A detectable but low (up to 5,000) viral load and limited treatment use (e.g., failing your first, or second, treatment regimen): The goal here is to bring your viral load back down to undetectable without completely changing your regimen. One option to consider is "boosting" your current regimen by adding another drug. For example, if you are taking a protease inhibitor (PI), adding a low dose of Norvir® (ritonavir) will increase the amount of the PI in your bloodstream, thereby making it more effective against the virus (this works for all PIs with the exception of Viracept® [nelfinavir]). Another possible option is "intensification" of your regimen, perhaps adding another nucleoside reverse transcriptase inhibitor (NRTI) to increase the number of active HIV drugs being used. There is also the possibility of using drug-resistance testing to determine which drugs are no longer working so that you can switch them for more active options. If you decide to do nothing, watching viral load closely should be a priority; the higher the viral load gets, the more resistant HIV can become to the medications being used.

No resistance identified using drug-resistance testing: First it's important to consider when blood for the drug-resistance test was drawn. For the most accurate results, drug-resistance testing should be performed while the person is still taking treatment (and has a detectable viral load) or within four weeks after the treatment regimen was stopped. If the test was performed long after treatment was stopped, it may be necessary to restart treatment and repeat the test after two to four weeks. A detectable viral load while on therapy, without evidence of drug-resistance mutations, can also mean poor adherence.

An undetectable viral load but poor CD4 cell count improvements: Some people see their viral loads decrease to undetectable levels while on treatment, but experience a further decrease or limited increase in their CD4 cell count. If this occurs, the first step should be to rule out other problems that can cause immune suppression, such as other infections or drug toxicity. Some HIV drugs, such as Viread (tenofovir) and Videx/Videx EC (didanosine) taken together, have been shown to cause CD4 cell count problems. Another possible solution might be to intensify treatment with another HIV drug or, perhaps, consider the use of an immune-based therapy such as Proleukin® (interleukin-2).

More extensive prior treatment experience: For people who have tried and failed several HIV drugs in the past, making switch decisions can be a tricky process. Drug-resistance testing is a key tool to use in this situation. If drug-resistance testing determines that a person's virus is still sensitive to at least two available HIV drugs, using those drugs should be a priority, with the goal of pushing viral load to undetectable. The DHHS guidelines do not recommend adding on a single drug that a person's virus is sensitive to, as HIV will probably develop rapid resistance to that drug as well. With new drugs becoming available and entering clinical trials on a regular basis, it may be best to wait until it can be combined with a newer drug that the virus may also be sensitive to. Additional recommendations for people with few remaining HIV treatment options are provided in the next section.