BACKGROUND: Antihistamine drugs are used widely in many conditions. Although some antihistamines may cause a photosensitive reaction,many physicians are not awae of it. OBJECTIVE: For examination of the phototoxic potential of antihistamines, we performed the Candida albiecrns test which is simple, cheap, and good for the screening of many drugs. MEHTODS: Thirty microliters of each solute of various antihistamines were applied to the Sabraud dextrose agar plate in which Candida albicans were applied diffusly. Four hours after the application, 60J/cm fo UVA was irradiated for two days. The irradiated. plates and nonirradiated control ones were incubated in a dark room for 48 hours, and examined for lear zones arround the drug, which means a positive results for the phototoxic potential of the drugs. RESULTS: Mequitazine, thiethylperazine, perphenazine and cllorromazine showed positive results, whereas others did not. An additional Candida albicans test using 0.1%, 0.01%, and 0.001% of the positive drugs revealed tht chlorpromazine, thiethylperazine aderphenazine showed positive results at 0.1%, but negative at 0.01 and 0.001%. Mequitazine was niegative at 0.1, 0.01, and 0,001%, Additional studies of the Candida albicans test using 5% and 10% of the diphenhydramine and dimenhydrinate, those were known photosensitizers but they slowed negative results at this study and revealed very weak posit,ive result in 10% diphenhydramine. CONCLUSION: A photosensitive reaction such as photoallergy and persistent light react,ion may be triggered by the phenothiazine antihistamines. Negative result in 1%, and very weak positive results in 10% diphenhydramine may be due to different mechanism of phototoxicity, or the low phototoxic potential of diphenhydrainine.
Agar ; Candida albicans* ; Candida* ; Chlorpromazine ; Dermatitis, Photoallergic ; Dermatitis, Phototoxic* ; Dimenhydrinate ; Diphenhydramine ; Glucose ; Histamine Antagonists ; Mass Screening* ; Perphenazine ; Photosensitizing Agents ; Thiethylperazine