Laboratory Testing for Patients Taking Isotretinoin for Acne: Insights from Jonathan Weiss, MD

With a recent publication assessing the frequency of lab monitoring for patients with acne being treated with isotretinoin, AARS President Elect Jonathan Weiss, MD, FAAD, weighs in on the latest expert thinking. He also compares the current publication to the Guidelines of Care for Acne from the American Academy of Dermatology. 

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Transcript

This transcript provided as a courtesy. It has not been reviewed/edited for accuracy.

This is Hot Topics from the American Acne and Rosacea Society. We're glad you've joined us. Isotretinoin has been used to treat acne for four decades, and clinicians are still fine-tuning their approach to its use. In this episode, AARS President-elect Dr. Jonathan Weiss, addresses the recent publication Re-evaluating the Necessity of Routine Laboratory Monitoring during Isotretinoin Therapy for Acne.

Dr. Weiss, who is on staff at Georgia Dermatology Partners and Gwinnett Clinical Research Center in suburban Atlanta, is an adjunct assistant clinical professor of dermatology at Emory University School of Medicine. He lectures regularly at national meetings and is a past president of the Atlanta Association of Dermatology and Dermatologic Surgery and the Georgia Society of Dermatology and Dermatologic Surgery. He starts us off with an overview of the recent publication.

Jonathan Weiss:

The study by Zhu et al, or the letter by Zhu et al is an interesting jumping off point to discuss a topic that's become rather discussed in the literature and in conferences over the past few years, and that is what is the right amount of frequency in which to look at lab tests in isotretinoin patients?

Isotretinoin is a drug that initially people were checking lab tests every month, and quite honestly, what we found is that's way too frequently and they have made suggestions over time. Several authors have made suggestions over time is based on retrospective studies and this study by Zhu et al, or this letter by Zhu et al, what they did was they reviewed three retrospective studies. They reviewed one systematic review and a recent Delphi publication in which a group of experts got together and traded around questionnaires and tried to come up with a best answer for how often should we check lab tests in isotretinoin.

What they came up with as their conclusion, which is the majority conclusion of these other studies at this point, is that you should check lab tested baseline that include triglycerides and ALT, alanine aminotransferase, a liver function test, and that should be done right at baseline or within the month of baseline and then at peak dosage.

What I have a problem with that is I think many of us who have been prescribing isotretinoin for a long time have found that you can see increased triglycerides right at that first visit after initiating the dosage, which isn't peak dosage. So I question whether peak dosage is the answer or whether we should be doing that right after the first dosage and then at peak dosage. There's obviously no clear answer on that, but most people feel that the elevations you see in triglycerides almost all the time are not significant enough to cause medical morbidity. So it may be fine just to wait until peak dosage and that seems to be the justification for these recommendations.

Speaker 1:

Dr. Weiss is a co-author of the 2024 Acne Treatment Guidelines published in the Journal of the American Academy of Dermatology. How does he compare the guideline recommendations to this publication's conclusions?

Jonathan Weiss:

I feel like our recommendations were a little bit looser in the current acne guidelines from the American Academy of Dermatology that were just published in 2024. We did say that you should absolutely check triglycerides at or near baseline prior to the starting isotretinoin and then check them again at peak dosage. We also said that for alanine aminotransferase. What we didn't address was people who want to check them more frequently. We left it open that if people feel comfortable checking more frequently, they should. People with risk factors, people who had lab abnormalities, and that is I think, common sense, that if you pick up an abnormality in any of these lab values at baseline or at peak dosage, you should definitely keep an eye on them throughout the course of isotretinoin.

The Delphi study was interesting because they also had recommendations on what shouldn't be tested, and they recommended not testing for bilirubin, gamma-glutamyl transferase or GGT. Part of our recommendations in the acne guidelines in the Journal of the American Academy of Dermatology was to not bother checking a CBC, and that seems to be universal. We always checked complete blood counts, and it seems like now that is off the table, that those don't need to be checked.

Speaker 1:

With more than 40 years of use of isotretinoin, what has prompted review of testing requirements and what do we still need to learn?

Jonathan Weiss:

So why question this now when isotretinoin has been around for 30 to 40 years? And that's a very good question, reasonable question. I think the most important issue to understand is these are guidelines. They're not the law and anybody can and should do anything that they feel comfortable with, as long as it can be considered practicing good medicine and in the interest of a patient.

People were checking lab tests monthly throughout the eighties and probably the early nineties. At some point, many of us realized that wasn't necessary, and we have been checking lab tests very similarly to what these guidelines are, probably checking more of them, checking a complete hepatic profile, an entire lipid profile, and the CBC. What these guidelines do is they hone that down, they trim that down to tell you, you really don't need that CBC. That's not telling us anything, that you don't need to check an entire liver profile. You can check the one test and it doesn't need to be too sensitive a test because the GGT is such a sensitive test that it picks up inconsequential liver abnormalities. And you probably don't need the cholesterol along with the triglycerides or any of the subcomponents of cholesterol like LDL, HDL that come in a whole lipid profile.

So some of this is a medical economic issue where we don't need the wastage and we get just as much pertinent information out of two tests as we were getting from 10 to 20 tests. Whether or not we really need a study to determine the proper timing and number of tests to get from our isotretinoin patients is probably overkill, but it wouldn't be a bad thing for someone who has a lot of these patients or a consortium or the people who did the Delphi analysis or a group of us who are very interested to pool our results and see what we are doing over a number of years, say eight to 10 years, and see if it really makes a difference.

The problem will be if we are all only checking two tests, we don't know what we're missing, and so we go back to the problem of are we over testing? So I think that we have a pretty good idea based on 40 years of experience, and I think the recommendations that are out there to check baseline triglycerides, baseline ALT, and then at peak dosage, are the minimum that should be done. I think if someone wants to do them prior to peak dosage, that's fine. Then I think that people absolutely need to follow patients a little more closely who may have abnormalities in those tests along the way.

Speaker 1:

Thank you for joining us for this edition of Hot Topics from the American Acne and Rosacea Society. And special thanks to our guest, Dr. Jonathan Weiss. You can get updates on research and acne, rosacea and hidradenitis suppurativa in the semi-monthly Hot Topics Newsletter. The Hot Topics Newsletter is an AARS member benefit delivered to your email inbox. Get more information online at acneandrosacea.org.