Dose Reduction May Lower Hair Loss Frequency, Allow for Longer Use of Isotretinoin for Acne

While hair loss is a documented side effect of isotretinoin for patients taking the treatment for acne, there are limited data pointing to the frequency of hair loss based on dosage. However, in a new study, researchers found that the frequency of hair loss ranges between 3%-6% based on the dose.

On the higher end, frequency of hair loss is comparable to the frequency of other side effects, such as dry eyes, that are commonly discussed with patients. Based on their findings, the researchers suggested providers discuss the side effect with patients prior to initiating isotretinoin and monitor the side effect during treatment.

“Hair loss in the form of telogen effluvium is a reported side effect of isotretinoin that can lead to treatment discontinuation. Although its mechanisms are unclear, retinoids are thought to arrest the onset of the anagen phase of the hair cycle and impair the anchoring of hair during the telogen phase, ultimately increasing hair shedding,” described the researchers, who added that “the exact frequency and associated dose dependency of hair loss with the use of isotretinoin remain unclear.”

Data from 22 studies were collected on reported hair loss with isotretinoin treatment, showing a hair loss frequency of 3.2% for patients receiving <0.5 mg/kg/day and a frequency of 5.7% for patients receiving ≥0.5 mg/kg/day.

With current treatment recommendations suggesting that patients be clear of acne for 1-2 months before discontinuing isotretinoin to reduce the risk of recurrence, the researchers recommended prescribing a lower dose for a longer period to achieve the benchmark before discontinuing. While stressing the importance of dose reduction for hair loss frequency, the researchers also included intermittent dosing as a possible alternative for treatment, particularly in patients with mild-to-moderate acne.

Just 1 small study offered data on time to hair loss onset, which indicated a median time to onset of 4 weeks. The researchers noted that it’s not clear whether the duration or dose of isotretinoin impacts the time to onset of hair loss.

There were 2 studies that explored the reversibility of hair loss with isotretinoin treatment, one of which detailed hair loss in 150 patients who experienced persistent hair loss after stopping treatment. However, the researchers emphasized that there are no data to support the finding and both the time frame and number of affected patients were not clear. The second study was retrospective and suggested that hair loss was reversible in 30 patients receiving a high dose of treatment.

“The reversibility and extent of hair regrowth are important to consider because patients may view permanent hair thinning as a barrier to therapy,” wrote the researchers. “Although the product monographs of isotretinoin formulations (Clarus, Epuris, and Accutane) warn that hair loss may persist after treatment is completed, there is no definitive evidence to support this prognosis.”

Reference:

Lytvyn Y, McDonald K, Mufti A, Beecker J. Comparing the frequency of isotretinoin-induced hair loss at <0.5-mg/kg/d versus ≥0.5-mg/kg/d dosing in acne patients: a systematic review. J Am Acad Dermatol. Published online February 10, 2022. doi:10.1016/j.jdin.2022.01.002