Interactions between calcipotriene and ultraviolet light.
BACKGROUND
Calcipotriene is often used with UVB or PUVA, but interactions between UV radiation and calcipotriene have not been examined extensively.


OBJECTIVE
Our purpose was to examine interactions between calcipotriene and UV light.


METHODS
Minimal erythema doses (MEDs) were determined with UVB and immediate pigment darkening was measured for UVA. The effect of calcipotriene ointment applied before phototesting was examined. Thick and thin applications of calcipotrience were compared. Calcipotriene ointment was applied to a small area on the skin before phototherapy. Patients received either UVB, PUVA, UVA, or no phototherapy. After phototherapy, the ointment was collected and assayed by reverse-phase, high-performance liquid chromatography.


RESULTS
MEDs for UVB and immediate pigment darkening for UVA were unaffected by calcipotriene. Thick application of calcipotriene, however, increased the MED, UVA caused substantial reductions in the concentration of detectable calcipotriene.


CONCLUSIONS
When used in conjunction with PUVA, calcipotriene should be applied after exposure to UVA.
Lebwohl
M
M
Department of Dermatology, Mount Sinai School of Medicine, New York 10029-6574, USA.
Hecker
D
D
Martinez
J
J
Sapadin
A
A
Patel
B
B
D002117:Calcitriol / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D003879:Dermatologic Agents / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D011701:PUVA Therapy; D011565:Psoriasis / Q000188:drug therapy / Q000532:radiotherapy; D014467:Ultraviolet Therapy
D003879:Dermatologic Agents; C055085:calcipotriene; D002117:Calcitriol