Several systemically administered drugs with antimicrobial effect have undesirable phototoxic effects. This group includes some antibiotics (e.g., tetracycline, fluorochinolons, and also macrolids), sulphonamides and related chemotherapeutics, antimycotics, tuberculostatics, antiviral drugs and antimetabolites. Doctors should know the phototoxic effect of those drugs in advance, because of the possible time shortage they might have when they prescribe the drugs. The first condition is to obtain the relevant personal history data, and in case the phototoxic reaction develops, to terminate the unsuitable drug, to change it for another, to administer antihistaminics, sometimes corticoids, prevent exposition to sun, and administer local anti-inflammatory dermatological drugs.

        Key words: phototoxicity, photosensitization, UV light, UVA, UVB, antimicrobial drugs.