Efficacy of 5% minoxidil versus combined 5% minoxidil and 0.01% tretinoin for male pattern hair loss: a randomized, double-blind, comparative clinical trial.
BACKGROUND
5% topical minoxidil solution has been widely used to stimulate new hair growth and help stop hair loss in men with androgenetic alopecia (AGA). However, it is not convenient for patients to continue applying the solution twice daily on a regular basis. Tretinoin is known to increase the percutaneous absorption of minoxidil and, therefore, to enhance the response of AGA to minoxidil. For this reason, it was assumed that tretinoin would be helpful in alleviating the inconvenience associated with the recommended twice-daily application of minoxidil.


OBJECTIVE
To compare the efficacy and safety of therapy using a combined solution of 5% minoxidil and 0.01% tretinoin once daily with those of the conventional 5% topical minoxidil therapy applied twice daily in the treatment of AGA.


METHODS
A total of 31 male patients (aged 28-45 years, mean 39.7+/-4.5) with AGA (Hamilton-Norwood classification type III-V) were randomly assigned into two groups, one in which 5% minoxidil was applied to the scalp twice daily and the other in which the combined agent was applied once daily at night together with a vehicle placebo in the morning. The efficacy parameters were: (i) changes in total hair count, non-vellus hair count, anagen hair ratio, linear hair growth rate, and mean hair diameter assessed by macrophotographic image analysis; and (ii) the patient's and investigator's subjective assessments.


RESULTS
After therapy, increases in the macrophotographic variables of total hair count and non-vellus hair count were shown in both treatment groups. There were no statistically significant differences between the two treatment groups with respect to changes in macrophotographic variables or scores on subjective global assessments by patients and the investigator. The incidence of adverse effects such as pruritus or local irritation was similar in the 5% minoxidil group (4 of 14 subjects) and the combined agent group (5 of 15 subjects).


CONCLUSIONS
The efficacy and safety of combined 5% minoxidil and 0.01% tretinoin once-daily therapy appear to be equivalent to those of conventional 5% minoxidil twice-daily therapy for the treatment of AGA.
Shin
Hyo Seung
HS
Department of Dermatology, Seoul National University College of Medicine, and Seoul National University Boramae Hospital, Seoul, Korea.
Won
Chong Hyun
CH
Lee
Seung Ho
SH
Kwon
Oh Sang
OS
Kim
Kyu Han
KH
Eun
Hee Chul
HC
D000287:Administration, Topical; D000328:Adult; D000505:Alopecia / Q000188:drug therapy* / Q000473:pathology; D003879:Dermatologic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D006197:Hair / Q000187:drug effects* / Q000254:growth & development; D006801:Humans; D008297:Male; D008875:Middle Aged; D008914:Minoxidil / Q000008:administration & dosage* / Q000009:adverse effects; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D016896:Treatment Outcome; D014212:Tretinoin / Q000008:administration & dosage* / Q000009:adverse effects
D003879:Dermatologic Agents; D014212:Tretinoin; D008914:Minoxidil