Attention deficit hyperactivity disorder management
There are two major medications derived from methylphenidate's isomers: a racemic mixture of half d-threo-methylphenidate and half l-threo-methylphenidate called methylphenidate (Ritalin, Concerta), and an enantiopure formulation containing just d-threo-methylphenidate called dexmethylphenidate (Focalin).
Pregabalin
Pregabalin was synthesized in 1990 as an anticonvulsant. It was invented by medicinal chemist Richard Bruce Silverman at Northwestern University in Evanston, Illinois. Silverman is best known for identifying the drug pregabalin as a possible treatment for epileptic seizures. During 1988 to 1990, Ryszard Andruszkiewicz, a visiting research fellow, synthesized a series of molecules for Silverman. One looked particularly promising. The molecule was effectively shaped for transportation into the brain, where it activated L-glutamic acid decarboxylase, an enzyme. Silverman hoped that the enzyme would increase production of the inhibitory neurotransmitter GABA and block convulsions. Eventually, the set of molecules were sent to Parke-Davis Pharmaceuticals for testing. The drug was approved in the European Union in 2004. The US received FDA approval for use in treating epilepsy, diabetic neuropathic pain, and postherpetic neuralgia in December 2004. Pregabalin then appeared on the US market under the brand name" Lyrica" in fall of 2005. In 2017, FDA approved pregabalin extended-release "Lyrica CR" but unlike the immediate release formulation it was not approved for the management of fibromyalgia or as adjunctive therapy for adult patients with partial onset seizures.