L-phenylalanine and UVA irradiation in the treatment of vitiligo.
In order to evaluate the efficacy of L-phenylalanine (L-Phe) in combination with UVA therapy for vitiligo an open trial (149 patients, 18 months) and a small double-blind trial (32 patients, 6 months) were conducted. Oral L-Phe loading resulted in peak plasma levels of L-Phe after 30-60 min and a slight increase in the plasma tyrosine level. Response to L-Phe plus UVA irradiation was positive, and various grades of repigmentation not exceeding 77% in the open and 60% in the blind trial were observed. An increased L-Phe dose resulted in increased L-Phe plasma levels but not in improved clinical results. The optimal L-Phe dose appears to be lower than 50 mg/kg/day. Although it is difficult to draw firm conclusions from the present investigation, we think that L-Phe may have a place in the treatment of vitiligo and its role merits further investigation.
Siddiqui
A H
AH
Department of Dermatology, Academisch Medisch Centrum, University of Amsterdam, The Netherlands.
Stolk
L M
LM
Bhaggoe
R
R
Hu
R
R
Schutgens
R B
RB
Westerhof
W
W
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D003131:Combined Modality Therapy; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D006801:Humans; D008875:Middle Aged; D010649:Phenylalanine / Q000627:therapeutic use*; D014443:Tyrosine / Q000097:blood; D014467:Ultraviolet Therapy; D014820:Vitiligo / Q000097:blood / Q000628:therapy*
D014443:Tyrosine; D010649:Phenylalanine