HIV and opportunistic Infections Med Chem Flashcards
HIV
-retrovirus (lentivirus)
-double stranded RNA
-infects CD4+T cells (T-tropic ) and macrophages (m-tropic)
-uses enzyme reverse transcriptase
viral rna is converted to DNA
CXCR4
major coreceptor for T-cell tropic strains
involved in the progression to AIDS
CCR5
major coreceptor for macrophage-tropic strains
involved in the transmission of infection
- strategy to block infection
History of HIV treatment
prior to 1996: one or two NRTIs
In 1996: HIV protease inhibitors were introduced
three active antiretroviral agent were shown to inhibit
-HIV replication
-reverse immune deficiency
-decrease morbidity and mortality
how doe HIV-1 enter target cells
primary receptor : CD4
failed strategy of HIV
soluble CD4
acute primary HIV infections
treat with combination antiviral therapy to suppress virus replication to levels below the detection of plasma HIV RNA assays
Patient under effective HIV treatment with viral loads below detectable
should consider infectious and should be counseled to avoid sexual and drug use behaviors
Long term non progress ors of HIV
ppl infected by HIV for over 10 years and never convert into AID
CD4+ cell levels
indicator for initiation of anti-retroviral treatment
treatment recommended for
-a CD4 lymphocyte count below 350 cells/mm^3
-asymptomatic with CD4 count between 350-400 cells/mm^3
->500 CD4 cells/mm^3 (early treatment)
Pharmacological therapy of HIV
-inhibition of viral replication
-inhibition of HIV entry and viral fusion integration
under investigation
-microbicides to prevent HIV associated infections
-vaccination to simulate a more immune response ( not FDA approved yet)
-restoration of the immune system with immunomodulatora
nucleoside analogs
act as a chin terminators or inhibitors at the sub strayer binding site of RT
- must be phosphorylated (3 steps) to their 5’ triphosphate form to become active inhibitors
Nucleotide analogs
already contain a phosphate group and only goes through 3 steps to become active
what does the 5’triphosphate of the NRTI’s compete with for binding to reverse transcriptase leading to viral DNA chain termination
2’deoxynucleoside’s 5’triphosphate
6 agents of NRTI
cytosine analog
-emtricitabine
-lamivudine
adenosine or guanosine analog
-abacavir sulfate
-didanosine
thymidine analog
-stavudine
-zidovudine
NtRTI drug
adenosine derived nucleotide reverse transcriptase inhibitor
-tenofavir disoproxil fumarate (functions as prodrug)
non nucleoside analoge reverse transcriptase inhibitor MOA
inhibit DNA replication by binding at the allosteric non bonding site of RT, causing a conformational change of the active site
do not require bioactivation by kinase
