Let's face it. No drug—or combination of drugs—is going to work for everyone, or work forever. Studies have pretty much confirmed that for every two people who are able to stay on a selected treatment regimen for a long period of time, there is another person who is unable to keep their viral load down, CD4 cells up, or tolerate the side effects while on their first HIV drug combination of choice.
The good news is that treatment options to choose from have greatly expanded in recent years. During the early years of combination HIV treatment, the take-home message was that the first regimen used was the "best bet" in terms of keeping viral load undetectable and CD4 cells high. If the first regimen stopped working properly, due to the emergence of drug resistance, there simply wasn't any guarantee that subsequent drug combinations would provide long-lasting results . Today this is no longer the case. With greater understanding of drug resistance and drug-resistance testing, along with the approval of drugs specifically designed to treat drug-resistant virus, maintaining control of HIV for long periods of time is entirely possible.
Like figuring out when to start therapy and what drugs to start with, deciding when to switch therapies and what drugs to switch to is a complex process. The following questions and answers (Q&A) are intended to help you figure out why treatment switches are necessary, when they are likely needed, and what can be done if and when the time comes.