HIV treatment breaks


Key points

  • Stopping your HIV medications is not recommended.
  • Studies have found that people taking an HIV drug holiday are more likely to become ill.
  • If you’re thinking of stopping your meds, talk to your doctor about your concerns and your options.

Taking a planned break from your HIV treatment is sometimes called a ‘structured treatment interruption'. Sometimes it’s also referred to as a 'drug holiday'. Treatment breaks are not recommended in current HIV treatment guidelines.

There has been a lot of research into treatment breaks, and this has shown that there tend to be more risks than benefits. In particular, a big study which was stopped in 2006 (the SMART study) found that people who took treatment breaks guided by their CD4 cell count risked becoming ill not only because of HIV-related illnesses, but also because of heart, kidney, and liver disease and some cancers.

This page discusses the scientific research on treatment breaks as well as the possible risks. 

Why not to take a treatment break: the SMART study

The SMART (Strategies for the Management of Antiretroviral Therapy) study recruited people taking HIV treatment with a CD4 cell count above 350. Participants were divided into two groups: the first group continued to take HIV treatment as normal, the other group stopped treatment, restarting when their CD4 cell count fell to around 250 (the point where people start to become more vulnerable to serious infections), and then stopping again when their CD4 cell count once again reached 350. Among other things, the researchers wanted to see if people taking treatment breaks remained well, and how many avoided the side-effects of anti-HIV drugs.

However, in January 2006 the study was stopped early because 4% of people who interrupted their HIV treatment became ill compared to only 2% of people who took their HIV drugs all the time. The researchers found that people taking treatment breaks were more than twice as likely to become ill or die than people taking continuous HIV treatment.

As well as an increased risk of HIV disease progression, people taking treatment breaks also had an increased risk of other illnesses such as cardiovascular disease, and kidney or liver disease. This was a surprise, as these conditions can be side-effects of HIV treatment and the study’s researchers had expected to see more of these illnesses in people taking HIV treatment all the time.

The researchers also found that people who took treatment breaks had a lower quality of life.

It is thought that a reason why people taking treatment breaks experienced more illness was because they spent more time with low CD4 cell counts and detectable viral loads, increasing the risk of HIV disease progression.

Why not to take a treatment break: the DART study

Shortly after the SMART study was stopped, the treatment interruption arm of another study was also stopped.

Researchers were looking at fixed cycles of HIV treatment in people who had a CD4 cell count of 300 or more. In the DART (Development of Anti-Retroviral Therapy in Africa) study, people with a CD4 cell count of over 300 were divided into two groups, to either receive continuous HIV treatment or to take twelve-week cycles of HIV treatment followed by twelve-week breaks. However, the treatment interruption arm of the study was stopped early and all participants were advised to switch to taking their treatment all the time when the researchers noticed that people who took treatment breaks were more likely to develop HIV-related illnesses.

Current thoughts on treatment breaks

Treatment interruptions initially became a hot topic among HIV researchers after a handful of people who had previously taken HIV treatment maintained a very low viral load even when they stopped treatment. However, larger trials failed to find any benefit from stopping treatment.

Attention then turned to the value of treatment breaks guided by CD4 cell count. The SMART study has shown that there are also concerns about the safety of this approach.

The reasons why people may want to consider a treatment break also still remain: taking HIV treatment appears to need life-long commitment with the currently available drugs, with as few missed doses as possible. Many people find this difficult.


CD4 cell count

A test that measures the number of CD4 cells in the blood, thus reflecting the state of the immune system. The CD4 cell count of a person who does not have HIV can be anything between 500 and 1500. When the CD4 count of an adult falls below 200, there is a high risk of opportunistic infections and serious illnesses.

viral load

Measurement of the amount of virus in a blood sample, reported as number of HIV RNA copies per milliliter of blood plasma. Viral load is an important indicator of HIV progression and of how well treatment is working. 


treatment interruption

Taking a planned break from HIV treatment, sometimes known as a ‘drugs holiday’. As this has been shown to lead to worse outcomes, treatment interruptions are not recommended. 


A clinical trial is a research study that evaluates a treatment or intervention with human volunteers, in order to answer specific questions about its safety, efficacy and medical effects.


An essential organ involved in digestion of food and excretion of waste products from the body.

HIV treatment is becoming a lot more tolerable, but it can still cause side-effects, some of which are long-term and can cause health problems. Breaks may be considered in a few circumstances, including if you have liver damage (hepatotoxicity).

Some research has looked at short treatment breaks, such as stopping treatment at weekends. Whether short treatment breaks are a safe option depends on various factors, including the drug combination and the individual’s CD4 count over time. Given the lack of conclusive evidence, current guidelines recommend against treatment interruption or intermittent treatment.

If you are thinking of taking a break from your anti-HIV drugs speak to your doctor about how advisable and safe it is for you to do so. Carefully stopping treatment with your doctor’s assistance reduces the risk of drug resistance developing.

If you are currently taking a break from treatment make sure that you go to your HIV clinic regularly to have your CD4 cell count, viral load and health closely monitored.

Treatment breaks as part of a research study

Occasionally, scientists ask people to take a treatment break as part of a clinical trial. In general, these are early studies, working towards an HIV cure or therapeutic vaccine. You would be unlikely to personally benefit by taking part, but you would be contributing to scientific knowledge about how HIV can be controlled.

"There has been a lot of research into treatment breaks, and this has shown that there tend to be more risks than benefits."

In some of these studies, the only way of seeing if an experimental treatment works (or at least has some effect) is for the study participant to stop taking their usual HIV treatment. The researchers then closely monitor participants in order to see if their viral load becomes detectable again, how soon, and at what level. This is called an analytical treatment interruption.

As with other breaks from HIV treatment, there are risks to having an analytical treatment interruption. To minimise the risks, only people with well-controlled HIV, a functional immune system and no other health concerns should be invited to take an analytical treatment interruption. Researchers may also ask about your sexual partner(s). Moreover, your health would be closely monitored if you took part.

As with all clinical trials, it’s important to make sure you fully understand what’s involved before agreeing to take part. If you join a trial but change your mind, you have the right to withdraw at any time without giving a reason.

Possible risks of treatment breaks

  • Rising viral load and falling CD4 could mean a risk of opportunistic infections and illness.
  • Possible increased risk of other serious illness such as heart, liver and kidney disease.
  • While you may currently have an undetectable viral load (and so no risk of passing HIV on to a sexual partner), your viral load is almost certain to rise if you take a treatment break. If condoms or PrEP are not used, you could pass HIV on to a sexual partner.
  • Though many people regain lost CD4 cells and experience a fall in viral load when they restart treatment, these may not fully return to the levels seen before the interruption.
  • Some people experience flu-like symptoms during an increase in viral load after taking a break from treatment.
  • There is a risk of drug resistance developing, particularly if stopping treatment is not done carefully, working with a doctor.
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