Neuropathic Pain: This Drug Could Reduce the Need for Opioids

Pharmacologic approaches are still "the most widely used therapeutic options to ameliorate persistent pain," according to this overview from UpToDate. But with growing awareness of the potential negative outcomes associated with long-term opioid therapy, a newly discovered approach may be just what the doctor ordered.

Pharmacologic approaches are still “the most widely used therapeutic options to ameliorate persistent pain,” according to this overview from UpToDate. But with growing awareness of the potential negative outcomes associated with long-term opioid therapy, a newly discovered approach may be just what the doctor ordered.

There are many reasons why relieving pain without relying solely on opioids is important. For one, they are highly addictive. One in four patients with a prescription will end up moving on to long-term use and half of adolescents misuse the drugs. Also, recent research indicates that opioids may not even be effective for long-term pain management in neuropathy. So whichever way you look at it, alternative treatments for neuropathic pain are needed and researchers may have just found one.

“Opioid receptor agonists, such as morphine and oxycodone are highly effective strong analgesics for relief of moderate or severe pain. However, morphine is less effective in treating neuropathic pain,” the authors explained in the Journal of Biomedical Science.

Oxycodone is one of the only opioids that is better equipped to relieve neuropathy. To supplement for the lack of relief from certain prescriptions, the team explored the use of dextromethorphan (DM), an N-methyl-D-aspartate receptor antagonist with neuroprotective properties, in combination with a lower dose of oxycodone.

DM has been used to relieve coughing for over 50 years. So what makes the researchers think that it would be effective in pain management?

“Our previous studies showed that DM could effectively reduce the rewarding effects (i.e., addiction potential) and drug-seeking effects of morphine or methamphetamine in rats,” they confirmed. “DM also has important neuroprotective properties in various CNS injury models, including ischemia, seizure, and traumatic brain injury paradigms.”

Mice with spinal nerve injury were treated with either just oxycodone or an oxycodone-DM combo twice per day for one to 13 days. Those who were only given 1 mg/kg of oxycodone had partial pain improvement. However, administering 10 mg/kg of DM enhanced the acute effect of 1 mg/kg of oxycodone a substantial amount. The authors noted, however, that the same could only be said about the chronic effect of oxycodone when paired with a 3 mg/kg dose.

Chronic oxycodone treatment suppresses the activation of glial cells (astrocytes and microglia) — which are sources of pain. Another finding from the study indicated that the oxycodone-DM combo was able to better suppress the activation when compared to oxycodone on its own.

“The combination of DM with oxycodone may lower the dose of oxycodone and decrease the side effects of oxycodone,” the team concluded, “therefore providing beneficial effects in early treatment of neuropathic pain.”

If there was ever a time to get behind opioid alternatives, this is it.