text: In addition, some carbamates are used in human pharmacotherapy, for example, the acetylcholinesterase inhibitors neostigmine and rivastigmine, whose chemical structure is based on the natural alkaloid physostigmine. Other examples are meprobamate and its derivatives like carisoprodol, felbamate, mebutamate, phenprobamate, and tybamate, a class of anxiolytic and muscle relaxant drugs widely used in the 1960s before the rise of benzodiazepines, and still used nowadays in some cases. Carbachol is primarily used for various ophthalmic purposes.
  The protease inhibitor darunavir for HIV treatment also contains a carbamate functional group.
  Ephedroxane, an aminorex analogue used as a stimulant, also falls into the carbamate category.