Effects of intranasal oxytocin on pain perception among human subjects: A systematic literature review and meta-analysis

• Published in: Hormones and behavior Vol. 147; p. 105282
• Main Authors: Lopes, Samuel, Osório, Flávia de Lima
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.2023
• Subjects: Administration, Intranasal; Analgesia; Human subjects; Humans; Nociception; Oxytocin; Oxytocin - pharmacology; Oxytocin - therapeutic use; Pain - drug therapy; Pain perception; Pain Perception - drug effects; Nociception; Human subjects; Analgesia; Pain perception; Oxytocin
• ISSN: 0018-506X; 1095-6867; 1095-6867
• DOI: 10.1016/j.yhbeh.2022.105282

Oxytocin (OXT) is a peptide hormone produced in the hypothalamus that plays a neuromodulatory role in emotion, stress, and anxiety. Due to its multidimensional role, OXT is a promising target for therapeutic interventions to treat pain. Perform a systematic literature review, followed by a meta-analysis to identify the effects of intranasal OXT on the self-perception of clinical and experimental pain among human subjects. A systematic review was conducted in the PubMed, PsycINFO, Scielo, Lilacs, and Web of Science databases, using the keywords Oxytocin, Pain, Analgesia, and Nociception. Fifteen papers were included in the meta-analysis. None of the outcomes presented statistical significance in terms of the interventions' effect size: pain intensity (SMD = −0.02 (CI 95 %: −0.14 to 0.10; p = 0.76)) and pain unpleasantness (SMD = -0.15 (CI 95 %: −0.34 to 0.04; p = 0.12)). No meta-analysis was performed for pain threshold or tolerance because few papers address these outcomes. There was no statistically significant effect of intranasal OXT administration on pain perception, considering equivalence limits between (−0.2 and 0.2). However, it must be considered that the study designs may not have been sensitive enough to detect minor analgesic effects of OXT, which, being weak, may also not be perceived at a conscious level. Additionally, OXT effects possibly depend on specific characteristics of the painful condition, such as pain complexity, intensity, and duration, contextual variables like the presence of social and affective support, and individual characteristics. [Display omitted] •The oxytocin intranasal administration did not directly affect pain perception.•The potential analgesic effect on human may be weak to conscious level perception.•The characteristics of the painful condition may affect the effects of oxytocin.•The social and affective support can potentiate the effect of oxytocin on pain.