Increase in prescribing of systemic tetracyclines and isotretinoin for treatment of acne vulgaris in Norwegian adolescents from 2005 to 2014 Ingvild Odsbu1, Randi Selmer2, Cecilia Stålsby Lundborg1 and Hege Salvesen Blix2 1Department of Public Health Sciences, Karolinska Institutet, Stockholm 2Department of Pharmacoepidemiology, Norwegian Institute of Public Health, Oslo

Aim To investigate the prescribing of systemic drug therapy for the treatment of severe acne vulgaris in adolescents over a 10 year period

Materials and methods The Norwegian prescription database Period 2005 – 2014 Individuals aged 14-24 years Tetracyclines (doxycycline, lymecycline, oxytetracycline and tetracycline) and isotretinoin

Treatment of severe acne vulgaris Disturbs the normal gut microbiota Contributes to antibiotic resistance Gives side effects Systemic tetracyclines Isotretinoin Teratogenic

Increase in one-year prevalence

Increase in incidence rate

Conclusions Increased prescribing rates observed in the period 2005-2014 Tetracyclines most commonly prescribed Isotretinoin increasingly prescribed Tetracyclines: greater increase in prevalence and incidence of use in women compared to men