History
Since the synthesis of 5-fluorouracil (5-FU) in 1957, fluoropyrimidines have been used to treat many types of cancer. Due to the drawbacks of 5-FU therapy, such as having to be administered over long periods of time via intravenous infusion and the development of resistance in tumors, more convenient and efficacious fluoropyrimidine therapy has been desired. The fluoropyrimidine component of this drug, trifluridine, was first synthesized in 1964 by Heidelberger et al.By the late 1960s, Phase I and Phase II clinical trials of intravenous trifluridine alone initially proved to be disappointing. Its pharmacokinetic profile during these clinical trials showed that the drug exhibited a very short half-life while in serum (12 minutes post-injection). Adjustments in the dosing regimen improved its effects in small studies, but the effect was short-lived.Researchers later found out that trifluridine, when taken orally, was broken down into the inactive metabolites 5-trifluoromethyluracil and 5-trifluoromethyl-2,4(1H,3,H)-pyrimidinedione (FTY) during its extensive first pass metabolism in the liver via the enzyme thymidine phosphorylase. It was then hypothesized that orally administered FTD concentrations could be increased and maintained if the drug was given with a thymidine phosphorylase inhibitor.Trifluridine/tipiracil was approved by the U.S. FDA in September 2015, and by the European Medicines Agency in April 2016. References
External links
"Tipiracil hydrochloride mixture with trifluridine". Drug Information Portal. U.S. National Library of Medicine.
Psorosperm (from the Greek ψωρα itch and σπερμα seed) is a former name of a number of parasitic protozoa that produce cystlike or sporelike structures in the tissue of hosts. The term is now essentially obsolete. Some that affect vertebrate hosts are now called coccidia. Others, such as the cause of pébrine in silkworms, are now recognized as microsporidians, and some are myxosporidians. The genus Psorospermium (which includes the species Psorospermium haeckeli) itself is a parasite of crayfishes, and belongs to an enigmatic group of unicellular organisms that some biologists think may be related to the common ancestors of animals and fungi.J. Müller introduced the term in German (as Psorospermien) in 1841.Psorosperm was at one point believed to be the cause of Dariers disease. "Psorospermiasis" is classified under 136.4 in ICD-9. == References ==