The rising prevalence of early-life
opioid exposure has become a pressing public health issue in the U.S. Neonates exposed to
opioids in utero are at risk of experiencing a constellation of postpartum
withdrawal symptoms commonly referred to as neonatal
opioid withdrawal syndrome (NOWS).
Buprenorphine (BPN), a partial agonist at the
mu-opioid receptor (MOR) and antagonist at the
kappa-opioid receptor (KOR), is currently approved to treat
opioid use disorder in adult populations. Recent research suggests that BPN may also be effective in reducing
withdrawal symptoms in neonates who were exposed to
opioids in utero. We sought to determine whether BPN attenuates somatic withdrawal in a mouse model of NOWS. Our findings indicate that the administration of
morphine (10mg/kg, s.c.) from postnatal day (PND) 1-14 results in increased
somatic symptoms upon
naloxone-precipitated (1mg/kg, s.c.) withdrawal. Co-administration of BPN (0.3mg/kg, s.c.) from PND 12-14 attenuated symptoms in
morphine-treated mice. On PND 15, 24h following
naloxone-precipitated withdrawal, a subset of mice was examined for thermal sensitivity in the hot plate test. BPN treatment significantly increased response latency in
morphine-exposed mice. Lastly, neonatal
morphine exposure elevated
mRNA expression of KOR, and reduced
mRNA expression of
corticotropin-releasing hormone (CRH) in the periaqueductal gray when measured on PND 14. Altogether, this data provides support for the
therapeutic effects of acute low-dose
buprenorphine treatment in a mouse model of neonatal
opioid exposure and withdrawal.