Novel Drug Reverses Opioid-Induced Respiratory Depression While Preserving Pain Relief

Results from a pair of studies published in the September 2014 issue of Anesthesiology suggest a novel therapy developed by Galleon Pharmaceuticals Corp can reverse and prevent respiratory depression associated with opioid use without affecting analgesia.

“Although opioids such as oxycodone, methadone, and fentanyl are commonly used to manage perioperative and postoperative pain, opioids are associated with an increased risk of adverse effects, the most serious being respiratory depression,” said Albert Dahan, MD, PhD, lead author and professor of anesthesiology at Leiden University Medical Center, in a press release from the American Society of Anesthesiologists (ASA). “Opioid-induced respiratory depression can lead to brain damage, cardiac arrest, or death.”

According to the ASA, many patients who experience opioid-induced respiratory depression are prescribed drugs like naloxone (Narcan), which counteract the analgesic effect of an opioid, thus causing such patients to experience pain. Conversely, Galleon’s investigational agent, GAL-021, has been shown to reverse opioid-induced respiratory depression while maintaining pain relief in previous animal studies, and now human trials.

In those 2 human trials, Dr. Dahan and his co-authors examined a group of 12 male patients who received intravenous infusions of GAL-021 on top of alfentanil-induced respiratory depression, at which time their breathing capacity decreased by approximately 25%. Following the GAL-021 treatment, the participants showed an increase in respiratory rate with no adverse effects on pain relief or sedation.

“The development of potent painkillers that do not increase the risk of respiratory depression seems still far away, (so) using an add-on drug that reverses or prevents respiratory depression caused by opioid use, without affecting pain relief, is currently our best option to treat this condition,” Dr. Dahan noted. “While our data suggest that GAL-021 is an attractive alternative to other respiratory stimulants, additional studies are needed to further confirm these findings.”

Dr. Dahan and his colleagues also determined that GAL021 stimulated poikilocapnic ventilation during alfentanil administration without limiting sedation, antinociception, hemodynamics, or safety parameters.

“Our studies may be used to power future studies, which should address the ability of GAL021 to reverse respiratory depression at higher opioid concentrations and respiratory depression induced by other agents and drug combinations,” the study authors concluded. “Furthermore, its effect on nonrespiratory systems should be explored further.”