturally) infections of HIV? What does a shift to the other tropism indicate?
CCR5 Tropism, a shift to CXCR4 indicates an advanced disease (granted this advance isn’t necessary to turn to AIDS)
If there is a shift to the CXCR4 tropism, this indicates that…
There is a massive CD4+ depletion.
When should anti-Retroviral treatment begin?
Classically when CD4+ count drops below 350 cells/mm3, but recently this has been changed to “anyone who has HIV”.
What does the HAART regimen consist of?
It has a 2 NRTI backbone + an NRTI, or a boosted PI, or an Integrase Inhibitor
How does HIV gain resistance to the drugs (assuming the cause isn’t a mutation?)
Via selective pressure: all the susceptible virus will be killed by the Tx, but those that survive will replicate and thus become resistant to the Tx.
What is HIV Lipodystrophy Syndrome?
Occurs in 10-40% of patients, it basically causes metabolic syndrome:
Insulin resistance induced → causes fat redistribution and hyperlipidemia.
What is the clinical presentation of HIV Lipodystrophy Syndrome?
Lipoatrophy (Peripheral Fat wasting), Central fat accumilation (fat in breast and buffalo hump), insulin resistance, incrased blood sugar and serum cholesterol and triglycerides → Basically the symptoms we would expect to see in Cushing’s Syndrome.
What is Immune Reconstitution Inflammatory Syndrome (IRIS)?
Accelerated immune response to overt or subclinical opportunistic infections, thought to be induced because Tx of the patient finally brought up the immune system to a level where it can mount a response → body freaks out and reacts to all the pathogens that it couldn’t react to before.
What agents seems to cause the trigger for IRIS?
TB, other mycobacteria, cryptococcus, Hepatitis virus, and pneumocystis pneumonia seem to trigger this.
What dangers do non-preg women expereince with anti-Retrovirals in general?
PI’s and NRTI’s can decrease blood levels of ethinyl estradiol, norethindrone or norgestinate which leads to decreased contraceptive efficacy or increase hormone levels that increase estrogen and progesterone related toxicity.
→ Basically OC’s action will be messed up, and if taking other drugs for estrogen and progesterone those will be pushed past the Tx window, potential risk of tox.
What is the expected outcome of ARV treatment?
HIV RNA conc to be 0 within 24 weeks, or below 50 cells/mL unless the patient is non complaint. If this is not the case, then a new drug regimen is needed.
What is the protocol for HIV infected peds to take ARVs?
Under 12 months must use the drugs, disease progression is slow from ages 1-5, but fast again when older than 5 (so presumably use if under 12 months or older than 5).
What are NRTI’s, chemically speaking?
Nucleotide or nucleotide reverse transcriptase inhibitors, meaning they are synthetic analogs.
Which are the Thymadine analogs of NRTIs?
Zidovudine and Stavudine
