SIDA & VIH
Starting antiretroviral treatment
Deciding when to start antiretroviral treatment for HIV can be difficult as there is no proven ‘right’ time. There are different views of the benefits of starting treatment earlier or later, though most guidelines recommend not starting until the advanced stages of HIV infection. It is an important decision with long-term consequences.
This page continues from our introduction to HIV & AIDS treatment.
When to start antiretroviral treatment
Where available, the CD4 test is used to determine when a person should start treatment.
The CD4 test
HIV attacks a type of immune system cell called the T-helper cell. This cell carries on its surface a protein called CD4, which HIV uses to attach itself to the cell before gaining entry.
The T-helper cell plays an important part in the immune system by helping to co-ordinate all the other cells to fight illnesses. A major reduction in the number of T-helper cells can have a serious effect on the immune system. HIV causes many T-helper cells to be damaged or destroyed; as a result, there are fewer cells available to help the immune system.
A CD4 test measures the number of T-helper cells (in a cubic millimetre of blood). Someone uninfected with HIV normally has between 500 and 1200 cells/mm3. In a person infected with HIV the CD4 count declines over a number of years. Treatment is generally recommended when the CD4 test shows fewer than 350 cells/ mm3.1 However, guidelines vary slightly between countries and these are constantly debated.
When the CD4 count reaches the recommended level to start treatment, other factors may also be taken into account, such as viral load and opportunistic infections. More information about viral load monitoring is available in continuing antiretroviral treatment.
The World Health Organisation (WHO) has a method of describing the different stages of HIV disease based on clinical symptoms. This is known as the WHO staging system for HIV disease and is useful for places that have poorly equipped medical facilities. The table below shows the WHO guidelines to starting treatment in countries with limited resources, based upon the stages of HIV disease and whether a CD4 test is available or not.2
| WHO clinical staging | CD4 testing unavailable | CD4 testing available |
|---|---|---|
| 1 | Do not treat | Treat if CD4 count is below 200 |
| 2 | Do not treat | |
| 3 | Treat |
|
| 4 | Treat | Treat irrespective of CD4 count |
Before a person starts treatment it is recommended that a basic clinical assessment should be carried out. This should include determination of existing medical conditions (such as hepatitis, TB, pregnancy, injecting drug use and major psychiatric illness), assessment of current medications (including traditional and herbal medications), weight measurement and assessment of patient readiness for therapy. If AZT is being considered then a haemoglobin measurement should be taken, and a pregnancy test should be taken if EFV is being considered.
Opportunistic infections
As the immune system becomes increasingly damaged by HIV it is more susceptible to opportunistic infections. These infections would usually be fought off by a healthy immune system, but a low CD4 cell count means opportunistic infections such as PCP (a type of pneumonia) can be life-threatening. If one of these illnesses becomes a serious problem, antiretroviral treatment may be advised immediately.
Making a decision
Treatment should only be started once the person is ready. A lot of commitment is needed, since following a drug regime can be quite demanding and in most circumstances, the treatment will have to be taken for life.
Once it is decided that treatment should be started, doctors will advise of the various HIV drugs and combinations available and which might be most suitable.
Choosing the best combination
In the developed world, there are a number of drug combinations available to choose from. There are more than 20 approved drugs belonging to five groups. It is not always easy to tell which will be the best option, since a combination that suits one person might not suit another.
The first combination of drugs that a person is given is called first line therapy. For treatment in resource-poor countries, the World Health Organisation recommends a first line regimen of one NNRTI and two NRTIs, such as AZT or tenofovir combined with 3TC or FTC.3 American guidelines recommend one NNRTI or a PI combined with two NRTIs.4
The effectiveness of the drugs depends heavily upon taking them exactly as prescribed. Therefore when choosing a combination, it is important to think about how the drugs may affect lifestyle. The combination must be right the first time, as antiretrovirals are most effective in people who have not had any treatment before.
