New research suggests that fMRI may have a role to play in evaluating the effectiveness of potential new painkillers and could allow “more effective and safer pain medications to reach patients who suffer from chronic pain sooner,” according to a press release from the American Society of Anesthesiologists (ASA).  

The release highlights the results of a recent study published in the ASA’s medical journal Anesthesiology that tested the ability of fMRI to measure the brain's neural response to pain. After administering various painkillers to the study participants, researchers applied capsaicin cream to the subjects’ skin to induce a phenomenon called central sensitization, then assessed the effects using fMRI.

“In the absence of behavioral measures distinguishing which drug was most effective at low subject numbers, the imaging responses were clear,” the ASA said. “Pain relevant neural activity was significantly reduced in the subjects who received gabapentin, even with extremely low subject numbers, highlighting the potential for fMRI to make a drug's effect clear in small cohorts.”

The finding could be an important step in preventing beneficial therapies from being discarded too early in the process of human drug development, according to the study’s lead author Vishvarani Wanigasekera, MD, of the University of Oxford, England, and colleagues.

"Many potential pain relieving drugs identified in preclinical research fail to reach the market because of a lack of early objective evidence that shows whether a drug is effectively reaching target pain receptors in the body and regulating chronic pain mechanisms," Wanigasekera said. "We have used noninvasive fMRI to successfully obtain such evidence that we hope can help to prevent the premature discarding of potentially effective pain relievers, as well as avoid exposing patients to ineffective ones."