The pro-convulsant drug pentylenetetrazol or PTZ has a fascinating history. PTZ's first medical uses in the 1920s predate the discovery of amphetamines. In the 1930s, it was used in psychiatric hospitals to deliberately induce seizures in people with schizophrenia. Decades later, it was advertised as a mild stimulant for the elderly, before being removed from the market as part of FDA reforms.
I did some research on PTZ for my upcoming book on idiopathic hypersomnia, because it was being tested in clinical trials for IH. Unfortunately Balance Therapeutics, the company that was developing the drug for Down syndrome and then IH, was dissolved, and it looks PTZ has come to a dead end. Read more about it here.