How often will I have to visit the clinic?

Some trials will require frequent clinic visits, especially during the first few weeks. It is essential for the smooth running of the trial and the accuracy of the trial results that you are able to attend on the days and at the times you are asked to. Make sure that the schedule for clinic visits is explained to you, and if you think it isn't going to be manageable, explain this to your doctor or the trial nurse.

Some clinics or trials are able to offer financial help with childcare and transport costs. Ask whether these are available for the trial you are thinking of joining.

What will happen at these visits?

Trial monitoring visits will normally include taking blood for viral load tests, CD4 counts and other tests intended to monitor the effectiveness and safety of your treatment. You will also see your doctor, and have the opportunity to report any side-effects or problems you are having with taking the medicine. It is especially important to report problems of this sort, because the information you can provide during the trial will help people who take the drug in the future.

Occasionally, a study may require a test such as a bronchoscopy or endoscopy (insertion of an optical tube down the throat and into the lungs or digestive tract), or a lymph tissue biopsy (removal of a microscopic portion of tissue from the lymph nodes or tonsils), or a lumbar puncture (insertion of a needle into the spine to withdraw spinal fluid). These investigations are rare, but ask at the beginning of the study whether any special procedures will have to be carried out at any time.

When will I get the results of blood tests?

Some trial protocols will permit you to receive the results of viral load tests and CD4 counts in 'real time' – within a few days or weeks of the test. This will allow you to discuss options with your doctor if your viral load appears to be increasing, or has not been suppressed satisfactorily.

However, other studies will not provide this information to patients. It will be left up to your doctor to decide when you should come off the trial medication if you show signs of a poor response to your current treatment. It's up to you to decide whether you want to take part in this kind of trial.

What other medications or drugs can I take while on this trial?

The trial protocol will usually specify certain drugs that should not be taken in case they confuse the outcomes of the trial. To be ethical, trials must allow participants to receive the current standard of care.  However, many drugs used in HIV therapy have interactions with other drugs. In the case of experimental drugs, ask what is already known about interactions. Ask for a full list of the medicines (including over-the-counter medicines for hay fever, headache or other everyday complaints) which should be avoided.

Many trials also exclude current injecting drug users. This is partly because researchers fear that people who inject drugs will not adhere to the study medication. It is also because there is a risk that opiates, amphetamines, barbiturates, cocaine or impurities in injectable forms of these drugs may lead to harmful interactions with the study medication.

Are there any restrictions relating to birth control or pregnancy?

Many trials require women who could become pregnant to be using contraception. However, some may not allow the use of the contraceptive pill in case there is an interaction with the study medication. Find out what sort of contraception is allowed or required. Most trials exclude pregnant and breastfeeding women. Find out what you would have to do if you thought that you had become pregnant while in the trial, and what is known about the potential effects of the study medication on the unborn child.

What happens if my condition worsens?

Many trials require you to leave the trial if your condition worsens beyond a
pre-defined point. For example, if your viral load does not fall below the limit of detection after 24 weeks on the drug, or if your viral load rises above the limit of detection after being undetectable, you may have to come off the trial. Some trials guarantee that people who have been receiving a placebo will be switched over to receive the genuine trial drug if their condition deteriorates. Check what the procedure would be in your study.

How long will the study last?

In the protocol, the researchers usually give an estimate of how long the trial will last. While some trials last only a few weeks, others can go on for years. In many large trials, a special group of independent experts and lay people, called a Data and Safety Monitoring Committee, checks regularly on the results of the trial while it is taking place. If they find that one group of patients is doing much better than the other, they can recommend that the trial is stopped earlier than planned so that the better treatment can be offered to all the participants. They can also recommend that a trial should be stopped if many trial participants develop serious side-effects.

Some trials collect information on the participants' health even after the trial has stopped. If the results are favourable, some trials will offer a supply of the drug to all participants in the study until it becomes available through other access programmes or is licensed for doctors to prescribe.

How will this trial affect my future options?

One of the most important things that may be studied in a trial is how resistance to the trial drug develops. Developing drug resistance is one of the risks of participating in a clinical trial, but it is a potential risk of many forms of antiretroviral treatment. In a clinical trial, clear safeguards should be built into the design of the trial to minimise the risk that you will develop resistance.

These safeguards are based on current knowledge about the best ways to avoid resistance. For example, your treatment may be changed if your viral load increases above the limit of detection after a period of suppression.

Participation in a trial of one drug can also affect your opportunity to join future trials, whether or not you develop resistance to the drug. This is because it is often preferable to test new drugs in people who have absolutely no risk of cross-resistance, in order to get clear results. So if you have previously taken a protease inhibitor, you may be excluded from a future protease inhibitor trial because the researchers want to test the drug in protease inhibitor 'naive' people – those people who have never taken one.

Will I be informed of the trial's results when it ends?

Sadly, many researchers and drug companies have not been good at communicating trial results to the people who took part. Many people may find it unacceptable that they are not informed of the practical outcome of their time in the trial, or only stumble across the results by chance in (often distorted) newspaper accounts. Ask how the researchers will ensure that you are told the trial results.

If for any reason you don't approve of the trial design, it is important to tell the researchers. For instance, if you believe that joining the trial is the only way of getting an experimental treatment, you may decide that your interests are best served by joining the trial even though you are unable or unwilling to comply too closely with the rules. However, the researchers may be able to suggest other options if you are frank with them.

How will other drugs taken during the trial be chosen?

An increasing number of trials are aimed at people who already have experience of previous anti-HIV treatment, and these people may have resistance to some drugs. Unless the trial is specifically designed to recruit only those people who have taken particular drugs in the past, you should be offered the opportunity to choose the drugs you take alongside the trial drug in the way now considered to be the standard of care – by resistance testing.

Resistance tests are now recommended in the UK for people newly diagnosed with HIV, people who are about to start their first HIV treatment combination, and people who are changing treatment. Every clinical trial into and experimental HIV drug should therefore offer resistance tests.

Would I be advised to start treatment now even if this trial wasn’t taking place?

Trials which recruit people with no previous treatment experience fall into two categories:

• Those for people infected within the past six months (primary infection).
• Those for people who have been infected for several years (chronic infection).

If you are asked to join a primary infection study, you should think carefully about whether you want the commitment of long-term treatment at a time when you
are still adjusting to living with HIV.

Beginning treatment during primary infection means that you would be starting treatment 5-7 years before current thinking suggests you need it. Trials are trying to answer questions like: will a short period of treatment just after infection influence the long term course of HIV infection? Is it better to continue that treatment indefinitely, or should it be stopped after a year or two?

At the moment the answers to these questions are unknown, and that is why clinical trials are taking place. If you join one of these studies, you will be helping to answer very important questions.

Joining a trial after you have been HIV-positive for a number of years will have different implications depending on how long you have known that you are HIV-positive, and your overall state of health. It may be very difficult to deal with taking part in a study if you have been recently diagnosed, because you are still getting used to knowing about your HIV status and building a relationship with your clinic. You should not be made to feel that you are expected to join a study just because your doctor has suggested that you might consider it.

There is also a danger that you may be encouraged to start treatment earlier than might be necessary, so you end up taking medication for longer than if you had decided to wait.