Can men use dutasteride and finasteride together?

Finasteride is formally FDA approved for the treatment of male balding. While not formally FDA approved, dutasteride can be used off label in the treatment of male balding or 'androgenetic alopecia'. Both drugs can be used alone or with other therapies such as hair transplantation, minoxidil and platelet rich plasma. 

Finasateride is an inhibitor of the enzyme 5 alpha reductase type 2  and dutaseride is an inhibitor of both 5 alpha reductease type 1 and type 2. Dutasteride is more potent and leads to greater reductions of dihydrotestosterone (DHT). Side effects are also greater.

Patients who have a partial response to finasteride often wonder if they should switch to dutaseteride or add dutasteride. Adding a very small dose of once weekly dutasteride can often be a good option. An Australian study in 2013 reported a 47-year-old man who was initially treated with finasteride for male pattern balding. Despite continuous treatment, after year 4 his hair density was not as good as previous years, and low-dose dutasteride at 0.5 mg once per week was added to the finasteride therapy. Interestingly, this resulted in a dramatic increase in his hair density, demonstrating that combined therapy with finasteride and dutasteride can improve hair density in patients already taking finasteride.

Comment

This study shows how careful planning of safe medical treatments can lead to improvements in patient's outcomes.

Reference

Boyapati A and Sinclair R. Combination therapy with finasteride and low-dose dutasteride in the treatment of androgenetic alopecia. Australas J Dermatol. 2013 Feb;54(1):49-51.