How do NRTIs and NNRTIs work?
NNRTIs work by binding to the HIV enzyme called reverse transcriptase, which is essential to the viral replication process, and therefore blocking HIV from making copies of itself. Dapivirine is an example of an NNRTI. NRTIs work by mimicking nucleotides that are the building blocks of viral DNA.
What phosphorylates NRTIs?
In order to be incorporated into the viral DNA, NRTIs must be activated in the cell by the addition of three phosphate groups to their deoxyribose moiety, to form NRTI triphosphates. This phosphorylation step is carried out by cellular kinase enzymes.
What is the mechanism of action of NRTIs?
Nucleoside Reverse Transcriptase Inhibitors (NRTIs) inhibit reverse transcription by causing chain termination after they have been incorporated into viral DNA. For these drugs to be active they need to be phosphorylated intracellularly. This was the first group of antiretroviral agents to be used against HIV.
What are the classes of Arvs?
These drugs are distributed into six distinct classes based on their molecular mechanism and resistance profiles: (1) nucleoside-analog reverse transcriptase inhibitors (NNRTIs), (2) non–nucleoside reverse transcriptase inhibitors (NNRTIs), (3) integrase inhibitors, (4) protease inhibitors (PIs), (5) fusion inhibitors.
What is the difference between NNRTIs and NRTIs?
The NNRTIs differ from the NRTIs in that they do not have a nucleoside structure and do not depend on phosphorylation for activity. They function as noncompetitive substrate analogues and are selective inhibitors of HIV-1, with no activity against HIV-2 strains or even HIV-1 type O.
What is the right time to take Arvs?
Taking your medicines at the right time, as close as possible to the same time each day. Usually, this means taking the drug within a two-hour window (up to one hour either side of the set time). Following any instructions about food.
What drugs are Nrti?
They include:
- Abacavir (Ziagen)
- Emtricitabine (Emtriva)
- Lamivudine (Epivir)
- Tenofovir alafenamide (Vemlidy)
- Tenofovir disoproxil fumarate (Viread)
- Zidovudine (Retrovir)
How do NRTIs inhibit reverse transcriptase?
NRTIs lack a 3′-hydroxyl group at the 2′-deoxyribosyl moiety and will have either a nucleoside or nucleotide as a base. Due to the missing 3’hydroxyl group, the NRTI prevents the formation of a 3′-5′-phosphodiester bond in growing DNA chains and can prevent replication of the virus.