Neostigmine methylsulfate is a medication used in the treatment of myasthenia gravis. The medication works by helping the connection between nerve impulses and muscle movement. The medication comes in the form of an injectable liquid and is usually given in a hospital or doctor's office. If you use the medication at home, you will be trained on how to properly give yourself a dose. Neostigmine methylsulfate is the generic name of this medication. The brand names are Prostigmin Bromide or Prostigmin. The medication is only available by prescription.