Medicine & USMLE


  1. Oseltamivir, Zanamivir
  2. Acyclovir (Famciclovir, Valacyclovir)
  3. Ganciclovir
  4. Foscarnet
  5. Cidofovir
  6. NRTIs
  7. NNRTIs
  8. Integrase Inhibitors
  9. Protease Inhibitors
  10. Entry Inhibitors (Enfuvirtide, Maraviroc)
  11. NS5A Inhibitors
  12. NS5B Inhibitors
  13. NS3/4A Inhibitors


NNRTIs, or non-nucleoside reverse transcriptase inhibitors, are drugs that are used to treat HIV. The two most common NNRTIs  include Efavirenz and Nevirapine, although a drug used more rarely is Delavirdine. As the name, non-nucleoside reverse transcriptase inhibitors suggests, these drugs work by inhibiting HIV’s reverse transcriptase in a non-competitive manner.  Also, since these drugs are not nucleosides, they do not need to be phosphorylated in order to be active.  Side effects common to all NNRTIs include skin rash, hepatotoxicity, and teratogenicity. Efavirenz specifically can cause vivid dreams.

Key Points

  • Non-nucleoside reverse transcriptase inhibitors (NNRTIs)
    • Drug Names
      • Efavirenz
      • Nevirapine
      • Delavirdine
    • Mechanism
      • Inhibits retroviral reverse transcriptase
        • Binds to reverse transcriptase at a different site than NRTIs
        • Inhibits the synthesis of DNA from viral RNA template
      • Do not require phosphorylation to be active
        • Do not function by competing with nucleotides (hence the NON-nucleoside name)
    • Clinical Use
      • HIV
        • Highly active against HIV-1 but not HIV-2
        • Best used in conjunction with NRTIs
    • Adverse Effects
      • Rash
        • May cause Stevens-Johnson Syndrome (SJS) or toxic epidermal necrolysis (TEN)
      • Hepatotoxicity
        • Hepatic failure is rare but may be potentially life-threatening
      • Vivid dreams (Efavirenz)
      • Teratogenic
        • Teratogenic effects proven in rats and monkeys but not demonstrated in humans
        • Generally avoided in pregnant women