Photodynamic treatment photosensitized reactions

Photodynamic therapy with verteporfin through 24 months of follow-up and treatment in both the TAP and VIP studies appeared quite safe. The treatment was well tolerated with minimal adverse events attributable to treatment. Photosensitivity reactions were rare and lower in incidence in the VIP study (1%) than the TAP study (3%) despite the shorter recommended protection period of 24 hours compared with 48 hours. Allergic reactions were also rare and more frequent in the placebo groups. The only other nonocular adverse event related to treatment was lower back pain during verteporfin infusion, which occurred in a total of 15 people across both studies. 

Aminolevulinic acid (ALA HCl, Levulan Kerastick) is indicated for the treatment of nonhyperkeratotic actinic keratosis of the face and scalp. It has two components, an alcohol solution vehicle and ALA HCl as a dry solid. The two are mixed prior to application to the skin. When applied to human skin, ALA is metabolized to protoporphyrin, which accumulates and on exposure to visible light produces a photodynamic reaction that generates reactive oxygen species (ROS).The ROS produce cytotoxic effects that may explain therapeutic efficacy. Local burning and stinging of treated areas of skin due to photosensitization can occur. 

Two-Color Two-Laser DNA Damaging Photodynamic therapy (PDT) is a promising treatment for cancer based on the photosensitized oxidative reaction at the diseased tissues producing cell death, and DNA is considered as a potential target [122]. Compared with surgery and chemotherapy, the... 

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