An Expert's Perspective on HIV Drug Resistance
Treatment for HIV has progressed so much since the 1980s that patients can now live a normal life.
But there isn't an easy fix with medication, and HIV drug resistance is one of the greatest challenges of treating the virus. Dr. Silvania Ng explains why.
1. Q: How has HIV treatment evolved and progressed since the 1980s?
A: In the 1980s and early 1990s, HIV was a very grim diagnosis. Treatment options were limited, and HIV almost certainly led to AIDS, and eventually, death. The first HIV drug, or antiretroviral treatment (ART), Zidovudine (AZT) was a nucleoside analog reverse-transcriptase inhibitor or (NRTI). While AZT was somewhat effective in keeping the virus from replicating, severe side effects and limited efficacy forced researchers to find a better solution. Researchers discovered that the virus was able to mutate, and become resistant to this single therapy.
The mid-1990s were the golden age of HIV medication. A new class of antiretrovirals, protease inhibitors (PIs), were more effective, and slightly better tolerated than AZT -- though they still came with their share of side effects. The greatest benefit of PIs though was that there were now enough HIV medications to allow for combination therapy, or treating the virus with multiple medications at once. That, researchers figured out, was key to keeping the virus from developing drug resistance. By the early 2000s, ART therapies were more effective and had fewer side effects, but patients were still having to take three pills a day -- which changed in 2006.
Today, the three drug regimens can be found in a single pill, making it easier for patients to adhere to their treatment plan. Now, as long as you take your ART every day as prescribed, you can expect to live a long and healthy life.
2. Q: What is HIV drug resistance?
A: Currently, there’s no way to completely eradicate HIV from your system, but successful ART will be able to keep the virus from replicating. In other words, the virus is still there, but is in a dormant state.
When left untreated, HIV replicates extremely rapidly, attacking CD4 cells in the process. Just as you would make mistakes if you were drawing the same symbol over and over again very quickly, HIV makes mistakes when copying itself. These mistakes, or mutations, can sometimes be resistant to HIV medications, allowing the virus to continue destroying your immune system.
You may have acquired drug resistance, meaning the HIV transmitted to you already contained drug resistant mutations, or you may develop drug resistance.
The most common way HIV develops drug resistance is if you don’t take your medication properly. If the virus notices an absence of drugs in your system, which it most definitely will, it will immediately begin to replicate. The worst part is, once your virus becomes resistant to the medication you’re on, that medication will never be effective again in treating your HIV.
3. Q: What are signs of HIV drug resistance?
A: Fevers, sweats and weight loss are visible physical signs that your HIV medication may have stopped working --
whether because your virus has developed drug resistance, or another reason. A test from your HIV provider will tell you for sure. Your blood work will show if your viral load, the amount of HIV in your system, is detectable -- and if it is indeed detectable when it previously wasn’t on your medication, then your virus has likely developed resistance to the medication you’ve been taking.
To find out whether your virus has mutated to cause the resistance, your doctor will most likely administer a genotype test. If the virus has indeed mutated, you’ll need to be switched to a medication that will work against the mutated version.
4. Q: What are treatment options after HIV drug resistance?
A: The good news is we have more treatment options for HIV now than ever before. The bad news? They’re not unlimited. However, if drug resistance is detected early, it’s usually easily managed by stopping the ineffective ART, and starting a new combination. Only in extremely rare cases will the virus be resistant to every type of available medication. This would only happen after several different ART regimens have failed. So, while we do have options if your virus develops resistance to your medication, it’s extremely important to take your medication every day -- because if your virus keeps developing resistance due to poor adherence, we’re eventually going to run out of options for you.
5. Q: How can HIV drug resistance be prevented?
A: The number one way to prevent HIV drug resistance is taking your medication every single day exactly as prescribed by your doctor. Since the virus replicates so mercilessly, you simply cannot forget or miss a dose. If you do happen to miss taking a pill, immediate communication with you doctor is critical. He or she will need to check your viral load and may have to start you on a new drug regimen as soon as possible.
Also, if another physician you’re seeing prescribes a medication for a different condition, or even changes the dose, make sure to relay that information to your HIV provider. While drug-drug interaction is rare, it is also a possible cause of treatment failure. And finally, never miss a doctor’s appointment -- monitoring the condition every three to six months is key to ensuring a long and healthy life.