5-Chloro-2-methyl-2,3,3a,12b-tetrahydrodibenzo(2,3:6,7)oxepino(4,5-c)pyrrole

Asenapine is a serotonin, dopamine, noradrenaline, and histamine antagonist in which asenapine possess more potent activity with serotonin receptors than dopamine. Sedation in patients is associated with asenapine's antagonist activity at histamine receptors. Its lower incidence of extrapyramidal effects are associated with the upregulation of D1 receptors. This upregulation occurs due to asenapine's dose-dependent effects on glutamate transmission in the brain. It does not have any significant activity with muscarinic, cholinergic receptors therefore symptoms associated with anticholinergic drug activity like dry mouth or constipation are not expected to be observed. Asenapine has a higher affinity for all aforementioned receptors compared to first-generation and second-generation antipsychotics except for 5-HT1A and 5-HT1B receptors.

Asenapine is an atypical antipsychotic multireceptor neuroleptic drug which shows strong 5HT2A (serotonin) and D2 (dopamine) receptor antagonism, which has been shown to enhance dopamine (DA) and acetylcholine (Ach) efflux in rat brains. Asenapine may improve cognitive function and negative symptoms in patients with schizophrenia.

Cmax, single 5 mg dose = 4 ng/mL (within 1 hour); Bioavailability, sublingual administration = 35%; Bioavailability, oral administration (swallowed) = <2%; Time to steady state, 5 mg = 3 days; Peak plasma concentration occurs within 0.5 to 1.5 hours. Doubling dose of asenapine results in 1.7-fold increase in maximum concentration and exposure. Drinking water within 2-5 minutes post administration of asenapine results in a decrease in exposure.

Urine (50%) and feces (50%)

20-25 L/kg