Localised argyria often results from topical use of substances containing silver, such as some kinds of eye drops. Generalized argyria results from chronically swallowing or inhaling silver compounds, either for home medicinal purposes, or as a result of working with silver or silver compounds.While silver is potentially toxic to humans at high doses, the risk of serious harm from low doses, given over a short term, is small. Silver is used in some medical appliances because of its anti-microbial nature, which stems from the oligodynamic effect. Chronic ingestion or inhalation of silver preparations (especially colloidal silver) can lead to argyria in the skin and other organs. This is not life-threatening, but is considered by most to be cosmetically undesirable.The reference dose, published by the United States Environmental Protection Agency in 1991, which represents the estimated daily exposure that is unlikely to incur an appreciable risk of deleterious effects during a lifetime, is 5 µg/(kg·d).Argyria worsens and builds up as exposure to silver continues, and does not resolve once exposure stops. History
Since at least the mid-19th century, doctors have known that silver or silver compounds can cause some areas of the skin and other body tissues to turn grey or blue-grey. Argyria occurs in people who ingest or inhale silver in large quantities over a long period (several months to many years). People who work in factories that manufacture silver products can also breathe in silver or its compounds. In the past, some of these workers have become argyric.
In October 2011 Merck, now Merck-Serono, announced that they would give all rights to develop the compound back to Newron because they wanted to prioritise other projects and had corrected their estimates for safinamides market potential downwards.The US Food and Drug Administration (FDA) refused to file Newrons application in 2014 on formal grounds. Newron re-applied in December 2014. In spring 2015, following a commercial agreement between Newron and the Italian pharmaceutical company Zambon, the European Medicines Agency (EMA) approved the drug. In the following years, the drug has been launched in several European countries. Safinamide is the first antiparkinson medication to be approved for ten years. Safinamide was approved by US FDA in March 2017 for people with Parkinsons taking levodopa/carbidopa during "off" episodes. Research
Potential additional uses might be restless legs syndrome (RLS) and epilepsy. Safinamide was being tested in Phase II trials in 2008, but no results are available. When used as an adjunct to parkinsonian medication, safinamide was found to be efficacious in reducing pain in PD. References
External links
"Safinamide". Drug Information Portal. U.S. National Library of Medicine. "Safinamide mesylate". Drug Information Portal. U.S. National Library of Medicine.