The device delivers a subcutaneous injection of sumatriptan, without the use of a needle. Autoinjectors with needles have been previously available in Europe and North America.Phase III studies with an iontophoretic transdermal patch (Zelrix/Zecuity) started in July 2008. This patch uses low voltage controlled by a pre-programmed microchip to deliver a single dose of sumatriptan through the skin within 30 minutes. Zecuity was approved by the US FDA in January 2013. Sales of Zecuity have been stopped following reports of skin burns and irritation. Society and culture
Legal status
In the United States, it is available only by medical prescription. This requirement for a medical prescription also exists in Australia. However, it can be bought over the counter in the UK and Sweden.In Russia versions of sumatriptan, which are not registered in the National registry of medications, may be regarded as narcotic drugs (derivatives of dimethyltriptamine). Generics
Glaxo patents for sumatriptan expired in February 2009. At that time, Imitrex sold for about $25 a pill. Par Pharmaceutical then introduced generic versions of sumatriptan injection (sumatriptan succinate injection) 4- and 6-mg starter kits and 4- and 6-mg filled syringe cartridges, and 6-mg vials soon after.Mylan Laboratories Inc., Ranbaxy Laboratories, Sandoz (a subsidiary of Novartis), Dr. Reddys Laboratories, and other companies have been producing generic versions of sumatriptan tablets in 25-, 50-, and 100-mg doses. Generic forms of the drug are available in U.S. and European markets after Glaxos patent protections expired in the respective countries.
The genera most commonly associated with swimmers itch in humans are Trichobilharzia and Gigantobilharzia. It can also be caused by schistosome parasites of non-avian vertebrates, such as Schistosomatium douthitti, which infects snails and rodents. Other taxa reported to cause the reaction include Bilharziella polonica and Schistosoma bovis. In marine environments, especially along the coasts, swimmers itch can occur as well.These parasites use both freshwater snails and vertebrates as hosts in their parasitic life cycles as follows:

Once a schistosome egg is immersed in water, a short-lived, non-feeding, free-living stage known as the miracidium emerges. The miracidium uses cilia to follow chemical and physical cues thought to increase its chances of finding the first intermediate host in its life cycle, a freshwater snail. After infecting a snail, it develops into a mother sporocyst, which in turn undergoes asexual reproduction, yielding large numbers of daughter sporocysts, which asexually produce another short-lived, free-living stage, the cercaria. Cercariae use a tail-like appendage (often forked in genera causing swimmers itch) to swim to the surface of the water; and use various physical and chemical cues in order to locate the next and final (definitive) host in the life cycle, a bird. These larvae can accidentally come into contact with the skin of a swimmer. The cercaria penetrates the skin and dies in the skin immediately. The cercariae cannot infect humans, but they cause an inflammatory immune reaction. This reaction causes initially mildly itchy spots on the skin. Within hours, these spots become raised papules which are intensely itchy.