Sulfas medicines are used in various pathologies. However, previous studies reported photochemical instability, which in some cases can be linked to a photosensitizer in the generation of active oxygen species, especially singlet oxygen. This paper presents advances in reference to the characteristics of reactivity compared to electrophilic species such as singlet oxygen with acetazolamide, as assessed through theoretical studies, with the determination of Fukui indexes (DFT), through the calculation of Mulliken charges. In