Etymology and pronunciation
The word prion, coined in 1982 by Stanley B. Prusiner, is derived from protein and infection, hence prion, and is short for "proteinaceous infectious particle", in reference to its ability to self-propagate and transmit its conformation to other proteins. Its main pronunciation is  (listen), although , as the homographic name of the bird (prions or whalebirds) is pronounced, is also heard. In his 1982 paper introducing the term, Prusiner specified that it is "pronounced pree-on". Prion protein
Structure
The protein that prions are made of (PrP) is found throughout the body, even in healthy people and animals. However, PrP found in infectious material has a different structure and is resistant to proteases, the enzymes in the body that can normally break down proteins. The normal form of the protein is called PrPC, while the infectious form is called PrPSc – the C refers to cellular PrP, while the Sc refers to scrapie, the prototypic prion disease, occurring in sheep. While PrPC is structurally well-defined, PrPSc is certainly polydisperse and defined at a relatively poor level. PrP can be induced to fold into other more-or-less well-defined isoforms in vitro, and their relationship to the form(s) that are pathogenic in vivo is not yet clear. PrPC
PrPC is a normal protein found on the membranes of cells, "including several blood components of which platelets constitute the largest reservoir in humans." It has 209 amino acids (in humans), one disulfide bond, a molecular mass of 35–36 kDa and a mainly alpha-helical structure.
Side effects
As with other opioid analgesics, central nervous system effects (such as sedation, confusion, and dizziness) are considerations with butorphanol. Nausea and vomiting are common. Less common are the gastrointestinal effects of other opioids (mostly constipation). Another side effect experienced by people taking the medication is increased perspiration. Name
Within the INN, USAN, BAN, and AAN naming systems this drug is known as butorphanol, while within JAN it is named torbugesic. As the tartrate salt, butorphanol is known as butorphanol tartrate (USAN, BAN).Its tradename Stadol was recently discontinued by the manufacturer. It is now only available in its generic formulations manufactured by Apotex, Mylan, Novex and Ben Venue Laboratories. Availability
Butorphanol is available in the U.S. as a generic drug; it is available in various nations under one of any number of trade names, including Moradol and Beforal (Brand name Stadol no longer available in the US); veterinary trade names include Butorphic, Dolorex, Morphasol, Torbugesic, and Torbutrol. Legality
Butorphanol is listed under the Single Convention on Narcotic Drugs 1961 and in the United States is a Schedule IV Narcotic controlled substance with a DEA ACSCN of 9720; being in Schedule IV it is not subject to annual aggregate manufacturing quotas. The free base conversion ratio of the hydrochloride is 0.69. Butorphanol was originally in Schedule II and at one point it was decontrolled. Veterinary use
In veterinary anesthesia, butorphanol (trade name: Torbugesic) is widely used as a sedative and analgesic in dogs, cats and horses.