Clozapine N-oxide dihydrochloride

Clozapine N-oxide dihydrochloride is a major metabolite of Clozapine and a human muscarinic designer receptors (DREADDs) agonist. Clozapine N-oxide dihydrochloride specifically activates the DREADD receptor hM3Dq. Clozapine N-oxide dihydrochloride can cross the blood-brain barrier[1][2][3]. Clozapine is a potent dopamine antagonist and also a potent and selective muscarinic M4 receptor (EC50=11 nM) agonist[4][5].

Signaling Pathways >> Neuronal Signaling >> mAChR

Signaling Pathways >> GPCR/G Protein >> mAChR

Signaling Pathways >> GPCR/G Protein >> Dopamine Receptor

Signaling Pathways >> Neuronal Signaling >> Dopamine Receptor

Research Areas >> Neurological Disease

Human muscarinic designer receptors (DREADDs)[1]

Clozapine N-oxide (CNO) can bind to non-DREADD receptors at concentrations required for DREADD activation, and undergoes reverse-metabolism to its parent compound clozapine, an atypical antipsychotic that acts at a variety of pharmacological targets and produces numerous physiological and behavioral effects[2].

After a single intraperitoneal (i.p.) injection of Clozapine N-oxide (1 mg/kg) into mice, Clozapine N-oxide (CNO) plasma levels peak at 15 min and are very low after 2 h. Despite the short plasma half-life of CNO in mice, the biological effects that have been described after acute treatment of DREADD-expressing experimental animals are usually much longer (6-10 h)[1].

[1]. Wess J, et al. Novel designer receptors to probe GPCR signaling and physiology. Trends Pharmacol Sci. 2013 Jul;34(7):385-92.

[2]. Manvich DF, et al. The DREADD agonist clozapine N-oxide (CNO) is reverse-metabolized to clozapine and produces clozapine-like interoceptive stimulus effects in rats and mice. Sci Rep. 2018 Mar 1;8(1):3840.

[3]. van der Peet PL, et al. Gram scale preparation of clozapine N-oxide (CNO), a synthetic small molecule actuator for muscarinic acetylcholine DREADDs. MethodsX. 2018 Mar 23;5:257-267.

[4]. Silva RR, et al. Evaluation of Functional Selectivity of Haloperidol, Clozapine, and LASSBio-579, an Experimental Compound With Antipsychotic-Like Actions in Rodents, at G Protein and Arrestin Signaling Downstream of the Dopamine D2 Receptor. Front Pharmacol. 2019 Jun 4;10:628.

[5]. Zorn SH, et al. Clozapine is a potent and selective muscarinic M4 receptor agonist. Eur J Pharmacol. 1994 Nov 15;269(3):R1-2.