What it is
Antiretroviral drugs inhibit the replication of HIV. When antiretroviral drugs are given in combination, HIV replication and immune deterioration can be delayed, and survival and quality of life improved.
Why it is Important
Effective HIV/AIDS care requires antiretroviral therapy as a treatment option. Without access to antiretroviral therapy, people living with HIV/AIDS cannot attain the fullest possible physical and mental health and cannot play their fullest role as actors in the fight against the epidemic, because their life expectancy will be too short. Health care workers will remain disempowered and cannot contribute to the fight against HIV to the fullest of their potential. Children will be orphaned earlier, stigma and discrimination will continue to be fuelled by the perception that HIV infection is a death sentence.
How it is Done
All people who need antiretroviral therapy should have access to it. WHO proposed as a target that by 2005, 3 million people should have access, and called for the adoption in resource-limited settings of a public health approach to antiretroviral treatment as a tool to reach this goal.
Selection of ARV treatment regimens for programmes and individual patients should consider: potency, frequency of dosage, side effects, maintenance of future treatment options, the anticipated adherence of the patient population to a regimen, need for storage, concurrent conditions, the potential for resistant viral strains, and cost and access. Additional considerations may include access to only a limited number of ARV drugs, limited health service infrastructure, the need to deliver drugs to rural areas, a high incidence of tuberculosis and hepatitis B and/or C, and the presence of varied HIV groups and subtypes.
WHO recommends that in ARV treatment programmes in resource-limited settings HIV infected adolescents and adults should start ARV therapy when they have clinical AIDS, regardless of CD4 count. When total lymphocyte count can be assessed, in addition people with WHO stage II or III HIV disease should be offered treatment. When CD4 counts are available, all HIV infected people with less than 200 CD4 cells/mm3 should be offered treatment.
WHO recommends that in resource-limited settings a single first-line regimen should be identified for the treatment of the majority of new patients. This regimen would consist of 2 nucleoside analogs and either a non-nucleoside or abacavir, or a protease inhibitor. Zidovudine (ZDV)/3TC is the initial recommendation for a dual nucleoside analog with d4T/3TC, ZDV/ddI and ddI/3TC as possible alternatives. Efavirenz and nevirapine are recommended non-nucleosides, while recommended protease inhibitors include ritonavir-boosted PIs (indinavir, lopinavir, saquinavir) or nelfinavir. A second line regimen should be chosen to substitute first line regimens when needed (for toxicity or treatment failure).
Clinical assessment prior to the initiation of ART includes documentation of past medical history, identification of current and past HIV related illnesses, identification of co-existing medical conditions and medications in use that may influence choice of therapy (such as TB or pregnancy) as well as current symptoms and physical signs.
Minimum laboratory tests include an HIV antibody test, and (if ZDV is part of the regimen) haemoglobin or hematocrit level. Highly desirable tests are white blood cell count and differential, CD4 count, serum alanine, aspartate aminotransferase level, serum creatinine, blood urea nitrogen, serum glucose, bilirubin, amylase and serum lipids, and pregnancy tests for women.
Toxicity should be monitored clinically based on patient reports and physical examination, supplemented by a limited number of laboratory tests depending on the symptoms that arise and the specific combination regimen that is used.
Treatment failure will require that a second line regimen be used. When a change in treatment is indicated because of toxicity or resistance, either an entirely new second line regimen can be prescribed, or, when the toxicity or resistance is related to an identifiable drug in the regimen, the offending drug can be replaced.
Countries planning to implement ART programmes should also concurrently implement an HIV drug resistance sentinel surveillance system. This will allow the detection of drug resistance at the population level and allow to modify recommended treatment regimens accordingly.
Human Resources, Infrastructure and Supplies Required
For the successful use of ARVs there should be access to specific services and facilities:
- HIV counselling and testing and follow-up counselling services to ensure psychosocial support and adherence to treatment;
- Capacity to appropriately manage HIV related illness and opportunistic infections;
- A laboratory that provides tests for monitoring treatment;
- A continuous supply of antiretrovirals and medicines for the treatment of opportunistic infections and other HIV related illnesses;
- Reliable regulatory mechanisms.
In addition, there is a need for adequately trained doctors, clinical officers, nurses, laboratory technicians, pharmacists, counsellors and clerks to provide the services required. Last, there needs to be a reliable source of financing of the services and medicines provided. In many settings there are already some people who can provide quality services, there is already some infrastructure that can be used, and there are already some people who can pay for the service they need. In these settings treatment should be offered now, while resources are sought and the health service is strengthened to do more in the future. Today, with the increased availability of funds through the Global Fund, the World Bank and other donors, there is a considerable window of opportunity for developing countries to scale up access to antiretroviral therapy.
The World Health Organization's model list of Essential Medicines has recently included antiretroviral compounds. At present the cost of ART in least developed countries ranges from US$ 300- US$ 1200 per annum. The cost of monitoring antiretroviral therapy varies with its complexity. It is expected that the cost of ART in developing countries will decrease if their utilization increases significantly.