title: Finasteride-induced secondary infertility associated with sperm DNA damage.
abstract: OBJECTIVE
  To report a case of low-dose finasteride-induced secondary infertility with associated elevated sperm DNA fragmentation index (DFI) and otherwise normal semen parameters.
  
  
  METHODS
  Case report.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  A 48-year-old man on low-dose finasteride and his 37-year-old wife with normal menses and normal gynecologic exam.
  
  
  METHODS
  Determination of sperm DFI and discontinuation of low-dose finasteride.
  
  
  METHODS
  Sperm DFI.
  
  
  RESULTS
  The sperm DFI done a year earlier was 30%. This value was unchanged when repeated 2 months later. The patient was advised to stop finasteride. Three months after discontinuing the finasteride, the DFI decreased to 21% and subsequent DFI after another 3 months improved to 16.5%. To date, there is still no documented full-term pregnancy or live birth.
  
  
  CONCLUSIONS
  The significant reduction in DFI within 3 months of finasteride cessation and continued improvement suggests a causal link between finasteride and sperm DNA damage. We hypothesize that low-dose finasteride may exert a negative influence on sperm DNA integrity, resulting in increased pregnancy losses. We suggest that in infertile men using finasteride, sperm DFI should be measured in addition to semen parameters, and a trial of discontinuation of finasteride may be warranted.
authors.affiliation: Division of Urology, Department of Surgery, McGill University, Montreal, Quebec, Canada.
authors.forename: Hin Yu Vincent
authors.initials: HY
authors.lastname: Tu
authors.forename: Armand
authors.initials: A
authors.lastname: Zini
mesh_terms: D058891:5-alpha Reductase Inhibitors / Q000008:administration & dosage / Q000009:adverse effects; D000328:Adult; D000505:Alopecia / Q000188:drug therapy; D004249:DNA Damage / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005260:Female; D018120:Finasteride / Q000008:administration & dosage / Q000009:adverse effects*; D006801:Humans; D007248:Infertility, Male / Q000139:chemically induced* / Q000235:genetics / Q000473:pathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D013094:Spermatozoa / Q000187:drug effects* / Q000378:metabolism; D028761:Withholding Treatment
chemical_list: D058891:5-alpha Reductase Inhibitors; D018120:Finasteride