Naloxone fails to affect short-term memory in man

The effects of naloxone on memory were studied in 26 healthy male volunteers. Either placebo, or 10 mg, or 20 mg of naloxone was given iv on separate occasions. Ten minutes after each injection, the subjects listened to 8 lists of words (10 words on each list). Immediate recall, delayed recall, and delayed recognition were not affected by naloxone within 60 minutes of its administration. These results provide no support for the hypothesis that edorphins play a role in the short-term auditory memory in man.