A Drug Safety Update issued by the MHRA in May 2017 discussed reports received by MHRA linking finasteride 1mg (Propecia) with depression and in rare cases suicidal thoughts.
The 1mg dose is licensed for the treatment of male pattern hair loss, whilst the 5mg strength (Proscar) is licensed for the treatment of benign prostatic hyperplasia.
Finasteride is a 5α-reductase inhibitor. Therapeutic inhibition of the enzyme 5α-reductase prevents the conversion of testosterone to the more potent androgen dihydrotestosterone (DHT). DHT is a recognised trigger for pigmented capillary hairs to be gradually replaced by smaller and less pigmented hairs causing the patterns recognised as androgenetic alopecia (male pattern baldness).
MHRA have received reports of episodes of depression associated with the use of Propecia. Some patients have also reported having suicidal thoughts. These reports have involved men with and without a history of depression.
Depressed mood has been associated with Propecia previously. The recent review has shown that more significant depression can occur and consequently the associated advice has been updated.
MHRA has provided the following advice to healthcare professionals:
- Since finasteride has been marketed there have been a number of spontaneous adverse drug reaction reports suggesting a possible link to depression, and in rare cases, suicidal thoughts
- Advise patients to stop finasteride 1mg (Propecia) immediately if they develop depression and inform a healthcare professional
- Be aware that the product information for finasteride 5mg (Proscar) already lists depression as a possible adverse reaction
Healthcare professionals should also consider that adverse reactions related to sexual function have been reported associated with finasteride. These adverse reactions include decreased libido, erectile dysfunction and ejaculation disorders.
All suspected adverse reactions should be reported to the MHRA via the Yellow Card Scheme. https://yellowcard.mhra.gov.uk/
 Drug Safety Update volume 10 issue 10, May 2017. https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/615844/FINAL_DSU_May_pdf.pdf