Some subfertile men may experience hormonal changes that result in lower sperm counts.


WASHINGTON, D.C.—A handful of cases suggest that finasteride (Propecia), a treatment for male pattern hair loss, may be harming male fertility.

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Finasteride, a 5-alpha-reductase inhibitor used to treat BPH, is also available as a 1-mg tablet taken daily by men wishing to prevent hair loss. It now appears that this dosage can decrease total sperm counts in some men with suboptimal fertility. The treatment does not significantly affect overall semen parameters in young, healthy men.


“Propecia is widely used in young men who are preventing hair loss, and the reproductive consequences have never been discussed,” said Kirk Lo, MD, assistant professor in the department of surgery at the University of Toronto in Canada. “It may not be an issue in normal, healthy men, but in the subfertile population perhaps there is a change in the hormonal balance. Propecia may change testosterone and other hormone levels.”


Stopping drug improves sperm

At the American Society for Reproductive Medicine annual meeting here, Dr. Lo and his colleagues reported that they observed sperm concentrations improve significantly in two men six months after they stopped taking finasteride. In one of the men—a 34-year-old with azoospermia—the improvements were strong enough to correct the condition and eliminate the need for testicular biopsy. The patient, who had a preliminary diagnosis of obstructive azoospermia and was scheduled for testicular biopsy, had been taking finasteride 1 mg per day for hair loss for four years.


Several semen analyses over a 12-month period had revealed azoospermia with sperm rarely seen. The man’s follicle-stimulating hormone (FSH) level was 3 IU/L, his luteinizing hormone (LH) level was 3.3 IU/L, and his total testosterone level was 23 nmol/L. An examination confirmed normal testicular volume and the presence of bilateral vas deferens.


The man was advised to stop taking finasteride, and 12 weeks after doing so, his sperm concentration was 0.9 2 106/mL. It climbed to 5.5 2 106/mL after six months without the drug. The patient was then told to proceed with other fertility treatments.


In the second case, a 32-year-old male with severe oligospermia had a semen volume of 1.4 mL, sperm concentration of 4 2 106/mL, 14% mo-tility, 5% normal forms, and normal testicular size. He had been taking finasteride 1 mg/day for three years. Three months after he stopped taking the drug, his sperm concentration improved to 6.6 2 106/mL, which rose to 18.7 2 106/mL after

six months. 


Dr. Lo said these cases suggest that discontinuing the use of finasteride 1 mg in the infertility population may help improve semen parameters and allow for less invasive fertility treatments. “We now have five cases in total, and at this meeting we are talking to our colleagues who are reporting two or three cases,” Dr. Lo told Renal & Urology News. “So now we are trying to get everyone together so we can report on a bigger series. It may be an issue all over the world because Propecia use is getting more popular, so physicians need to know about this.”

Paul Turek, MD, professor of urology at the University of California, San Francisco, called this is a very important issue. “The FDA does not require fertility studies of these drugs, and it has been the suspicion of most of us in the field that if you take this drug for more than five years then you might consider stopping it because it does look like a player in decreasing spermatogenesis,” he explained. “But this needs to be confirmed, and it may be a good multicenter-institution study to consider undertaking.”


Dr. Turek said he has seen six similar cases and he has encouraged his patients to stop using finasteride for treating hair loss.