Antiretroviral drugs

Nicholas Medland1, Vincent Cornelisse2, Don Smith3

  1. The Kirby Institute, University of NSW, Sydney, NSW
  2. Kirketon Road Centre, Sydney, NSW
  3. The Albion Centre, Surry Hills, Sydney, NSW

Last reviewed: November 2019

Antiretroviral drug classes

The six classes of antiretroviral drugs currently licensed for use in Australia are:

  • Nucleoside and nucleotide reverse transcriptase inhibitors (NRTIs);
  • Non-nucleoside reverse transcriptase inhibitors (NNRTIs);
  • Protease inhibitors (PIs);
  • Integrase strand transfer inhibitors (INSTIs);
  • Entry inhibitors: Fusion inhibitors;
  • Attachment inhibitors: CCR5 inhibitors.

Since 2015, antiretroviral therapy (ART) in Australia has been recommended for all patients diagnosed with HIV infection irrespective of clinical stage, HIV viral load and CD4+ T cell count (1, 2). This is based on large randomised controlled trials with clinical endpoints which demonstrated that all HIV-infected individuals benefit from ART (3, 4). In addition to clinical benefit to the HIV-infected individual, ART also prevents HIV transmission (5-7). Australia does not have antiretroviral guidelines but ASHM has maintained a commentary on the US DHHS Guidelines, on which this chapter is based, except where stated otherwise.

In ART-naïve patients initiating ART, several factors are relevant to achieving sustained virological suppression of HIV infection. These include maximising adherence to the antiretroviral drug regimen and the use of baseline drug resistance testing to detect transmitted HIV drug resistance, where appropriate. A patient’s ability to adhere to a regimen is critical for successful treatment, as poor adherence can lead to virological failure, the development of HIV drug resistance mutations, and decreased patient survival.[8][9][10][11] It is therefore important to consider factors such as toxicity, pill burden and dietary restrictions which may affect the ability of a patient to adhere to a given regimen. Other important factors include co-infection with hepatitis B virus (HBV) or hepatitis C virus (HCV)  and use of illicit substances and alcohol.[12][13] The former is included because the toxicity of some antiretroviral drugs is worse in the setting of hepatitis virus co-infection,[14] and the latter because of greater risk of non-adherence and the potential for drug-drug interactions.