2-Drug Regimen Shows Benefit in Treatment of HIV

In an interview with Pharmacy Times® at the American Society of Health-System Pharmacists Midyear Meetings and Exhibition, Dena Behm Dillon, PharmD, AAHIVP, HIV clinical pharmacy specialist at the University of Iowa Health Care, discusses 2-drug regimens for individuals living with HIV.

Q: What are the optimal treatment approaches for individuals with HIV and what elements guide that treatment plan?

Dena Dillon: The most important is to individualize the treatment to the patient. So traditionally, there have been treatment regimen have included at least 3 drugs from at least 2 different classes. Recently, the guidelines for initial treatment of naive patients who haven't been on treatment before include: an integrase inhibitor along with 2 nukes. Recently, another option has been added to use a two-drug regimen for patients who are naive using dolutegravir with lamivudine.

As far as individualizing it, I like to have a discussion with the patient, sit down with them and talk and find out what their priorities are what's important to them. I look at both patient factors around the patient and factors around the regimen. For patient factors, I look at what their viral load is, and their CD4 count. Some regimens we don't want to use if their viral load is too high or their CD4 is too low. I also look at coinfection. If they have hepatitis B, hepatitis C or tuberculosis that can affect what treatment we choose. I look at their pregnancy if they're pregnant, or if they're planning to become pregnant, that will affect the treatment options, their ability to adhere, other medications they take including a lot of over-the-counter products that may interact with our treatments, and also other comorbid conditions, such as cardiovascular disease, renal disease, bone risk, hyperlipidemia, psychiatric illness, neurologic disease, or substance use disorders. As far as regimen factors, I look at what is the genetic barrier to resistance, the tolerability, the simplicity of for adherence, drug interactions, long-term toxicity, side effects, and cost their custom formulary issues that may affect our treatment choices. We look at convenient such as pill burden frequency administration, whether there are food requirements, whether the regimen is available in a single tablet, combination pill, or long acting injectables.

Q: What is the difference between 2-drug and 3-drug regimens?

Dena Dillon: The 2-drug regimens expose patients to 1 fewer medicine than 3 drug regimens, and that may lessen side effects over the long term.

Q: What are some of the benefits to 2-drug regimens?

Dena Dillon: There are 5 key benefits, so tolerability is one. With fewer drugs, we have better tolerability, less toxicity, lower costs can be usually the case, smaller pill burden sometimes Although we do have quite a few single tablet regimens now with 3 drugs and quality of life can be improved, sometimes with 2-drug regimens.

Q: What approach should pharmacists use to establish safety and appropriateness of 2-drug regimens?

Dena Dillon: Pharmacists should review the key studies about these drugs, and also the guidelines have a lot of useful information. We use the DHHS guidelines.

Q: Any closing thougths?

Dena Dillon: When I meet with a patient, there are several things that I discussed. Start out with goals of therapy, why are we even doing this, and these things are both for treatment and prevention when I'm meeting with patients, I also discuss the expected duration. So for treatment, it's going to be lifelong. For prevention, it can be just while they're in a higher risk of acquisition part of their life, so I make sure they know it doesn't have to be lifelong for prevention. We talk about adverse effects and how to avoid them.

With both treatment and prevention, I discussed drug interactions and really dig deeply into what medications they're taking. For both treatment and prevention, one of my favorite things to talk about even at cocktail parties is “u equals u.” So basically, the undetectable equals untransmissible, the CDC says if somebody's viral load is less than 200 for at least 6 months, it can't be spread through sex. This is a big advancement in treatment and as another way of prevention through treatment. I also like to tell people on prevention about that to help decrease the stigma, so they're not afraid of having a relationship of someone who's living with HIV.

I also talk about the importance if they're not on, some people are not on a single tablet regimen. I make sure they know it's really important to take either the whole regimen, or none of it. They never want to take a partial regimen because that can lead to resistance. I talk about especially with young people, how to get refills, a lot of people don't really know how to do that and that kind of the practical parts, the physician never thinks to talk about that. I talk with both treatment and prevention on how to stop if needed. If someone's on treatment, I make sure they know ahead of time when they're starting, if you're ever going to run out of the medicine, it's very important to not try to space out your doses to make it last longer. You take it every day till you run out, and then you stop, there's really key for the patients to know.

With their own prevention, I talked about this doesn't have to be lifelong, and some people go off and on it depending on different periods in their life, but it's really, really important what's prevention that they get another negative HIV test within a week before restarting along with a clinical assessment of symptoms of acute infection and exposures and such.

I also talked about how to handle missed doses, both for treatment and prevention. With prep, I'll talk about how long it's going to take until this gets active levels and different tissues depending on what type of activity they're having. I talked about condom use. The guidelines recommend that we counseled people to use them because prep isn't 100% effective, and it doesn't prevent other infections such as gonorrhea, chlamydia, syphilis, but it's really a personal choice between the patient and their partner, but the guidelines do recommend using them.