Although studies indicate that isotretinoin is a highly effective treatment for acne, laboratory monitoring during isotretinoin therapy is a common practice due to concerns about potential side-effects. With several studies over the past decade questing the value of this practice and some calling for reduced monitoring—which has the potential to decrease healthcare costs and patient discomfort from blood draws—John S. Barbieri, MD, MBA, and colleagues evaluated the clinical value of laboratory monitoring in recent years.

Evaluating the Practice

For a study published in the Journal of the American Academy of Dermatology, Dr. Barbieri and colleagues evaluated how often laboratory tests during isotretinoin therapy are abnormal, as well as monitoring patterns and changes over time. Subjects had at least one ICD-9 or -10 code for acne, at least one prescription for isotretinoin on or after the acne diagnosis date (first prescription was defined the index date), at least 6 months of continuous enrollment prior to the index date with no prescriptions for isotretinoin, and at least 1 year of continuous enrollment after the index date.

Laboratory values for triglycerides, total cholesterol, aspartate aminotransferase (AST), alanine aminotransferase (ALT), white blood cell count (WBC), and platelet count were identified for each patient and categorized as baseline or by month of therapy.

Key Findings

Dr. Barbieri notes that laboratory abnormalities were rare. “We found that lipid panel abnormalities were uncommon (<1%), but did occur,” he says. “Notably, these abnormalities tended to occur early in the course of therapy; checking lipid panesl once at peak dose may be sufficient to detect these abnormalities.” The study team also found that liver function testing abnormalities were as common before treatment as they were during, suggesting that such testing may also be of low value, according to Dr. Barbieri.

Overall, laboratory monitoring was common for lipid, liver function, and complete blood count testing, with many patients being tested monthly (Table). In addition, despite calls to reduce this monitoring, there were no substantial decreases in testing during the study period.

“Approximately 50% of patients had a complete blood count checked at baseline, and approximately 30% to 40% had it rechecked each month,” says Dr. Barbieri. With evidence from this and other studies demonstrating that complete blood count testing is of no value during isotretinoin therapy, “this testing represents probable overuse that could be avoided to reduce costs and improve the patient experience,” he adds. “In addition, although there have been suggestions to limit laboratory testing to baseline and at peak dose (or around 2 months into the course of therapy), laboratory testing appears to be prevalent throughout the course of therapy.”

Opportunities for Improvement

Dr. Barbieri explains that opportunities exist to improve the quality and cost of care in patients being treated with isotretinoin by reducing the frequency of lipid and liver function monitoring and by eliminating the practice of complete blood count monitoring.
“We conservatively estimate that reducing monitoring to align with recent recommendations could decrease spending by over $17 million annually,” he says. “While care should be individualized to each patient, for many patients, checking a lipid panel at peak dose to monitor for hypertriglyceridemia, with no further testing if abnormalities are not detected, may be a reasonable approach.”

References

The clinical utility of laboratory monitoring during isotretinoin therapy for acne and changes to monitoring practices over time
https://www.jaad.org/article/S0190-9622(19)30989-2/fulltext