What is the name of the drug?

All medications have at least two names: a generic one, such as zidovudine, and a trade name, such as Retrovir, which is used to market the drug and which appears prominently on the packaging. Some are also referred to using an abbreviation of their chemical name, e.g. AZT. It is useful to be familiar with all of these names.

What does it look like?

If you are trying to decide what medication to take, it may be useful to see the tablets. Some people have more difficulty swallowing large pills than others. To compare all antiretroviral drugs licensed in the European Union, see NAM's drug chart. The chart contains illustrations of the drugs, as well as information on drug doses, formulations, pill burdens, main side-effects and food restrictions.

How and when do I take it?

All entries in the A-Z of drugs describe how frequently a drug should be taken. Most antiretroviral drugs are taken one to three times per day. Complete once-daily regimens are now available.

In addition, some drugs should be taken with food while others should be taken on an empty stomach. With most antiretroviral drugs today, there are no restrictions regarding specific foods to avoid. A booklet in NAM’s Information series for HIV-positive people, called Nutrition, gives details of interactions between anti-HIV drugs and food.

What side-effects might I experience?

Most drugs will have side-effects, especially during the first few weeks of treatment. If you know what to expect you may find them easier to deal with, or you may decide that you will find a particular type of side-effect particularly bothersome, and therefore decide to choose other drugs.

The most common early side-effects tend to be:

• Nausea
• Vomiting
• Diarrhoea
• Headache
• Fatigue
• Skin rash.

Other side-effects may emerge later during the course of treatment, for example:

• Peripheral neuropathy (tingling in the hands and feet due to nerve damage)
• Body shape changes.

Some side-effects show up in laboratory blood tests, including:

• Liver toxicities (elevated liver enzymes)
• Elevated blood fats (cholesterol, triglycerides)
• Abnormal blood sugar or insulin levels
• Neutropenia (low levels of white blood cells needed to fight infections)
• Anaemia (low level of oxygen-carrying red blood cells).

Because anti-HIV drugs are only tested in a few thousand people before being licensed, there is a chance that rare side-effects will only become apparent after tens of thousands of people have taken the drug.

What can I do to relieve side-effects?

It is often possible to relieve side-effects by taking other medications that will not interfere with your anti-HIV therapy. For example, your doctor can prescribe anti-nausea drugs and painkillers can be used to relieve headaches. Some skin rashes can be relieved by anti-histamines. Elevated blood fat levels may be managed using lipid-lowering drugs. In some cases side-effects may be improved if a drug is taken with food. Another option with some drugs is to escalate the dose gradually.

Can I stop treatment if I can't stand the side-effects, or want a break?

It is best to consult with your doctor before making any changes to you antiretroviral therapy. Stopping treatment may allow you viral load to rise, and your CD4 cell count to start going down. Studies have shown that treatment interruptions can lead to disease progression. If you decrease your drug doses or stop taking only one drug in a regimen, there is a greater chance that HIV will become drug-resistant. If you need to stop treatment, it is probably better to discontinue all drugs. However, some drugs leave the body more slowly than others, which is another reason to speak to your doctor beforehand.

What do I do if I miss a dose, or take too much?

If you miss a single dose by a few hours, you should take the missed dose as soon as you can, and take the next dose at the usual time. However, if you miss the dose completely, and only realise this when you come to take the next dose, there is no additional benefit in taking a double dose. The occasional missed dose may not be problematic. However, missing doses regularly (for example, every weekend) will likely encourage the development of drug resistance.

Will anti-HIV drugs interact with other drugs?

Anti-HIV drugs, particularly protease inhibitors, interact with many other drugs, including prescription drugs, over-the-counter drugs, recreational drugs and herbal preparations. Drug interactions may cause serious side-effects. Furthermore, interactions may undermine the effectiveness of one or more drug. When considering a new drug, ask you doctor what is known about its interactions with drugs you are already taking. For details of drug interactions, see individual drug entries in A-Z of drugs.

Do I need to be careful about drinking or recreational drugs while on treatment?

Very few anti-HIV drugs are affected by alcohol, although the risk of pancreatitis or liver problems may be increased if you drink heavily, in the view of some doctors. Some recreational drugs do seem to interact with antiretroviral medications, which could lead to levels in the body that are too low (and therefore ineffective) or too high (causing more side-effects or overdose). See Drug interactions and pharmacokinetics for information about specific drugs. Remember also that you may find yourself missing doses if you are 'out of it' because of drug or alcohol use, and that this can cause treatment failure.

What if think I am pregnant or want to conceive?

If you are already on treatment, any potential adverse effects of drugs on the foetus are most likely to occur during the first 14 weeks of pregnancy. HIV transmission is more likely to occur during delivery, but may occur earlier in pregnancy. Specific drugs, including AZT (Retrovir) and nevirapine (Viramune) have been shown to reduce the risk of mother-to-child HIV transmission. Effective combination antiretroviral therapy using other drugs is also beneficial, since the risk is reduced when the mother has a low viral load.

Most anti-HIV drugs do not appear to cause birth defects or long-term problems in children exposed during pregnancy. However, efavirenz (Sustiva / Stocrin) should not be used by pregnant women since it can cause birth defects. If you are pregnant or want to conceive and are concerned about the risk posed by antiretroviral drugs, you should discuss the relative risks of staying on or coming off treatment with your doctor, since information on this question may change. See HIV treatment during pregnancy for more on this subject.

Do these drugs need to be refrigerated or kept in a special container?

Some drugs may deteriorate in hot conditions and so may require refrigeration, or may need to be stored in a cool place, out of direct sunlight. Other drugs may be affected by damp conditions, and may need to be kept in a container with a special dessicant (a substance which draws moisture out of the air). Your doctor or pharmacist will be able to provide advice on this.

Can I take my drugs on holiday?

The major difficulty with taking anti-HIV drugs on holiday is that they may draw to your HIV-positive status. However, the packaging for these drugs does not reveal that they are prescribed for the treatment of HIV, and a letter from your doctor which says that you are prescribed these specific drugs should provide sufficient cover. People who wish to enter the United States may have difficulty, however, since the country restricts entry for HIV-positive people.

If you are going to a hot climate, some drugs may be affected by the heat or humidity. Ask your doctor or pharmacists whether this is likely to be a problem with your specific drugs, and how to deal with it.

Alterations in time zones and eating schedules on long-haul flights may be more problematic. Although airlines recommend that you switch into the time zone of your destination as soon as the flight begins (in order to combat jet lag), this may be confusing if you are trying to stick to a schedule. If you are gone for less than five days, it will probably work out easier to stick to home time, but if you are away for longer, try to tailor your dosing times to the time zone of your destination as quickly as possible without missing doses. With most drugs, you have a couple of hours leeway either side of the 8-hour or 12-hour at which you are meant to take the drugs.

Can I drive a car or operate machinery while taking these drugs?

If any medication is causing severe fatigue, drowsiness, dizziness or loss of concentration, you should be very careful about driving or operating machinery. These have all been reported as early side-effects of some anti-retroviral drugs.

How can I get further information about this treatment?

A variety of sources can provide information about the drugs prescribed to you. At the very least, your doctor should provide a clear explanation of the issues discussed in this section, supported by written information to take home. Your pharmacist should know the answers to these questions. Most drugs include a patient information section in the package insert, and some drug companies have produced information booklets about their drugs.