Asenapine

Description

(±)-Asenapine is an atypical antipsychotic. It binds to dopamine D_1-4, α-adrenergic, and histamine receptors (K_is = 0.42-1.45, 0.32-1.26, and 1-6.17 nM, respectively), as well as the serotonin (5-HT) receptor subtypes 5-HT_1A, 5-HT_1B, 5-HT_2A, 5-HT_2B, 5-HT_2C, 5-HT_5A, 5-HT₆, and 5-HT₇ (K_is = 0.03-3.98 nM). (±)-Asenapine inhibits the suppression of neuron firing induced by the 5-HT_2A, dopamine D₂, and α₂-adrenergic receptor agonists 2,5-dimethoxy-4-iodoamphetamine (DOI), apomorphine, and clonidine , respectively, in rat brain (ED₅₀s = 75, 40, and 85 μg/kg, respectively). In vivo, (±)-asenapine (0.05-0.2 mg/kg, s.c.) increases extracellular dopamine levels in the medial prefrontal cortex (mPFC), nucleus accumbens (NAc), and lateral striatum and suppresses the conditioned avoidance response in rats. It prevents acute and chronic phencyclidine-induced deficits in cued reversal learning in rats when administered at a dose of 0.075 mg/kg. Formulations containing asenapine have been used in the treatment of schizophrenia and bipolar I disorder.

Chemical Properties

Yellow Oil

Uses

Combined serotonin (5HT2) and dopamine (D2) receptor antagonist; structurally related to Mianserin. Antipsychotic

Definition

ChEBI: (R,R)-asenapine is a 5-chloro-2-methyl-2,3,3a,12b-tetrahydrodibenzo[2,3:6,7]oxepino[4,5-c]pyrrole in which both of the stereocentres have R configuration. It is a conjugate base of a (R,R)-asenapine(1+). It is an enantiomer of a (S,S)-asenapine.

Biological Activity

Novel psychopharmacologic agent. Displays antagonist activity at 5-HT, dopamine, noradrenalin and histamine receptor subtypes (pK i values are 8.60, 8.40, 10.15, 9.75, 10.46, 8.84, 9.60, 9.94, 8.85, 8.90, 8.84, 9.38, 8.95, 8.93, 8.9, 9.49, 8.91, 9.00 and 8.21 for 5-HT 1A , 5-HT 1B , 5-HT 2A , 5-HT 2B , 5-HT 2C , 5-HT 5A , 5-HT 6 , 5-HT 7 , D 1 , D 2L , D 2S , D 3 , D 4 , α 1A , α 2A , α 2B , α 2C , H 1 and H 2 receptors respectively). Displays no appreciable affinity for muscarinic receptors. Exhibits potent activity in animal models predictive of antipsychotic efficacy.

Clinical Use

Atypical antipsychotic
Treatment of schizophrenia and bipolar disease

Enzyme inhibitor

This atypical antipsychotic agent (FW = 285.77 g/mol; CAS 65576-45-6), marketed under the trade names Saphris ?, and also known as Org 5222 and (3aRS,12bRS)-rel-5-chloro-2,3,3a,12b-tetrahydro-2-methyl-1H-dibenz[2,3: 6,7]-oxepino-[4,5-c]pyrrole, is multi-receptor antagonist with the following spectrum of binding interactions: serotonin 5-HT1A receptor, Ki = 2.5 nM; serotonin 5-HT1B receptor, Ki = 4.0 nM; serotonin 5-HT2A receptor, Ki = 0.06 nM; serotonin 5-HT2B receptor, Ki = 0.16 nM; serotonin 5-HT2C receptor, Ki = 0.03 nM; serotonin 5-HT5A receptor, Ki = 1.6 nM; serotonin 5-HT6 receptor, Ki = 1.5 nM; serotonin 5-HT7 receptor, Ki = 0.13 nM; a1- Adrenergic receptor, Ki = 1.2 nM; a2A-Adrenergic receptor, Ki = 1.2 nM; a2B-Adrenergic receptor, Ki = 0.25 nM; a2C-Adrenergic receptor, Ki = 1.2 nM; dopamine D1-receptor, Ki = 1.4 nM; dopamine D2-receptor, Ki = 1.3 nM; dopamine D3-receptor, Ki = 0.4 nM; dopamine D4-receptor, Ki = 1.1 nM; histamine H1-receptor, Ki = 1.0 nM; and histamine H2-receptor, Ki = 6 nM. Like other atypical antipsychotic drugs, asenapine preferentially enhances dopamine and acetylcholine efflux in the rat medial prefrontal cortex and hippocampus. See Reference-x for asenapine’s UV, IR, NMR, and mass spectra as well as X-ray analysis, thermal properties, solubilities and partition coefficient.

Drug interactions

Potentially hazardous interactions with other drugs
Anaesthetics: enhanced hypotensive effect.
Analgesics: increased risk of convulsions with tramadol; enhanced hypotensive and sedative effects with opioids.
Anti-arrhythmics: increased risk of ventricular arrhythmias with anti-arrhythmics that prolong the QT interval; avoid with amiodarone, disopyramide and procainamide (risk of ventricular arrhythmias).
Antidepressants: concentration possibly increased by fluvoxamine; possibly increased paroxetine concentration; concentration of tricyclics possibly increased.
Antiepileptics: antagonises anticonvulsant effect.
Antimalarials: avoid with artemether/lumefantrine.
Antivirals: concentration possibly increased by ritonavir.
Anxiolytics and hypnotics: increased sedative effects.

Metabolism

Metabolism is by direct glucuronidation by UGT1A4 and oxidative metabolism by cytochrome P450 isoenzymes (predominantly CYP1A2) are the primary metabolic pathways for asenapine.
Excretion is 50% renal and 50% via the faeces.