In botany, the term is most common in its adjectival forms, where it is used in binomial names to refer to species that are distinguished by hollow or tubular structures. Monarda fistulosa, for example, has tubular flowers. The term was first used in the 14th century. Definition
A fistula is an abnormal connection between vessels or organs that do not usually connect. It can be due to a disease or trauma, or purposely surgically created. Classification
Various types of fistulas include:

Blind: Only one open end; may also be called sinus tracts. Complete: Both internal and external openings. Incomplete: An external skin opening that does not connect to any internal organ.Although most fistulas are in forms of a tube, some can also have multiple branches. Location
Types of fistula can be described by their location. Anal fistulas connect between the epithelialized surface of the anal canal and the perianal skin. Anovaginal or rectovaginal fistulas occur when a hole develops between the anus or rectum and the vagina. Colovaginal fistulas occur between the colon and the vagina. Urinary tract fistulas are abnormal openings within the urinary tract or an abnormal connection between the urinary tract and another organ such as between the bladder and the uterus in a vesicouterine fistula, between the bladder and the vagina in a vesicovaginal fistula, and between the urethra and the vagina in urethrovaginal fistula.
Icatibant, sold under the brand name Firazyr, is a medication for the symptomatic treatment of acute attacks of hereditary angioedema (HAE) in adults with C1-esterase-inhibitor deficiency. It is not effective in angioedema caused by medication from the ACE inhibitor class.It is a peptidomimetic consisting of ten amino acids, which is a selective and specific antagonist of bradykinin B2 receptors. Mechanism of action
Bradykinin is a peptide-based hormone that is formed locally in tissues, very often in response to a trauma. It increases vessel permeability, dilates blood vessels and causes smooth muscle cells to contract. Bradykinin plays an important role as the mediator of pain. Surplus bradykinin is responsible for the typical symptoms of inflammation, such as swelling, redness, overheating and pain. These symptoms are mediated by activation of bradykinin B2 receptors. Icatibant acts as a bradykinin inhibitor by blocking the binding of native bradykinin to the bradykinin B2 receptor. Little is known about the effects of icatibant on the bradykinin B1 receptor. Society and culture
Legal status
Icatibant received orphan drug status in Australia, the EU, Switzerland, and the US for the treatment of hereditary angioedema (HAE).In the EU, the approval by the European Commission (July 2008) allows Jerini to market Firazyr in the European Unions 27 member states, as well as Switzerland, Liechtenstein and Iceland, making it the first product to be approved in all EU countries for the treatment of HAE. In the US, the drug was granted FDA approval on August 25, 2011. References
External links
"Icatibant". Drug Information Portal. U.S. National Library of Medicine. "Icatibant acetate".