Oxytocin
It has been shown that oxytocin differentially affects males and females. Females who are administered oxytocin are overall faster in responding to socially relevant stimuli than males who received oxytocin. Additionally, after the administration of oxytocin, females show increased amygdala activity in response to threatening scenes; however, males do not show increased amygdala activation. This phenomenon can be explained by looking at the role of gonadal hormones, specifically estrogen, which modulate the enhanced threat processing seen in females. Estrogen has been shown to stimulate the release of oxytocin from the hypothalamus and promote receptor binding in the amygdala.
Oxytrex
Oxytrex is an investigational drug currently in clinical trials. It combines the well known opioid agonist oxycodone in the treatment of pain with an ultra-low dose of naltrexone, an opioid antagonist. Naltrexone can have markedly different pharmacokinetics at ultra-low doses which may include, the attenuation of a pre-established opioid tolerance, the prevention of tolerance from the oxycodone in the formulation, and the possible amplification of oxycodone. It is being developed by "Pain Therapeutics, Inc." for the treatment of severe chronic pain.