Analgesic effect of oxytocin receptor modulation in healthy volunteers

P.H. VUILLEUMIER; J. SCHLIESSBACH; J. A. BIURRUN MANRESA; M. MÜLLER; U. STAMER; L. ARENDT-NIELSEN; M. CURATOLO

Vienna

Congreso; 9th Congress of the European Pain Federation EFIC; 2015

European Pain Federation EFIC

Backgroundand aims: Oxytocin, a hypothalamic neuro-hormone involvedin parturition and breastfeeding, may also play a role in pain modulation via descending neuronal circuits projecting to lamina I-II of the spinal cord. Activation of glutamatergic and GABAergic interneurons at this level may cause pain inhibition. Additionally to GABAergic modulation, oxytocin can selectively block A-delta and C-fibers. Intrathecally administered oxytocin prevents long term potentiation, an important mechanism of enhanced central pain processing. The present study evaluates the analgesic effects of the oxytocin agonist carbetocin by multimodal pain testing. Methods: This is a randomized double-blinded placebo-controlled crossover study in 25 healthy male volunteers testing 0.1 mg intravenous carbetocin. The primary endpoint was intramuscular temporal summation threshold using electrical train-of-five stimulation at the tibialis anterior muscle. Secondary endpoints were different pain test modalities. This preliminary analysis shows results for the primary endpoint and for the area of secondary allodynia after intradermal capsaicin, analyzed by two-way RM ANOVA (with Bonferroni correction). Results: For the primary endpoint, there was no significant difference between carbetocin and placebo at any time (interactionp=0.6, fig. 1). The area of secondary allodynia was significantly lower with carbetocin, compared to placebo (jointp