Clinical trial: A type of research study that tests how well medical treatments work in people.
Drug class: A group of medications that work in the same way.
Drug interaction: A change in how a drug works when taken with another drug (drug-drug interaction) or with a specific food (food-drug interaction).
Drug resistance: When HIV mutates (changes form), causing one or more anti-HIV medications to be ineffective.
Drug-resistance testing: A blood test to identify which, if any, anti-HIV medications will not be effective against a person's specific strain of HIV. Drug-resistance testing is done using a sample of blood.
Regimen: A combination of three or more anti-HIV medications from at least two different drug classes.
Treatment adherence: Closely following an HIV treatment regimen -- taking the correct dose of each anti-HIV medication at the correct time and exactly as prescribed.
Viral load: The amount of HIV in the blood. One of the goals of antiretroviral therapy is to reduce viral load.
At some point, you may need to adjust or change your regimen. But before making any changes, it's important to understand why.
There are several reasons why a person may switch to another HIV regimen:
If you and your health care provider decide it's time to switch your treatment regimen, you will have many things to consider. For example, together you will review:
In general, a new treatment regimen should include two or more medications from two or more drug classes. If you are switching regimens, your new regimen may include anti-HIV medications that you have never used before.
If you have already taken many of the FDA-approved anti-HIV medications, your health care provider may recommend a new medication only available through a research study (clinical trial). To learn about participating in a research study, ask your health care provider or visit the Clinical Trials section of the AIDSinfo website at http://aidsinfo.nih.gov/clinicaltrials.
Before starting your new regimen, make a commitment to keep your medical appointments and take your anti-HIV medications exactly as prescribed. Talk to your health care provider about steps you can take to overcome any lifestyle or personal issues that can make adherence difficult. (See the "Treatment Adherence" and "Following an HIV Treatment Regimen" fact sheets.)
Be sure to ask your health care provider about possible side effects from your new anti-HIV medications. Also discuss potential drug interactions between the medications in your regimen and other medications, vitamins, nutritional supplements, and herbal products that you take or plan to take.
Contact an AIDSinfo health information specialist at 1-800-448-0440 or visit http://aidsinfo.nih.gov. See your health care provider for medical advice.
This information is based on the U.S. Department of Health and Human Services' Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents.