The results of a long-term study into Japanese men with the hair loss
condition Male Pattern Baldness have been published in the Japanese Journal of Dermatology.
The study, which was funded by pharmaceutical giant GlaxoSmithKline (GSK), was centred on a drug named dutasteride
, which is broadly similar to the existing, clinically-proven hair loss drug finasteride in that it helps to stop the production of DHT
, the testosterone by-product that leads to follicle shrinkage and hair loss in men who are genetically predisposed to be sensitive to it.
Efficacy and side effects
Key goals of the Japanese study were to assess the efficacy of the drug, and also to understand what kind of side effects participants in the trial reported.
The results appear to be quite promising. Just over 100 men aged between 18 and 65 were given dutasteride 0.5mg daily for 52 weeks, and the study report states that hair growth, hair restoration and the overall appearance of the hair improved throughout the study.
The researchers also appear optimistic about the side-effects, stating that nasopharyngitis (an inflammation of the mucus membranes), erectile dysfunction and decreased libido were the most frequently reported adverse events, but that “most adverse events were mild.”
In summing up, the Japanese research team says that “as a potential future treatment option for male Androgenetic Alopecia (Male Pattern Baldness
), dutasteride 0.5mg exhibited long-term safety, tolerability and efficacy within this study population.”
As the trial was of a small scale, however, we understand that more wider reaching research, involving more participants in various locations and taking place over a longer period of time, is still likely to be necessary in order to build a fuller picture.
Dutasteride is an oral inhibitor of both type 1 and type 2 5αR. It was first approved worldwide for the treatment of benign prostatic hyperplasia (BPH) and was approved in Korea in 2009 for the treatment of Androgenetic Alopecia in men.
Earlier this year, production of a dutasteride product being manufactured under the brand name Zagallo
was interrupted “indefinitely” after irregularities were found at the French plant where it was being made.
Production of Zagallo ground to a halt after “out-of-place softgel capsules in several product batches were detected during quality control procedures.” These were removed prior to distribution to patients. It is not known if production has since resumed, nor is it known if Zagallo was the drug used in the Japanese trial, though it is certainly possible as Zagallo is a GSK drug.
According to the clinicaltrials.gov website, GlaxoSmithKline has also sponsored a bioequivalence study
of dutasteride within the past few years.
While dutasteride products have not been licenced for use on Male Pattern Baldness in the UK possibly due to concerns over the “half-life” of the drug (it stays in the body much longer than some other hair loss drugs) it is possible that GSK may pursue wider clearance for it if it proves to be a success in Japan.
Belgravia superintendent pharmacist, Christina Chihaker
(pictured), advises: "At present finasteride 1mg is the only drug approved by the FDA and MHRA for the treatment of androgenetic alopecia. Both finasteride and dutasteride are classed as Testosterone-5 alpha reductase inhibitors. Although both of these drugs have a similar mechanism of action and side effects there are differences. One of the most significant differences is the half-life of these drugs.
Finasteride has a half-life of approximately six hours in men aged 18-60 and increases to approximately eight hours in men aged more than 70. The half- life of dutasteride also increases with age. It is approximately 170 hours in men aged 20-49 years, approximately 260 hours in men aged 50 -69 years and approximately 300 hours in men aged over 70.
In plain terms this means that dutasteride takes weeks or even months to be eliminated from the system after discontinuation of treatment, whereas finasteride will be almost totally eliminated in about 3 days. For both of these drugs any of the known potential side effects appear to diminish with time. However, as the elimination half-life of dutasteride is much longer than that of finasteride, it will take longer for any side effects to diminish or dissipate following discontinuation of the drug. I think that although Avodart is a similar class of drug to finasteride 1mg, it would not be a good addition to the hair loss market
Alternatives to dutasteride
Recent predictions for the short term future of the worldwide hair loss drug market suggest that dutasteride may potentially be made available in Europe and the USA between 2017 and 2020. So what do men who want to halt their hair loss now, do?
In the UK there are two medically-proven products that are licensed by the MHRA for the treatment of Male Pattern Baldness.
The first is finasteride 1mg
- another oral inhibitor - which is taken in tablet form once per day. This drug inhibits the formation of the DHT which causes genetic hair thinning, stabilising hair loss and helping to prevent further deterioration of the affected follicles around the top of the scalp and hairline.
is the second licensed medicine for genetic hair loss and can be effective for stubborn areas such as a receding hairline
or thinning crown
. This is applied directly to the thinning areas in order to promote localised hair growth.
Any men concerned about losing their hair and wanting to explore hair restoration options open to them would be wise to consult a specialist who can provide a diagnosis and tailored treatment recommendations based on their findings, as their first step.