Weekly Isotretinoin Therapy for the Treatment of Moderate Acne Vulgaris

In current Dermatology practice, options for moderate acne vulgaris remain limited. Moderate acne is clinically defined as acne that has not responded to at least three months of topical therapy and is not severe enough for initial treatment with a conventional course of isotretinoin (formerly known as Accutane). The mainstay of treatment for moderate acne remains long courses of oral antibiotics, mainly tetracyclines (doxycycline, minocycline) and occasionally trimethoprim-sulfamethoxazole. Males with moderate acne, in particular, are especially limited in their treatment options as they are not eligible for hormonal management (spironolactone, oral contraceptive pills) like their female counterparts. Additionally, even for those regardless of gender who may eventually qualify for a traditional isotretinoin course, many insurance companies first require failure to respond to at least three months of oral antibiotics. Nagler et. al found that the average antibiotic use for moderate to severe acne prior to receiving isotretinoin was 331 days, with 15.3% of patients prescribed antibiotics for three months or less, 88% for six months or more, and 46% for at least one year.1 Despite the widespread use of oral antibiotics in acne, antibiotic resistance is considered a global threat per the CDC2, and there have been calls to limit their use in acne because of concerns of bacterial resistance3,4,5. Because of this, there is a significant need for more research on alternative treatment options for moderate acne.

Once weekly isotretinoin dosing has the potential to significantly improve moderate acne with good patient satisfaction and safety profile; however, no study findings on this treatment option have been published to date. The efficacy of isotretinoin, an oral vitamin A derivative, for treatment of acne has been well established. The traditional treatment course for severe acne consists of once to twice daily dosing (0.5-1 mg/kg/day) for 4-7 months (or 150mg/kg total cumulative dose). Though efficacious, there are numerous reported side-effects due to achieving the cumulative dose rapidly by once to twice daily dosing, such as severe dry skin, lips, and eyes, as well as liver enzyme and lipid abnormalities. Because of this, there have been studies exploring alternative isotretinoin dosing regimens including microdose, lower daily dose regimens (0.15-0.4 mg/kg/day6, 0.25-0.4 mg/kg/day7, 0.3-0.4 mg/kg/day8,9, in addition to 5 mg/day10 and 0.15-0.28 mg/kg/day with additional of local application of 1% clindamycin gel every other day11) and daily dosing for 7-10 consecutive days (0.5-0.7 mg/kg/day) out of each month only.7,12,13,14 All studies had favorable outcomes with alternative dosing, despite the lower total cumulative dose versus conventional dosing. Those who also analyzed adverse effect rates with alternative isotretinoin dosing found that these were either rarely observed or similar to conventional dosing.6,8,9,10,12,14 In contrast, the potential adverse effects of oral antibiotics used for acne include photosensitivity and nausea/vomiting (doxycycline), drug-induced pigment deposition and drug-induced systemic lupus erythematosus (minocycline), and angioedema and drug rashes including drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome (trimethoprim-sulfamethoxazole). Interestingly, rates of acne recurrence between alternative isotretinoin dosing and conventional dosing were similar at follow-up,6,7,9 despite a much older study from 1984 that found otherwise.15 Additionally, cost of alternative isotretinoin dosing was lower than with conventional dosing,8,9,13 and patient satisfaction was highest in the alternative dosing groups.7,10 For these reasons, this study aims to evaluate the efficacy of once weekly isotretinoin dosing (1-1.5 mg/kg/week) as a potential alternative to oral antibiotics for the treatment of patients with moderate acne. Secondary endpoints include patient satisfaction and adverse effects.