We’ve made great strides in antiretroviral therapy (ART) to treat human immunodeficiency virus (HIV) since I first started my career in 1998. In fact, there are over 30 different medications available that can keep your virus in check. However, treatment options are still limited because once you stop taking a medication, or even miss just one day of treatment, the virus can mutate and become resistant to that specific treatment and it will never work again to keep your virus from replicating. For that reason, we will only switch medications as a last resort -- and it’s pretty rare that the first-line regiment won’t successfully control your viral load. When we do switch to a new regimen, it’s because you are experiencing intolerable side effects like nausea, fatigue and/or diarrhea; your medication is reacting negatively with another medication you are taking; or if it is simply not working to control your viral load. The process When selecting a new treatment, we’ll take into account your treatment history as well as resistance testing to determine the most effective combination of drugs. This is done with a genotypic assay resistance test, which looks for the genetic material of the HIV in your blood to determine which drugs your virus is resistant to, or a phenotypic assay, which evaluates how the virus responds to medication in a controlled environment. We will likely change each drug in your treatment cocktail, using at least three medications from two or more drug classes. After proper testing and evaluation, your new treatment should put you right back on track to keep your viral load down and your CD4 T cell count high. Whether your medication fails to control your viral load after one month of taking it, or just stops working after ten years, it’s never too late to find an effective therapy and get your virus back under control. We’ll check your viral load a month after you begin your new therapy, and by then, your numbers should start decreasing if the new treatment is effective. What to expect Just like your first treatment, it’s important to make sure you’re taking your medication every day because when the virus is not fully controlled by medication, the HIV replicates extremely rapidly. During replication, new forms or “mutations” of the virus are created and these mutations may not respond to the antiretroviral regimen you’re currently on. And that means your virus will grow resistant to the treatment you’ve just switched to and begin freely replicating in your blood. If we have to keep switching medications, we’ll eventually run out of options and have to put you on an older regimen with much harsher side effects. Speaking of side effects, we try not to hastily switch medications just because of them. In my experience, most people will have few or no side effects with HIV treatment. You may experience an initial upset stomach, fatigue, aches and pains and other various minor side effects; however, these should go away within a few weeks as your body adjusts to the medication. With the proper consideration of past side effects, treatment history, and resistance testing -- along with the various medication options now available, there is no reason you will not be able to live a normal, healthy life as someone who never switched treatment regimens.