How would I know if my drugs have stopped working?

You and your provider will need to keep an eye on your viral load and CD4 cell counts upon starting a treatment regimen and over the months and years you continue to take it. If any of the following occur, it might be possible that your drugs aren't working correctly:

	If your viral load is not lower than 400 after 24 weeks (six months) of starting therapy. An early way to tell if a drug regimen is being effective is to look for a 90% drop in viral load between 2 to 8 weeks after starting therapy. For example, if your viral load starts off at 50,000 and drops to 5,000 after 8 weeks, chances are good that your viral load will be less than 400 after six months of treatment.
	If your viral load is not lower than 50 ("undetectable") after 48 weeks (almost a year) of starting therapy. Undetectable does not mean zero -- it means that your viral load is less than the minimum amount of virus the test can detect. Today's more sensitive tests can measure 50 copies/mL or above, so undetectable means "less than 50". There are tests in existence that can detect HIV when there are less than 50 copies present, but they are commonly used for research purposes.
	If an undetectable viral load is detectable again. Some experts believe that a viral load that goes from being undetectable to detectable is a possible sign of treatment failure. But the results of one viral load test showing this jump is nothing to panic about. You should repeat the test—it may simply be an error or nothing more than a temporary "blip." If a second test confirms the results of the first test, it might be time to alter your regimen. If the blip is less than 400 copies, and only occurs once, this is not usually something to worry about. If virus is over 400 copies, however, or detectable on two tests in a row, this might be a sign that treatment is no longer working.
	If your CD4 cells do not improve while on combination therapy, regardless of viral load. No, it certainly is not only about viral load. The goal is to keep viral load low and the CD4 cell count high. A CD4 cell count should improve, on average, by 150 during the first year of treatment. If you started therapy with a low CD4 cell count, it could take more than a year to see your CD4 cell count improve by this much. You and your provider might want to consider altering your drug combination if your CD4 cell count does not improve by at least 25 to 50 during the first year of treatment. And if your CD4 cell count continues to fall while you are on treatment, changing your medications will likely be necessary.

Search for news stories about this topic