In one study,dental patients who were given a placebo reported increased pain when they were also injected with:

Question

Quizplus · Accepted Answer

Naloxone is an opioid receptor antagonist that blocks the effects of opioids, including endogenous opioids such as enkephalins. Therefore, if patients were given a placebo and then injected with naloxone, any pain relief that they may have experienced from the endogenous opioids would be blocked, resulting in an increase in pain. Substance P and glutamate are neurotransmitters involved in pain perception, but they do not interact with the opioid system.

In One Study,dental Patients Who Were Given a Placebo Reported