NFEPP (''N''-(3-fluoro-1-phenethylpiperidin-4-yl)-''N''-phenylpropionamide) is an analgesic

opioid Opioids are substances that act on opioid receptors to produce morphine-like effects. Medically they are primarily used for pain relief, including anesthesia. Other medical uses include suppression of diarrhea, replacement therapy for opioid use ...

chemical, similar in structure to

fentanyl Fentanyl, also spelled fentanil, is a very potent synthetic opioid used as a pain medication. Together with other drugs, fentanyl is used for anesthesia. It is also used illicitly as a recreational drug, sometimes mixed with heroin, cocain ...

, designed in 2016 by Spahn ''et al.'' from

Free University of Berlin The Free University of Berlin (, often abbreviated as FU Berlin or simply FU) is a public research university in Berlin, Germany. It is consistently ranked among Germany's best universities, with particular strengths in political science and t ...

to avoid the standard negative side effects of opiates, including

opioid overdose An opioid overdose is toxicity due to excessive consumption of opioids, such as morphine, codeine, heroin, fentanyl, tramadol, and methadone. This preventable pathology can be fatal if it leads to respiratory depression, a lethal condition that ca ...

, by only targeting

inflamed Inflammation (from la, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants, and is a protective response involving immune cells, blood vessels, and molecu ...

tissue.

Inflamed tissue

Inflamed tissue has a lower

pH value In chemistry, pH (), historically denoting "potential of hydrogen" (or "power of hydrogen"), is a scale used to specify the acidity or basicity of an aqueous solution. Acidic solutions (solutions with higher concentrations of ions) are ...

(~5–7) than non-inflamed tissue (7.4). Through computer simulation, scientists found a way to make the fentanyl analog only affect inflamed tissue via the addition of fluorine to the chemical structure. In experiment, it was shown that NFEPP produced injury-restricted analgesia in rats with different types of inflammatory pain without exhibiting typical opiate effects, including respiratory depression, sedation,

constipation Constipation is a bowel dysfunction that makes bowel movements infrequent or hard to pass. The stool is often hard and dry. Other symptoms may include abdominal pain, bloating, and feeling as if one has not completely passed the bowel movement ...

, and chemical seeking behavior. As a result, NFEPP has the potential to reduce

opioid addiction Opioid use disorder (OUD) is a substance use disorder characterized by cravings for opioids, continued use despite physical and/or psychological deterioration, increased tolerance with use, and withdrawal symptoms after discontinuing opioids. Op ...

and dependency, as there is no effect on users who are not actually suffering from pain, as the chemical does not interact with non-inflamed brain tissue until much higher doses are reached.

References

{{Opioidergics General anesthetics Synthetic opioids Piperidines Anilides Propionamides Mu-opioid receptor agonists Analgesics