Abstract
Cyamemazine (CMZ), chlorpromazine (CPZ) and carprofen methyl ester (CPM) are drug derivatives that contain a tricyclic heteroaromatic system (Chart 1). This moiety acts as a chromophore, allowing light absorption in the UVB-UVA region; hence, CMZ, CPZ and CPM are potential photosensitizing agents. After excitation, the singlet and triplet excited states of these drugs are formed, together with other reactive species, such as carbon-centered free radicals. These intermediates are claimed to be real mediators of biological damage. The three examples presented here illustrate how photosensitization by drugs can produce chemical modifications of biomolecules, which can ultimately lead to photobiological effects.
