A. Moreau et al., PHOTOTOXIC AND PHOTOPROTECTIVE EFFECTS OF TOPICAL ISOTHIPENDYL, Photodermatology, photoimmunology & photomedicine, 11(2), 1995, pp. 50-54
Isothipendyl, an H1-receptor antagonist, is an antihistamince used as
an antiallergic drug. Its molecular structure is close to the phenothi
azines, but it has different photobiological properties. Like phenothi
azines, isothipendyl is phototoxic with ultraviolet A (UVA) but it red
uces the erythema response to UVB radiation. Isothipendyl seems to hav
e the same protective properties as a sunscreen because its UVB protec
tive properties are effective only if the substance is applied prior t
o exposure.