Chronic administration of buprenorphine in combination with samidorphan produces sustained effects in olfactory bulbectomised rats and Wistar-Kyoto rats

Burke, Nikita N, Li, Yan, Deaver, Daniel R, Finn, David P, Roche, Michelle, Eyerman, David J, Sanchez, Connie, Kelly, John P. (2019). Chronic administration of buprenorphine in combination with samidorphan produces sustained effects in olfactory bulbectomised rats and Wistar-Kyoto rats. Journal of Psychopharmacology, 33(12), 1620-1627. doi: 10.1177/0269881119872203

Abstract

Background: The combination of buprenorphine, a partial mu-opioid receptor agonist and a functional kappa-opioid receptor antagonist, with samidorphan, a functional mu-opioid receptor antagonist, is being developed as an adjunct therapy for major depressive disorder, in order to harness the mood-enhancing effects of opioids without unwanted side-effects such as a risk of addiction. Acute and subacute administration of the combination of buprenorphine and samidorphan is effective in reducing forced swim immobility in the Wistar-Kyoto rat, but the chronic effects have not been examined. Aims and methods: The purpose of this study was to assess if chronic (14-day) administration of buprenorphine (0.1 mg/kg, subcutaneous) alone or in combination with samidorphan (0.3 mg/kg, subcutaneous) maintains antidepressant-like activity in the olfactory bulbectomised rat model and the Wistar-Kyoto rat, two models that exhibit ongoing behavioural deficits in tests commonly used to study effects of antidepressants. Results: Olfactory bulbectomised-induced hyperactivity was attenuated by chronic administration of buprenorphine alone and in combination with samidorphan, to that of sham control activity levels. Neither buprenorphine nor samidorphan altered stress-associated defecation in sham or olfactory bulbectomised rats in the open field. In Wistar-Kyoto rats, buprenorphine alone significantly reduced forced swim immobility and increased locomotor activity three hours post-final dosing. Buprenorphine plus samidorphan significantly reduced forced swim immobility without changing locomotor activity at this time point. Buprenorphine alone also significantly reduced forced swim immobility 24 h post-final dosing. Conclusion: Chronic treatment of buprenorphine alone or buprenorphine plus samidorphan is effective in reversing behavioural deficits in distinct non-clinical paradigms. These non-clinical results complement the antidepressant effect of this combination observed in clinical studies.

Funder

Alkermes Inc.

Publisher

SAGE Publications

Rights

Attribution-NonCommercial-NoDerivs 3.0 Ireland

cbn

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Physiology (Scholarly Articles)