Repetitive daily oxytocin treatment reduces weight gain but not acute neonatal procedural pain.

Background: While the incidence of neonatal intensive care unit (NICU) admission steadily increases, neonatology lacks evidence of a safe, effective, and preventive analgesic for treating procedural pain. Given its role in nociception and promoting healthy neurodevelopment, the endogenous neuropeptide oxytocin (OT) emerges as a promising candidate.

Methods: This study investigates the use of daily repeated subcutaneous OT (1 mg/kg) treatment in an established model of neonatal repetitive procedural pain and assesses the effectivity of OT treatment on mechanical sensitivity and body weight.

Results: Contrary to our hypothesis repeated daily OT treatment did not prevent the development of mechanical hypersensitivity following needle pricks. Furthermore, treatment with OT diminished body weight gain in neonatal pups, a major side effect observed throughout the neonatal week. These results highlight the unique nature of the maturing nociceptive system that makes the identification and selection of analgesic options for the treatment of acute neonatal procedural pain a major challenge.

Conclusion: In conclusion, our preclinical results do not support the use of repeated OT for acute pain relief in the NICU, and the side effects on body weight gain raise concerns about the use of OT in the NICU.

Impact: Repeated daily OT treatment inhibits weight gain in neonatal rat pus. Repetitive daily OT administration does not prevent the development of mechanical hypersensitivity in a model of neonatal procedural pain. Future research must focus on the unique physiology of the developing nociceptive system to establish safe, effective and protective treatment of neonatal procedural pain.