For generally ideally within a month prior to the start of treatment, and a second time at peak dose.
Other tests such as complete blood cell counts and basic metabolic panels as well as specific laboratory tests such as LDL and HDL cholesterol should not be routinely monitored.
Those are key conclusions from a Delphi consensus study that included 22 acne experts from five continents and was published in JAMA Dermatology.
“Our results apply findings from recent literature and are in accordance with recent studies that have recommended against excessive laboratory monitoring,” senior corresponding author Arash Mostaghimi, MD, MPA, MPH, and coauthors wrote. “For instance, several studies in both teenagers and adults have shown that routine complete blood cell count laboratory tests are unnecessary without suspicion of an underlying abnormality and that rare abnormalities, if present, either resolved or remained stable without clinical impact on treatment. Likewise, liver function tests and lipid panels ordered at baseline and after 2 months of therapy were deemed sufficient if the clinical context and results do not suggest potential abnormalities.”
The authors also noted that, while published acne management guidelines exist, such as the American Academy of Dermatology work group guidelines and the National Institute for Health and Care Excellence guideline, “the specific recommendations surrounding laboratory monitoring frequency are nonstandardized and often nonspecific.”
To establish a consensus for isotretinoin laboratory monitoring, Dr. Mostaghimi, of the department of dermatology at Brigham and Women’s Hospital, Boston, and colleagues used a Delphi process to administer four rounds of electronic surveys to 22 board-certified dermatologists between 2021 and 2022. The primary outcome measured was whether participants could reach consensus on key isotretinoin lab monitoring parameters. Responses that failed to reach a threshold of 70% indicated no consensus.
The surveyed dermatologists had been in practice for a mean of 23.7 years, 54.5% were female, 54.5% practiced in an academic setting, and 63.9% were based in North America. They reached consensus for checking ALT within a month prior to initiation (89.5%) and at peak dose (89.5%), but not checking monthly (76.2%) or after completing treatment (73.7%). They also reached consensus on checking triglycerides within a month prior to initiation (89.5%) and at peak dose (78.9%) but not to check monthly (84.2%) or after completing treatment (73.7%).
Meanwhile, consensus was achieved for not checking complete blood cell count or basic metabolic panel parameters at any point during isotretinoin treatment (all > 70%), as well as not checking gamma-glutamyl transferase (78.9%), bilirubin (81.0%), albumin (72.7%), total protein (72.7%), LDL cholesterol (73.7%), HDL cholesterol (73.7%), or C-reactive protein (77.3%).
“Additional research is required to determine best practices for laboratory measures that did not reach consensus,” the authors wrote. The study results “are intended to guide appropriate clinical decision-making,” they added. “Although our recommendations cannot replace clinical judgment based on the unique circumstances of individual patients, we believe they provide a framework for management of a typical, otherwise healthy patient being treated with isotretinoin for acne. More routine monitoring, or reduced monitoring, should be considered on a case-by-case basis accounting for the unique medical history, circumstances, and baseline abnormalities, if present, of each patient.”
“Practicing dermatologists, including myself, routinely check blood laboratory values during isotretinoin treatment,” said Lawrence J. Green, MD, clinical professor of dermatology at George Washington University, Washington, who was asked to comment on the study. “Even though just a small number of U.S.-based and international acne researchers were involved in this Delphi consensus statement, this article still makes us practicing clinicians feel more comfortable in checking fewer lab chemistries and also less frequently checking labs when we use isotretinoin.
“That said, I don’t think most of us are ready, because of legal reasons, to do that infrequent monitoring” during isotretinoin therapy, Dr. Green added. “I think most dermatologists do not routinely perform CBCs anymore, but we still feel obligated to check triglycerides and liver function more frequently” than recommended in the new study.
Dr. Mostaghimi reported receiving grants and personal fees from Pfizer, personal fees from Eli Lilly, personal fees and licensing from Concert, personal fees from Bioniz, holds equity and advisory board membership from Hims & Hers and Figure 1, personal fees from Digital Diagnostics, and personal fees from AbbVie outside the submitted work. Other authors reported serving as an adviser, a speaker consultant, investigator, and/or board member, or having received honoraria from different pharmaceutical companies; several authors had no disclosures. Dr. Green disclosed that he is a speaker, consultant, or investigator for numerous pharmaceutical companies.