Updated: 1/11/2022

Reverse Transcriptase Inhibitors

Review Topic
  • A 31-year-old woman is in the labor and delivery unit undergoing about to undergo a cesarean section at 38-weeks gestation. She is HIV-positive and was found to have an HIV RNA viral load of 1200 copies/mL. She has been nonadherent to her medications. She is started on intravenous zidovudine 3 hours prior to the surgery in order to decrease the risk of HIV transmission to the newborn.
  • Mechanism of action
    • nucleoside reverse transcriptase inhibitors (NRTIs)
      • NRTIs are phosphorylated inside the infected cell, inhibiting the viral reverse transcriptase and impairing viral replication
        • terminates chain elongation
          • the NRTIs lacks a 3′ OH group
        • note that these are highly active against HIV-1 and HIV-2
        • tenofovir is a nucleotide reverse transcriptase inhibitor, the others are nucleosides
    • non-nucleoside reverse transcriptase inhibitors (NNRTIs)
      • a similar mechanism of action as NRTIs; however, it binds to the viral reverse transcriptase at a different site
        • note these are highly active against HIV-1 but not HIV-2
        • NNRTIs do not require phosphorylation
  • Mechanism of resistance
    • resistance mutations (there are multiple)
  • Clinical use
    • a component of antiretroviral therapy for treating HIV
  • Adverse reactions
    • NRTIs
      • mitochondrial toxicity
        • can result in peripheral neuropathy, pancreatitis, lipoatrophy, and/or hepatic steatosis
      • lactic acidosis
      • bone marrow suppressing
    • NNRTIs
      • there are no specific class-related adverse events
        • neurologic and psychiatric side effects (efavirenz and rilpivirine)
Reverse Transcriptase Inhibitors
Abacavir (ABC)
  • Contraindicated in patients with HLA-B*5701
    • associated with increased risk of hypersensitivity 
Didanosine (ddl)
  • Associated with pancreatitis
Emtricitabine (FTC)
Lamivudine (3TC)
Stavudine (d4T)
Tenofovir (TDF)
Zidovudine (ZDV)
  • Associated with anemia
  • Can be used for
    • post-exposure prophylaxis
    • intrapartum prophylaxis
NNRTIs Comments
  • Contraindicated in pregnancy
  • Associated with vivid dreams and central nervous system symptoms
  • Contraindicated in pregnancy

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