Clinical evaluation of Double Strength Isotrexin™ versus Benzamycin ® in the topical treatment of mild to moderate acne vulgaris

BACKGROUND: Topical retinoid therapy has been shown to be an effective means of treating both the inflammatory and non-inflammatory lesions of acne vulgaris. AIM: To assess the efficacy and safety of the test product, a gel containing isotretinoin 0.1% w/w and erythromycin 4.0% w/w, with a currently used and effective treatment for mild to moderate acne vulgaris, a gel containing benzoyl peroxide 5.0% w/w and erythromycin 3.0% w/w. METHODS: This multi-centre, single-blind (investigator blind), parallel group study compared the efficacy and safety of isotretinoin/erythromycin gel (Double Strength Isotrexin) once daily against benzoyl peroxide/erythromycin gel (Benzamycin twice daily in the topical treatment of mild to moderate acne vulgaris. Patients (n = 188) with a history (mean duration 3.3 years) of facial acne vulgaris and with 15-100 inflammatory lesions and/or 15-100 non-inflammatory lesions, but not more than three nodulocystic lesions, were included. At baseline and weeks 2, 4, 8 and 12, the investigator assessed efficacy (total number and severity of inflammatory and non-inflammatory lesions and acne grade) while subjective global change assessments of facial acne from baseline and symptom-specific skin tolerance were assessed by the patient. The investigator recorded an overall global assessment of skin tolerability at week 12. Adverse events were recorded throughout. RESULTS: The treatments were comparable with regard to their effects on inflammatory and non-inflammatory lesions and acne grade. Few adverse events were considered to be treatment-related. Both the isotretinoin/erythromycin and benzoyl peroxide/erythromycin gels were generally well tolerated. Compliance was better with the isotretinoin/erythromycin gel, which had the advantages of not requiring mixing or storage in a refrigerator, and was applied once rather than twice daily. CONCLUSIONS: Isotretinoin/erythromycin gel given only once daily showed comparable efficacy with benzoyl peroxide/erythromycin given twice daily in the treatment of mild to moderate acne vulgaris of the face.