Discovery and development of an oral analgesic targeting the α2B adrenoceptor

M Masayasu Toyomoto (Department of Drug Discovery Medicine, Graduate School of Medicine, Kyoto University) T Takashi Kurihara (Department of Pharmacology, Graduate School of Medical and Dental Sciences, Kagoshima University) T Takayuki Nakagawa (Department of Clinical Pharmacology and Pharmacotherapy, School of Pharmaceutical Sciences, Wakayama Medical University) A Asuka Inoue R Ryo Kimura (Department of Anatomy and Developmental Biology, Graduate School of Medicine, Kyoto University) I Isao Kii (Department of Anatomy and Developmental Biology, Graduate School of Medicine, Kyoto University) T Teruo Sawada (Department of Anatomy and Developmental Biology, Graduate School of Medicine, Kyoto University) T Takashi Ogihara (Department of Clinical Pharmacology and Therapeutics, Kyoto University Hospital) K Kazuki Nagayasu (Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University) T Takayuki Kishi (Molecular and Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Tohoku University,) H Hiroshi Onogi (Department of Anatomy and Developmental Biology, Graduate School of Medicine, Kyoto University) D Dohyun Im (Department of Cell Biology, Graduate School of Medicine, Kyoto University) H Hidetsugu Asada (Department of Cell Biology, Graduate School of Medicine, Kyoto University) S So Iwata J Jumpei Taguchi (Laboratory for Biomaterials and Bioengineering, Institute of Integrated Research, Institute of Science Tokyo) Y Yuto Sumida (Laboratory for Biomaterials and Bioengineering, Institute of Integrated Research, Institute of Science Tokyo) S Suguru Yoshida (Department of Energy and Hydrocarbon Chemistry) J Junken Aoki (Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo) T Takamitsu Hosoya (Chemical Bioscience Team, Laboratory for Biomaterials and Bioengineering, Institute of Integrated Research, Institute of Science Tokyo, Chiyoda-ku, Tokyo 101-0062, Japan) M Masatoshi Hagiwara (Department of Drug Discovery Medicine, Graduate School of Medicine, Kyoto University)

Abstract

Noradrenaline is a major monoaminergic neurotransmitter involved in pain modulation through an α2A-adrenergic receptor. Hence, α2-adrenergic agonists such as clonidine and dexmedetomidine exhibit analgesic and opioid-sparing effects. However, their use is restricted to hospital settings due to potential risks of acute hypertension/hypotension and bradycardia. Here, we report that ( Z )-1-(3-ethyl-5-fluorobenzo[ d ] thiazol-2(3 H )-ylidene)propan-2-one [adrenergic inducer of analgesia (ADRIANA)], a newly identified α2B subtype-specific antagonist, specifically promotes noradrenaline release in the murine spinal dorsal horn and produces analgesic effects by stimulating the α2A-dependent pain inhibitory pathway. Orally administered ADRIANA has potent analgesic effects in several nociceptive pain models of mice and nonhuman primates without cardiovascular effects. Mice with genetic loss of the α2B adrenoceptor showed normal responses to mechanical pain, but the analgesic effect of ADRIANA was not significantly detected. These findings reveal that the α2B adrenoceptor is a promising target for nonopioid analgesics through the activation of the α2A-dependent descending pathway.

Article Details

Volume / Issue Vol. 122, Issue 32
Published August 12, 2025
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (20)

M

Masayasu Toyomoto

Department of Drug Discovery Medicine, Graduate School of Medicine, Kyoto University

T

Takashi Kurihara

Department of Pharmacology, Graduate School of Medical and Dental Sciences, Kagoshima University

T

Takayuki Nakagawa

Department of Clinical Pharmacology and Pharmacotherapy, School of Pharmaceutical Sciences, Wakayama Medical University

A

Asuka Inoue

R

Ryo Kimura

Department of Anatomy and Developmental Biology, Graduate School of Medicine, Kyoto University

I

Isao Kii

Department of Anatomy and Developmental Biology, Graduate School of Medicine, Kyoto University

T

Teruo Sawada

Department of Anatomy and Developmental Biology, Graduate School of Medicine, Kyoto University

T

Takashi Ogihara

Department of Clinical Pharmacology and Therapeutics, Kyoto University Hospital

K

Kazuki Nagayasu

Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University

T

Takayuki Kishi

Molecular and Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Tohoku University,

H

Hiroshi Onogi

Department of Anatomy and Developmental Biology, Graduate School of Medicine, Kyoto University

D

Dohyun Im

Department of Cell Biology, Graduate School of Medicine, Kyoto University

H

Hidetsugu Asada

Department of Cell Biology, Graduate School of Medicine, Kyoto University

S

So Iwata

J

Jumpei Taguchi

Laboratory for Biomaterials and Bioengineering, Institute of Integrated Research, Institute of Science Tokyo

Y

Yuto Sumida

Laboratory for Biomaterials and Bioengineering, Institute of Integrated Research, Institute of Science Tokyo

S

Suguru Yoshida

Department of Energy and Hydrocarbon Chemistry

J

Junken Aoki

Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, The University of Tokyo

T

Takamitsu Hosoya

Chemical Bioscience Team, Laboratory for Biomaterials and Bioengineering, Institute of Integrated Research, Institute of Science Tokyo, Chiyoda-ku, Tokyo 101-0062, Japan

M

Masatoshi Hagiwara

Department of Drug Discovery Medicine, Graduate School of Medicine, Kyoto University