Transcutaneous electrical nerve stimulation and opioid analgesia: Exploring a potential synergistic relationship.

Clinical analgesia requires balancing effective pain relief against opioid-related risks. Transcutaneous electrical nerve stimulation (TENS), a nonpharmacological and noninvasive modality, demonstrates synergistic potential with opioids, which may enhance analgesia, reduce opioid consumption, and minimize adverse effects. This review synthesizes evidence on TENS-opioid synergy, categorizes TENS modalities and parameters, and examines their interactive mechanisms. We discuss optimization strategies, including early TENS application, parameter individualization, and a "TENS + low-dose opioid" regimen. This combination represents a promising multimodal approach integrating pharmacological and nonpharmacological therapies, potentially improving outcomes while reducing opioid-related harms. Future work should prioritize rigorous pharmacological studies to confirm synergy, alongside multicenter trials, parameter optimization, development of intelligent personalized systems, and further mechanistic research to advance precision pain medicine.