Porfimer sodium, sold as Photofrin, is a photosensitizer used in photodynamic therapy and radiation therapy and for palliative treatment of obstructing endobronchial non-small cell lung carcinoma and obstructing esophageal cancer. Porfimer is a mixture of oligomers formed by ether and ester linkages of up to eight porphyrin units. In practice, a red light source emitting at 630 nm is used to excite the Porfimer oligomers.Porfimer is Haematoporphyrin Derivative (HpD) (See PDT). Approvals and indications
It was approved in Canada in 1993 for the treatment of bladder cancer. It was approved in Japan in 1994 (for early stage lung cancer?). It was approved by the U.S. FDA in December 1995 for esophageal cancer, and in 1998, it was approved for the treatment of early non-small cell lung cancer.In August 2003 the FDA approved its use for Barretts esophagus. References
External links
Photofrin 
Photofrin marketing info 
Side effects of PDT with Photofrin
History of Photofrin
squatting down, walking up or down stairs, looking out of the window of a moving car or train). Vertigo is called height vertigo when the sensation of vertigo is triggered by heights. Height vertigo is caused by a conflict between vision, vestibular and somatosensory senses. This occurs when vestibular and somatosensory systems sense a body movement that is not detected by the eyes. More research indicate that this conflict leads to both motion sickness and anxiety. Causes
Traditionally, acrophobia has been attributed, like other phobias, to conditioning or a traumatic experience. Recent studies have cast doubt on this explanation. Individuals with acrophobia are found to be lacking in traumatic experiences. Nevertheless, this may be due to the failure to recall the experiences, as memory fades as time passes. To address the problems of self report and memory, a large cohort study with 1000 participants was conducted from birth; the results showed that participants with less fear of heights had more injuries because of falling.