Taking your HIV treatment in the correct doses, at the right time, observing any food restrictions and avoiding interactions will reduce the risk of resistance developing.

Before you start HIV treatment for the first time, or change treatment because your viral load is detectable, you should have a resistance test. There’s more information on these tests later.

The results of a resistance test will help you and your doctor to choose the combination of drugs that is likely to be most effective against your HIV.

It’s important to be honest with yourself and your doctor about the way you live your life. If it’s probable or likely that you won’t take your HIV treatment properly, then it’s important that your doctor knows this. This will allow your doctor to prescribe a combination of anti-HIV drugs that has a lower risk of resistance. For example, HIV treatment that is based on a boosted protease inhibitor has a lower risk of resistance than treatment that is based on an NNRTI.

The aim of HIV treatment is an undetectable viral load. If you have an undetectable viral load, your HIV cannot become resistant to the anti-HIV drugs that you are taking. However, resistance can develop if your viral load becomes detectable and you continue to take anti-HIV drugs. You can find out more about viral load in NAM’s booklet, CD4, Viral Load & Other Tests.

If your viral load is still detectable six months after starting HIV treatment, or falls to undetectable levels and then becomes detectable again in two consecutive tests, you should change HIV treatment.

Changing HIV treatment promptly can reduce the risk of drug resistance.

But before you change treatment, you should have a resistance test to help select the most effective combination of anti-HIV drugs. If you are changing HIV treatment because of resistance, it’s very likely that you will need to start a new combination of drugs.

Some important new anti-HIV drugs have become available for people who have drug-resistant HIV. The NNRTI etravirine (Intelence) can work well in most people with resistance to the other NNRTIs. Another important drug is the boosted protease inhibitor darunavir (Prezista).

Important new classes of anti-HIV drugs have been developed. These include the integrase inhibitor raltegravir (Isentress), the CCR5 inhibitor maraviroc (Celsentri) and the fusion inhibitor T-20 (enfuvirtide, Fuzeon).

For more information on these drugs and your treatment options if you have drug-resistant virus, see the NAM booklet, Anti-HIV Drugs.