Adverse Events with Finasteride or Dutasteride: FAERS

A study analyzed adverse events reported to the US Food and Drug Administration Adverse Event Reporting System (FAERS) regarding 5-alpha reductase inhibitors (5ARIs) between April 2011 and October 2014. The study found that lower doses of finasteride were associated with a higher frequency of adverse events reported than higher doses. There were significant differences in the adverse event frequency reported for 1mg and 5mg finasteride doses for some post-finasteride syndrome (PFS) domains, comprising the sexual and psychological domains. The only adverse event reported with dutasteride was back pain. The authors conclude that PFS requires further research with placebo-controlled, randomized trials with validated questionnaires and prior sexual and mental health histories followed for a sufficient length of time.