NRTIs mechanism

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

Animations depicting mechanisms of other antiretrovirals


Katzung, B. “Basic & Clinical Pharmacology”, 11th Edition. Mc Graw Hill Medical: 2009

Recommended reading

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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