New painkiller could replace morphine, says study

SCIENTISTS last Wednesday (17) unveiled a synthetic drug that appears to neutralise pain as effectively as morphine, but without the side-effects that make opioids so dangerous and addictive.

The big-data methods used by the researchers also open up a promising avenue in drug innovation, they reported in the journal Nature.

In experiments with mice, the new compound – identified after screening “trillions” of candidates activated a known molecular pathway in the brain that triggers pain suppression.

But unlike morphine and prescription drugs such as oxycodone or oxycontin, it did not switch on a second pathway that can slow or block normal breathing.

Respiratory suppression caused by opioids results in some 30,000 deaths every year in the US alone, where opioid use and abuse has taken on epidemic proportions.

Nor did the new drug – dubbed PZM21 – produce addiction in the lab mice, which get hooked on morphine and pharmaceutical painkillers as easily as humans.

PZM21, the researchers summed up, offers “long-lasting analgesia coupled to apparent elimination of respiratory depression”. A third advantage of the new compound is it does not cause constipation.

Morphine – derived from the opium poppy – has remained the painkiller of choice, whether for post-op recovery or on the battlefield.

“But it is obviously dangerous too,” said Brian Shoichet, a professor at the University of California’s School of Pharmacy in San Francisco, and one of three senior authors of the study.

PZM21 still has many hurdles to overcome before showing up in pharmacies. It must be proven safe for humans, and effective in clinical trials, a process that typically takes up to a decade.

Future research will also need to determine whether mice – or people – develop a tolerance to the drug, causing it to lose its painkilling potency over time.