title: Duration of skin photosensitivity and incidence of photosensitivity reactions after administration of verteporfin.
abstract: BACKGROUND
  Verteporfin (Visudyne, Novartis AG) is a light-activated drug that reduces the risk of vision loss in patients with certain types of choroidal neovascularization (CNV). Because photosensitivity can occur with photosensitizers, it is important for ophthalmologists providing verteporfin therapy to understand its time course and duration, as well as the incidence of photosensitivity reactions.
  
  
  METHODS
  Data were obtained from three sources: 1) the time course of skin photosensitivity in 17 volunteers by measuring erythema/edema over time after verteporfin, using red light exposure; 2) the duration of skin photosensitivity in 30 patients with skin cancer by exposing skin to simulated solar light and calculating the daily minimal erythematous dose; and 3) the incidences of photosensitivity reactions as recorded in three phase III trials in patients with CNV secondary to age-related macular degeneration or pathologic myopia who received the regimen of verteporfin therapy currently approved by regulatory authorities (infusion of 6 mg/m(2) body surface area).
  
  
  RESULTS
  1) Skin photosensitivity was high at the first timepoint of 1.5 hours after dosing and decreased rapidly thereafter; 2) the duration of skin photosensitivity was dose dependent, ranging from 2.0 to 6.7 days at 6 to 20 mg/m(2), respectively (mean of 2 days at a dose of 6 mg/m(2)); and 3) photosensitivity reactions occurred in only 2.2% of patients in the phase III trials, including two severe events, one secondary to extravasation. All treatment-related reactions in the phase III trials occurred within the first 2 days after dosing, with the exception of two mild reactions and one moderate reaction that occurred 3 days after treatment.
  
  
  CONCLUSIONS
  Verteporfin is associated with short-lived photosensitivity and a low incidence of photosensitivity reactions in clinical trials, most of which could probably have been avoided by adherence to protocol instructions for skin protection.
authors.affiliation: QLT Inc., 887 Great Northern Way, Vancouver, British Columbia V5T 4T5, Canada.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Houle
authors.forename: H Andrew
authors.initials: HA
authors.lastname: Strong
mesh_terms: D000328:Adult; D000368:Aged; D020256:Choroidal Neovascularization / Q000188:drug therapy / Q000209:etiology; D017454:Dermatitis, Photoallergic / Q000145:classification / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008268:Macular Degeneration / Q000150:complications; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000150:complications; D010778:Photochemotherapy / Q000009:adverse effects*; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000009:adverse effects*; D011166:Porphyrins / Q000008:administration & dosage / Q000009:adverse effects*; D012867:Skin / Q000187:drug effects*; D012878:Skin Neoplasms / Q000188:drug therapy / Q000473:pathology; D013997:Time Factors; D000077362:Verteporfin
chemical_list: D017319:Photosensitizing Agents; D011166:Porphyrins; D000077362:Verteporfin