L23- Antiretroviral Drugs, HIV Flashcards
describe the 4 F’s of HIV progression
Flu-like Sxs (acute HIV)
Feels fine (chronic latent HIV, asymptomatic)
Falling T cell count (<200 = AIDS)
Final crisis
HIV treatment goals:
- (1) generally for patient
- (2) in terms of function and lab values
- (3) in terms of prevention
1- reduce HIV related morbidity, prolong survival, improve quality of life
2- restore/preserve immune function, maximally suppress viral load (<50 copies/mL = undetectable)
3- prevent vertical transmission
(1) % chance of vertical transmission of HIV w/o Tx
(2) % with Tx
1- 20-30% (no Tx)
2- <0.5% (w/ Tx)
describe HAART
highly active antiretroviral treatment:
-3 active drugs from at least 2 drug classes (of the 6 classes)
anti-HIV therapy is usually initiated when…. (in uncomplicated cases)
CD4 T cell count <500 cells/mm^3
list the situations where there is urgency to initiate anti-HIV therapy
-Pregnancy- to avoid vertical transmission
- AIDS defining conditions
- acute opportunistic infections
- HIV-associated nephropathy (possible CKD)
- lower CD4 cell counts
- acute/early infection
- HepB or HepC co-infection
HAART:
- usually undetectable levels of viral load occurs w/in (1) timeframe
- (2) list the many predictors for successful Tx
1- 12-24 wks
2: -low baseline viral count ARV therapy: -high potency -tolerability -convenience and excellent adherence to Tx
list the ARV drug classes
- entry / fusion inhibitors
- NRTIs (nucleoside/tide reverse transcriptase inhibitors)
- NNRTIs (non-nucleoside/tide RTIs)
- integrase inhibitors
- protease inhibitors
- pharmacokinetic enhancers
list the entry / fusion inhibitors, ARVs
Maraviroc- entry
Enfuvirtide- fusion
(1) is the entry inhibitor of HIV by blocking (2) receptor, therefore is only effective in (3) situations.
1- maraviroc
2- CCR5 receptor (HIV co-receptor)
3- m-tropic phase // early infection (before transition to t-tropic / CXCR4)
Maraviroc:
- (1) metabolism
- (2) route of administration
- (3) AEs
1- CYP3A4
2- oral
3- well-tolerated, some risk for hepatotoxicity
(1) is the fusion inhibitor of HIV by (2) mechanism. It is approved for (3) uses.
1- enfuvirtide
2- resembles gp41 structure –> inhibits function
3- treatment experienced adults (previously on ARVs) with evidence of viral replication ++++ only for HIV-1 Tx
______ is the only ARV not given orally
enfuvirtide, fusion inhibitor / gp41 analog
-given SQ
Enfuvirtide:
- (1) AEs
- (2) importantly absent AE
1- Injection related –> hypersensitivituy reactions and eosinophilia rarely occur
2- no drug interactions
list the NRTIs
(nucleo-side/tide reverse transcriptase inhibitors) – st. zelda
- stavudine
- tenofovir
- zidovudine
- emtricitabine
- lamivudine
- didanosine
- abacavir
NRTIs:
- (1) key structural feature related to function
- (2) is the key risk with monotherapy (hint- kinda 2 things)
- (3) general metabolism feature
1- lacks 3’-OH –> stops transcription / chain termination
2- rapid resistance —> cross-resistance to other NRTIs
3- most are not metabolized by cytochrome enzymes => no drug interactions
NRTIs stop DNA transcription which importantly includes (1) and can lead to (2) AEs.
- (3) are the other common AEs
- (4) are the rare, but fatal AEs
1- inhibition of mitochondrial DNA polymerase
2- peripheral neuropathy, myopathy, lipoatrophy, lactic acidosis
3- pancreatitis, myelosuppression, cardiomyopathy
4- hepatotoxicity (lactic acidosis, hepatomegaly w/ steatosis)
______ NRTIs are associated with dyslipidemia and insulin resistance
- zidovudine
- stavudine
NRTI, Stavudine:
- (1) analog
- (use/avoid)
- (3) AEs
1- thymidine
2- avoid (‘stabs you in the back with AEs– high mitochondrial DNA polymerases)
3- peripheral neuropathy, lactici acidosis, hyperlipidemia, neuromuscular weakness