Efficacy and safety of μ1-opioid receptor agonist (Taphalgin®) for emergency analgesia in outpatient practice

Background: A new peptide analgesic, a highly selective μ1-opioid receptor agonist (Taphalgin®) has shown the high efficacy in treating acute postoperative and chronic oncological pain, it appears to be a promising option for the treatment of patients with severe pain in outpatient clinics. Methods: Prospective observational study with a control period 4 hours after a single injection. The onset and peak of the analgesic effect, duration of effect, patient satisfaction and tolerability of therapy were assessed. Results: A total of 37 patients participated in the study. The pain intensity before the injection was 8.9 ± 1.2 according to numeric rating scale. Causes of severe pain included: radicular, oncologic and lumbar pain, vertebral fractures, joint injuries, tendon ruptures and others (e.g., hip fracture, nerve injury). Up to 95% of patients were already receiving pain therapy from non-steroidal anti-inflammatory drugs to strong opioids. After injection, pain intensity decreased with a peak at 30-45 minutes from 8.9±1.2 to 3.2±2.8 ( P ≤ 0.0001) points on numeric rating scale and lasted for more than 3 hours. There was no difference in pain intensity at rest and with movement. Adverse events were reported in 19 of 37 patients (51.3%). Most adverse events were non-serious, did not require treatment and resolved on their own. Conclusions: The μ1-opioid receptor agonist Taphalgin® demonstrates high efficacy, ease of use, rapid onset of effect and good tolerability in patients with severe pain syndrome in outpatient settings.