Emoxypine (ethylmethylhydroxypyridine) succinate (MEXIDOL®) is a 3-hydroxypyridine derivative which is quite similar in structure to Vitamin B6 (pyridoxine). The most important components of the mechanism of action of Mexidol® are its antioxidant and membranotropic effects, the ability to modulate functioning of receptors and membrane-bound enzymes, restore a neurotransmitter balance. Due to its mechanism of action Mexidol® has a wide range of pharmacological effects, realized on at least two levels – neuronal and vascular. It has antihypoxic, anti-ischemic, neuroprotective, nootropic, vegetotrophic, anti-stress, anxiolytic, anticonvulsant, anti-alcohol, cardioprotective, anti-atherogenic, geroprotective and other actions. Under the action of Mexidol®, it is observed an improvement in cerebral circulation and microcirculation. Emoxypine is distributed in Russia but it is widely unknown in other regions.

Methyl aminolevulinate is a prodrug that is metabolised to Protoporphyrin IX (a photosensitizer) used in photodynamic therapy. Photosensitization following application of methyl aminolevulinate cream occurs through the metabolic conversion of methyl aminolevulinate (prodrug) to photoactive porphyrins (PAP), which accumulates in the skin lesions to which the cream has been applied. When exposed to light of appropriate wavelength and energy, the accumulated photoactive porphyrins produce a photodynamic reaction, resulting in a cytotoxic process dependent upon the simultaneous presence of oxygen. The absorption of light results in an excited state of porphyrin molecules, and subsequent spin transfer from photoactive porphyrins to molecular oxygen generates singlet oxygen, which can further react to form superoxide and hydroxyl radicals. Methyl aminolevulinate is used for topical use, in combination with 570 to 670 nm wavelength red light illumination, in the treatment of non-hyperkeratotic actinic keratoses of the face and scalp in immunocompetent patients when used in conjunction with lesion preparation (debridement using a sharp dermal curette).