Hematoporphyrin is a chemical compound that is used in medical treatments and diagnostic procedures. However, there are several synonyms for this compound, including hematoporphyrin derivative (HPD), porfimer sodium, and photofrin. These terms are often used interchangeably in scientific and medical literature. HPD is a derivative of hematoporphyrin and has been used in the treatment of certain types of cancer. Porfimer sodium is a drug that is made from HPD and is used in photodynamic therapy. Photofrin is another drug made from HPD and is used in the treatment of certain cancers and other medical conditions. All of these compounds are related to hematoporphyrin and have similar properties and uses.