Drug resistance and switching to gain back control

[randym431]

I dont have this problem, but I always play "what if". So I wondered if those that developed drug resistance on meds, switched to a new med formula and regained undetectable again? And stayed that way since?
Or, as I wonder, if resistance does start, is it a down hill slope? That is, new drug combos working for a while then also failing? Is that the way it usually goes once resistance sets in?

[allanq]

I think a lot of the time resistance starts because the regimen didn't include three effective drugs (from at least two different classes) in the first place. In the old days (like 12 years ago), when a regimen started to fail it was very common to just add or substitute one new drug. This would give good results for a few months, and then resistance would inevitably set in again.

This is why it is important to have a genotype done before starting a new regimen to rule out any drug that you are already resistant to. Adding one new drug to a failing regimen is like being on just one drug.

There are a number of people on these forums who have been on the same regimen for many years and continue to have undetectable viral load. I may be wrong on this, but I don't think it's inevitable that an effective drug regimen will fail.

Allan