Acute mania
As for its efficacy in the treatment of acute mania, a recent meta-analysis showed that it produces comparatively small improvements in manic symptoms in patients with acute mania and mixed episodes than most other antipsychotic drugs (with the exception of ziprasidone) such as risperidone and olanzapine. Drop-out rates (in clinical trials) were also unusually high with asenapine. According to a post-hoc analysis of two 3-week clinical trials it may possess some antidepressant effects in patients with acute mania or mixed episodes. Adverse effects
Adverse effect incidenceVery common (>10% incidence) adverse effects include:

SomnolenceCommon (1-10% incidence) adverse effects include:

Weight gain
Increased appetite
Extrapyramidal side effects (EPS; such as dystonia, akathisia, dyskinesia, muscle rigidity, parkinsonism)
Sedation
Dizziness
Dysgeusia
Oral hypoaesthesia
Increased alanine aminotransferase
FatigueUncommon (0.1-1% incidence) adverse effects include:

Hyperglycaemia — elevated blood glucose (sugar)
Syncope
Seizure
Dysarthria
sinus bradycardia
Bundle branch block
QTc interval prolongation (has a relatively low risk for causing QTc interval prolongation.)
Pharmacology
Pharmacodynamics
Asenapine shows high affinity (pKi) for numerous receptors, including the serotonin 5-HT1A (8.6), 5-HT1B (8.4), 5-HT2A (10.2), 5-HT2B (9.8), 5-HT2C (10.5), 5-HT5A (8.8), 5-HT6 (9.5), and 5-HT7 (9.9) receptors, the adrenergic α1 (8.9), α2A (8.9), α2B (9.5), and α2C (8.9) receptors, the dopamine D1 (8.9), D2 (8.9), D3 (9.4), and D4 (9.0) receptors, and the histamine H1 (9.0) and H2 (8.2) receptors. It has much lower affinity (pKi < 5) for the muscarinic acetylcholine receptors. Asenapine behaves as a partial agonist at the 5-HT1A receptors. At all other targets asenapine is an antagonist. As of November 2010 asenapine is also in clinical trials at UC Irvine to treat stuttering. Even relative to other atypical antipsychotics, asenapine has unusually high affinity for the 5-HT2A, 5-HT2C, 5-HT6, and 5-HT7 receptors, and very high affinity for the α2 and H1 receptors. References
External links
"Asenapine". Drug Information Portal. U.S. National Library of Medicine. "Asenapine maleate". Drug Information Portal. U.S. National Library of Medicine.