(CBS News) Researchers have found that a significant proportion of men who developed persistent sexual side effects from using finasteride - known by its brand name Propecia - also suffer from depressive symptoms and suicidal thoughts.
"The potential life-threatening side-effects associated with finasteride should prompt clinicians to have serious discussions with their patients," Dr. Michael S. Irwig, an assistant professor of medicine in the division of endocrinology at the George Washington University School of Medicine and Health Sciences, said in the press release.
Finasteride is used to treat male pattern hair loss - the thinning of the hair on the scalp leading to a receding hairline or balding on the top of the head - according to the National Institutes of Health. It can also be used to treat benign prostatic hypertrophy or enlargement of the prostate gland - under the brand name Proscar -which can cause problems such as frequent and difficult urination and the sudden inability to urinate. The type looked at in the study was finasteride as found in Propecia. Both Propecia and Proscar are manufactured by Merck.
Previous research has tied the drug to sexual side effects, and in April 2012, the U.S. Food and Drug Administration added warning labels to Merck's drugs. Propecia labels will now include warnings for libido disorders, ejaculation disorders and orgasm disorders that continued for men even months after stopping the drug, the FDA said at the time.
For the study, 61 men who formerly used finasteride and had sexual side effects for at least a three month-period were questioned about their demographic information, medical and psychiatric histories, and information on medication use, sexual function, and alcohol consumption. A control group of 29 men who had male pattern hair loss but had never used finasteride nor had any history of psychiatric problems were also interviewed.
According to the results, 11 percent of the male finasteride users had mild depressive symptoms; 28 percent had moderate symptoms; and 36 percent had severe symptoms. A significant, 44 percent of subjects had suicidal thoughts. Only 10 percent of the control group had mild depressive symptoms, and 3 percent had suicidal thoughts.
"The preliminary findings of this study warrant further research with controlled studies," the researchers concluded.
The study can be found in the August 2012 issue of the Journal of Clinical Psychiatry.