Discontinuation of remifentanil, a potent, short-acting synthetic opioid analgesic drug brings about changes in pain processing in healthy men.
The research provides a plausible mechanism underlying increased pain sensitivity after discontinuation of opioid medication.
The imaging study of the brain and spinal cord was published in Journal of Neuroscience.
Dr. Sprenger and colleagues investigated changes in the brain and the spinal cord after application of the potent opioid remifentanil corresponding to increased sensitivity to heat pain stimuli applied to the forearm of healthy male adults.
Functional magnetic resonance imaging found altered signaling in a network that connects frontal brain regions via the brainstem with the spinal cord that has a crucial role in regulating pain.
Since remifentanil has a very short half-life and was mostly cleared from the blood when the changes occurred, these results cannot be attributed to direct effects of the drug.
Instead, they indicate altered pain processing in the central nervous system subsequent to opioid application.