title: ABT-239
text: # ABT-239
  
  ABT-239 is an $H_3-receptor$ inverse agonist developed by Abbott. It has stimulant and nootropic effects, and has been investigated as a treatment for ADHD, Alzheimer's disease, and schizophrenia. ABT-239 is more active at the human $H_3$ receptor than comparable agents such as thioperamide, ciproxifan, and cipralisant. It was ultimately dropped from human trials after showing the dangerous cardiac side effect of QT prolongation, but is still widely used in animal research into $H_3$ antagonists / inverse agonists.
  
  