Undetectable by six months. This prevents drug resistance and allows the drugs to work longer. They differ slightly from recent International AIDS Society guidelines created only by doctors. If your regimen is failing, a drug-resistance test may help you determine why a given drug regimen is failing and help you select an alternative regimen. If absorption appears normal and a person is adhering to the regimen, change in therapy is warranted.
Viral load increases threefold or more above the lowest measurement.
CD4 T-cell count continues to fall. Clinical symptoms of HIV disease develop or get worse. Change at least two drugs in your regimen. Ideally, a new regimen should include at least two new drugs that you ve never taken before. If a person is clinically stable, has a detectable viral load, and possesses no good options for changing therapy, it may be best to delay changing therapy in the hope that better drugs will be available in the future.