Considerations before starting antiretroviral therapy for HIV infection

Antiretroviral therapy is recommended for all people with HIV infection, regardless of CD4 cell count, because it reduces morbidity and mortalityEuropean AIDS Clinical Society (EACS), 2022Gandhi, 2023Panel on Antiretroviral Guidelines for Adults and Adolescents, 2023Waters, 2022. For more detailed information, see the Australian and international HIV treatment guidelines listed in Australian and international HIV guidelines.

In symptomatic patients with newly diagnosed HIV and those with severe immunodeficiency, exclude other infections. For advice on when to start antiretroviral therapy in patients with other infections, see Opportunistic and co-infections in adults with HIV. For patients without opportunistic or co-infections, start antiretroviral therapy as soon as possible.

Once started, treatment should be continued indefinitely without interruption, unless oral therapy cannot be taken or severe toxicity develops.

Appropriate tests to perform before starting antiretroviral therapy are listed in Appropriate tests to perform before starting antiretroviral therapy in Australia. These tests can be used to stage HIV disease, and guide when to start antiretroviral therapy and which regimen to use. Antiretroviral drug choice and monitoring also depend on:

  • comorbidities
  • the potential for metabolic and other adverse effects
  • co-administered drugs
  • social factors.

Immune reconstitution inflammatory syndrome (IRIS) is the development of an inflammatory reaction to latent or subclinical infection with organisms such as Mycobacterium avium complex, Mycobacterium tuberculosis, Cryptococcus neoformans, cytomegalovirus or varicella zoster virus. IRIS can occur shortly after starting any combination antiretroviral regimen, especially in patients with a low CD4 count (less than 100 cells/microlitre). Ensure opportunistic infections are excluded in symptomatic and immunodeficient asymptomatic patients and that appropriate screening for specific organisms occurs before starting antiretroviral therapy.

Figure 1. Appropriate tests to perform before starting antiretroviral therapy in Australia
  • HIV antibody/antigen (if previous results are not available or if HIV RNA is below the assay’s limit of detection)
  • CD4 cell count
  • plasma HIV RNA (viral load)
  • HIV genotypic resistance as soon as possible after diagnosis – viral amplification for resistance testing is not always successful if HIV RNA is less than 1000 copies/mL
  • HLA-B*5701 allele, if treatment with abacavir is being considered (for further information, see Practice points for initial antiretroviral therapy)
  • hepatitis B and C virus serology
  • full blood count, serum electrolytes, serum phosphate, liver biochemistry, serum creatinine, estimated glomerular filtration rate (eGFR), and urine protein-to-creatinine ratio
  • random blood glucose and serum lipid profile
  • serum cryptococcal antigen, if CD4 cell count is less than 100 cells/microlitreBisson, 2013Ford, 2018McKenney, 2015Mfinanga, 2015World Health Organization (WHO), 2018
  • tests to exclude opportunistic and co-infections if the patient is symptomatic.

Newly diagnosed patients need additional tests that are not specifically related to starting antiretroviral therapy – see the Australian and international guidelines listed in Australian and international HIV guidelines.

Contact tracing (partner notification) is required when a patient is diagnosed with HIV infection or other sexually transmissible infections. For details, see STI contact tracing.