A new peptide-based powerful painkiller as strong as morphine but with fewer side effects has been formulated. Using rats, scientists at Tulane University and Southeast Louisiana Veterans
Health Care System in US compared several engineered variants of the neurochemical endomorphin - found naturally in the body - to morphine to measure their effectiveness and side effects.
Usually, the peptide-based drugs target the same pain-relieving opioid receptor as morphine, for pain relief and can become addictive. Also, they can cause motor impairment and potentially fatal respiratory depression. Patients also build up tolerance over time, increasing the risk for abuse and overdose.
‘The new peptide-based drugs target pain-relieving receptors and show similar results to morphine without increasing the risk for abuse.’
Opium-based drugs are the leading treatments for severe and chronic pain, but they can be highly addictive. Their abuse results in thousands of overdose deaths in the US annually, researchers said.
"These side effects were absent or reduced with the new drug. It's unprecedented for a peptide to deliver such powerful pain relief with so few side effects," said lead investigator James Zadina, professor at the Tulane University School of Medicine.
In the study, the new endomorphin drug produced longer pain relief without substantially slowing breathing and showed normal motor co-ordination in rats. Though the drug is yet to be tested in humans, it showed no difference in behavior with regard to addiction while tested in rats.