Anti-virals Flashcards
What does a HIV antiretroviral regimen generally comprise of?
2 nucleoside reverse transcriptase inhibitors and either a(n)
integrase strand transfer inhibitor OR
protease inhibitor OR
non-nucleoside reverse transcriptase inhibitor.
Name 2 examples of long-term toxicities associated with HIV antiretroviral treatment
- metabolic syndrome
2. lipodystrophy syndrome
Name the nucleoside reverse transcriptase inhibitors (NRTIs) and state which riboside’s analogue they each are
- Abacavir - guanosine
- Emtricitabine - cytosine
- Tenofovir - adenosine
- Lamivudine - cytosine
- Zidovudine - thymidine
What is the mechanism of action of nucleoside reverse transcriptase inhibitors?
NRTIs are analogs of native ribosides.
Upon cell entry, they are phosphorylated to the corresponding triphosphate analog, which is preferentially incorporated into the viral DNA by reverse transcriptases. Because the 3′-OH group is not present, a 3′,5′-phosphodiester bond between an incoming nucleoside triphosphate and the growing DNA chain cannot be formed, and DNA chain elongation is terminated.
Which 2 NRTIs should not be co-administered?
Emtricitabine and lamivudine as they are both cytosine analogues
Which NRTIs can also be used in the management of Hepatitis B?
- Emtricitabine
- Tenofovir
- Lamivudine
(An ART regimen for patients with both HIV and HBV should include (TAF or TDF) plus (3TC or FTC))
Name 2 advantages of tenofovir alafenamide over tenofovir disproxil fumarate?
Tenofovir alafenamide has more favorable effects on renal and bone markers
Which NRTI can only be used in HLA-B5701–negative individuals?
A test that detects the presence of HLA-B5701. HLA-B5701 is a genetic variation that is linked to hypersensitivity to the antiretroviral (ARV) drug abacavir. A person who tests positive for HLA-B5701 should not use abacavir or any other abacavir-containing medicine.
Abacavir
What is the mechanism of action of integrase inhibitors?
The inhibitor binds and inhibits the catalytic site of the HIV integrase, which terminates integration of HIV DNA into the host genome.
Name 3 examples of integrase inhibitors
- Dolutegravir
- Elvitegravir
- Raltegravir
What is the mechanism of action of protease inhibitors?
Protease inhibitors bind to the site where protein cutting occurs, and prevent the viral enzyme protease from releasing the individual core proteins.
Name 2 examples of protease inhibitors
- Darunavir
2. Lopinavir
Name at least 3 adverse effects associated with protease inhibitors
- GI disturbances: Nausea, vomiting, and diarrhea.
- Hyperglycaemia
- Hyperlipidaemia
- Hepatic injury
- Lipodystrophy
What is the mechanism of action via which the pharmacokinetic enhancer such as ritonavir works?
Low doses of ritonavir used have no significant anti-protease activity, but sufficient CYP450- inhibitory activity that interferes with the metabolism of protease inhibitors.
Drug-drug interactions is a common problem associated with which class of HIV anti-viral drugs?
Protease inhibitors (Drug interactions are a common problem for all protease inhibitors as they are not only substrates but also potent inhibitors of CYP450 isoenzymes.)
