Slowing hair loss progression

September 1, 2007

In a recent unique study involving 17 pairs of male identical twins, dutasteride proved to be highly effective in the treatment of androgenic alopecia, compared to placebo controls.

Key Points

Little Rock, Ark. - In a novel study of male identical twins with male pattern hair loss, the use of dutasteride significantly slowed the progression of hair loss and enhanced hair growth, compared with placebo.

Dow B. Stough, M.D., clinical professor of dermatology, University of Arkansas for Medical Sciences, Little Rock, Ark., and Burke Pharmaceutical Research, Hot Springs, Ariz., conducted a randomized, double-blind, placebo-controlled, single-center study consisting of 17 pairs of male identical twins suffering from androgenic alopecia. The study's purpose was to evaluate the efficacy of dutasteride, compared with placebo. Over 12 months, one twin from each identical pair received 0.5 mg a day of dutasteride, while the other twin received placebo. There were no concomitant therapies or surgical procedures in any of the study participants.

Halting, reversing progression

"We saw in our study that in those patients who received dutasteride therapy, a slowed progression of this hair loss was evident compared with those who received placebo. Furthermore, there was a significantly improved hair growth at one year compared with those patients who received placebo, based on the analysis of the investigator who used standardized clinical photographs and hair counts, as well as patient self-assessment questionnaires that the study participants received," Dr. Stough tells Dermatology Times.

Study results showed that at the 12-month follow-up, there were 3.8 fewer hairs in the placebo group compared with 16.5 more hairs in the dutasteride patient group. In 11 sets of twins, the mean hair count indicated 22.2 more hairs in the dutasteride-treated patients than in the patients who received placebo.

Dr. Stough says no serious clinical or laboratory adverse events occurred in the study. Two treatment-related clinical adverse experiences were possibly related to the study; these were described as decreased libido of mild to moderate severity.

"Dutasteride is a potent, selective orally active inhibitor of the enzyme five alpha-reductase type two in humans. The drug is able to lower serum and scalp dihydrotestosterone levels without having intrinsic androgenic, anti-androgenic, estrogenic, anti-estrogenic or progestational effects. Dutasteride has been shown to significantly increase hair count and hair weight, improve the ratio of anagen to telogen hairs, improve scalp coverage based on assessment of standardized global photography, and improve the satisfaction of patients with the appearance of their hair," Dr. Stough says.

He noticed that the majority of those patients who received placebo showed a visible worsening in scalp hair coverage, based on global photographic assessment of the vertex scalp at one-year follow-up.

Twins: Built-in controls

According to Dr. Stough, androgenic alopecia affects 50 percent of men by the age of 50.

He says the condition is thought to be genetically controlled and occurs in males with an inherited sensitivity to the effects of dihydrotestosterone on scalp hair follicles.

"Because androgenic alopecia is under genetic control and identical twins share the same genetic code, the comparison of paired data between twins is a highly efficient way of evaluating the efficacy of treatment in a limited number of patients, as each twin serves as a control," Dr. Stough says.

Interestingly, the phenotypic expression of the androgenic alopecia was similar - but not identical - in each pair, evidenced from careful examination of baseline global photographs for each pair of twins.