Nucleoside analog reverse transcriptase inhibitors (NRTIs) are nucleoside analogues that act as competitive inhibitors of HIV-1 reverse transcriptase. As shown in the animation, these drugs compete with nucleoside triphosphates for access to reverse transcriptase.
All NRTIs lack a 3-hydroxyl group; thus, their incorporation into a growing DNA chain results in its termination. They require intracytoplasmic activation via phosphorylation by cellular enzymes to the triphosphate form. Most have activity against HIV-2 as well as HIV-1.
NRTIs mechanism of action
List of NRTIs
- Zidovudine or azidothymidine (AZT) (also called ZDV): first approved drug in its class.
- Didanosine (ddI): second FDA-approved drug for the treatment of HIV infection.
- Tenofovir (TDF): first nucleotide analog. It has significant drug interactions.
- Lamivudine (3TC): also used in the treatment of HBV infection.
- Emtricitabine (FTC): acts as an inhibitor of HBV and HIV transcriptase.
- Abacavir (ABC): a guanosine analog.
Animations depicting mechanisms of other antiretrovirals
References
Katzung, B. “Basic & Clinical Pharmacology”, 11th Edition. Mc Graw Hill Medical: 2009
Recommended reading
- The Sanford Guide to HIV/AIDS Therapy 2010
- Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases (2009)
- HIV Essentials 2010
- HIV Diversity and Antiretroviral Resistance: Epidemiology, Recombination, HAART
About the animation author
.Dr. Gary Kaiser is a Professor of Microbiology at The Community College of Baltimore County, Catonsville Campus located in Baltimore, Maryland. Make sure you visit his excellent microbiology website: The Grapes of Staph.
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