Safety and Tolerability of the Dual 5-Alpha Reductase Inhibitor Dutasteride in the Treatment of Androgenetic Alopecia.

Background: After the approval of dutastride for androgenic alopecia (AGA) in 2009, Korean authority required a post-marketing surveillance to obtain further data on its safety profile.

Objective: The objective was to monitor adverse events (AEs) of dutasteride 0.5 mg in Korean AGA male patients in a clinical practice environment.

Methods: Open label, multi-center, non-interventional observational study was done from July 2009 to July 2013. AGA subjects (18~41 years of age) with no experience of dutasteride were enrolled. Dosage regimen was recommended according to the prescribing information. The incidences of any AEs, serious adverse events (SAEs), and adverse drug reactions (ADRs) were evaluated. Multiple logistic regression method was used to identify risk factors related to ADRs. Effectiveness was generally evaluated by physicians.

Results: During study period, 712 subjects were enrolled. The subjects of 29.3±6.0 years old exposed to dutasteride for 204.7±161.5 days. One hundred and ten (15.4%) of subjects reported 138 AEs. Four subjects (0.6%) reported 5 SAEs (right radius fracture, 2 events of chronic follicular tonsillitis, influenza infection, and acute appendicitis). Sixty-six subjects (9.3%) reported 80 ADRs. Most frequent ADRs were libido decreased (9 subjects, 1.3%), dyspepsia (8 subjects, 1.1%), impotence (7 subjects, 1.0%), and fatigue (5 subjects, 0.7%). Other interested ADRs were sexual function abnormality (4 subjects, 0.6%), gynecomastia (2 subjects, 0.3%), and ejaculation disorder (1 subject, 0.1%). Most subjects (78.6%) showed overall improvement after treatment of dutasteride in the effectiveness.

Conclusion: Dutasteride 0.5 mg is to be well-tolerated in 18 to 41 years old AGA patients in a clinical practice environment.