The following issues need to be considered before starting treatment:
The effectiveness of the combination
Some combinations of antiretrovirals are more effective than others. Taking drugs randomly from the different ARV groups may result in a weak combination that doesn’t suppress the HIV infection sufficiently, ending in drug resistance. A few drugs have harmful effects when used together and should not be combined (an example is stavudine and zidovudine).
Number of pills and frequency of dosage
Some combinations - especially those involving a protease inhibitor - require swallowing many pills throughout the day, which some people find hard to do. The size of the pills can also be an issue. One option for reducing the pill burden may be to take a FDC (fixed dose combination), which combines two or more drugs in a single tablet or capsule.
Food restrictions
There are a few drugs, particularly protease inhibitors, which have to be taken with food to improve absorption rates. Some other drugs have to be taken on an empty stomach. There may be a need for lifestyle changes to accommodate the medication.
Side-effects
Side effects are the undesired effects of a drug, which can range from mild irritations to serious health problems. Common side effects should be taken into consideration when choosing a combination. It is also important to consider existing medical conditions that may be worsened by some antiretrovirals. IRIS is an illness that occurs for a small minority of patients soon after treatment is started. Continuing antiretroviral treatment has more information.
Drug interactions
When choosing a combination the interactions between other drugs should be taken into consideration. Interactions can occur between antiretrovirals and non- HIV pharmaceutical and recreational drugs. More information can be found in continuing antiretroviral treatment.
Special handling requirements
Storage can be an issue as some anti-HIV drugs have to be kept below a certain temperature to last long term. Ritonavir, for example, must be refrigerated.
Drug resistance
In some countries a drug resistance test can be carried out before treatment is started in order to determine whether the HIV is already resistant to any of the drug classes. If available the test is recommended for those who have contracted HIV from someone who is already taking treatment. Our continuing antiretroviral treatment page has more information about drug resistance.
Preparing for adherence
The term adherence means taking the drugs exactly as prescribed, on time, and following any dietary restrictions. If the treatment instructions are not followed, it is likely that the drugs will not be absorbed properly in the body. This can have serious short- and long-term consequences, such as an increase in viral load and a greater risk of developing drug resistance.
Adhering to the drug regimen can often be difficult, due to side effects or the frequency of dosage. Sometimes lifestyles changes are needed. Doctors should be able to offer advice if someone is experiencing adherence difficulties.
Pregnancy and treatment
Many studies have shown that antiretroviral drugs can be used during pregnancy. The drugs can be used to reduce a woman's viral load effectively below detection. This also greatly reduces the risk of the baby becoming infected.
Find out more about HIV and pregnancy.
Treatment for children
The progression of HIV in children is monitored through viral load and CD4 tests, as with adult treatment, but because the CD4 and viral load levels vary in children (especially between ages 1 to 4) they must be treated on an individual basis. CD4 counts in children are generally much higher than in adults, and change with the child’s age. This means that adult guidelines on when to start antiretroviral treatment do not apply.
Find out more about HIV treatment for children.
More information
AVERT.org has information about continuing antiretroviral treatment, including advice about avoiding drug resistance and coping with side effects.
WHERE NEXT ?
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Page updated by Gemma Spink
References:
- Department of Health and Human Services (2008, 29th January) ‘Guidelines for the use of antiretroviral agents in HIV-1 infected adults and adolescents’.
- World Health Organisation (August 2006) 'Antiretroviral therapy for HIV infection in adults and adolescents in resource-limited settings: towards universal access - Recommendations for a public health approach'
- World Health Organisation (2008, August) ‘Priority interventions: HIV/AIDS prevention, treatment and care in the health sector’.
- Department of Health and Human Services (2008, 29th January) ‘Guidelines for the use of antiretroviral agents in HIV-1 infected adults and adolescents’.
Disclaimer
www.avert.org is an information resource to be used for educational purposes only. The information is not intended to serve as a substitute for professional medical advice and we recommend that all decisions about your treatment or products you wish to use should be discussed thoroughly and frankly with your doctor.