Vietnam Hospital for Tropical Diseases
Most clinical trials test new therapies against existing treatments in order to find out which approach is better at treating a particular illness. Carefully controlled and scientifically rigorous, this sort of experiment enables doctors to know which is the most effective and appropriate treatment for their patients.
In reality, medicine can be more complicated. If a patient comes to their doctor with more than one complaint, for example, should the doctor treat one disease at a time or both at the same time? The treatments for the two conditions may interact, causing more problems than they solve. Or the cumulative effect of both treatments may mean the patient is more likely to suffer toxic side-effects. But if the doctor postpones treatment for one illness while treating the other, the patient’s life may be put at risk.
This is frequently the case for people who have an HIV infection. HIV doesn’t always cause symptoms but it does make people more susceptible to other infections and illnesses. So in a lot of cases, HIV infection is detected only when the person goes to their doctor with symptoms of another serious – often life-threatening – illness, such as tuberculosis. Should the doctor treat the tuberculosis first or both infections at the same time?
Current guidance from the World Health Organization (WHO) suggests antiretroviral therapy (ART), the best treatment for HIV/AIDS, should not be delayed for the treatment of other conditions. This advice is based on observational studies but a number of trials have recently been set up specifically to test when is the best time to start treating HIV infection in people with a concurrent illness.
Poster raising awareness of HIV services in Vietnam
In Vietnam, a Wellcome Trust-funded trial examined the effect of delaying ART for patients who came to the Hospital for Tropical Diseases in Ho Chi Minh City with HIV-associated tuberculous meningitis. A tuberculosis infection in the central nervous system, this illness accounts for 25 per cent of global HIV/AIDS deaths.
Out of 253 such patients enrolled in the randomized controlled trial, 127 were given ART alongside their tuberculosis treatment as soon as they were diagnosed. The other 126 were given placebos instead of ART for two months, at which point they began to receive ART as their tuberculosis treatment continued.
Looking at the numbers of patients who died within nine months of starting treatment, the results, published last month in ‘Clinical Infectious Diseases’, showed no significant difference in mortality between those who had ART immediately and those who had two months of placebo. However, they did reveal that those who received ART immediately were more likely to suffer serious side-effects such as hepatitis and neurological effects such as seizures.
Based on this evidence, the study’s authors suggest ART should be delayed for two months in these patients. To do so seems not to affect their risk of dying, but it does reduce the chance of adverse side-effects.
Does this mean the WHO guidelines are wrong? Well, as a commentary article accompanying the research paper says: “The question of the optimum timing clearly has more than one right answer.” In Ho Chi Minh City, most of the patients with HIV-associated tuberculous meningitis are young, male intravenous drug users. As a group, they are more likely to have other complications such as hepatitis B and hepatitis C infections as well as HIV. This may be the reason why they are particularly susceptible to liver problems when treated with several drugs at the same time.
In this situation, then, it is likely that ART should be delayed to give patients the best chance of overcoming the tuberculosis infection before treatment for HIV begins. However, in other settings, as similar trials elsewhere are finding, it is better to give ART alongside treatments for other conditions as soon as possible, as per the WHO guidance.
The overriding message is that this is not a ‘one size fits all’ situation: different settings and different population groups require different approaches. Wherever they are in the world, doctors need to apply the art as well as the science of medicine.
http://wellcometrust.wordpress.com/2011/07/12/the-art-of-timing/#more-5838
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