Structure of the neuroleptic drug 4-amino-N-1-[(1-ethyl-2-pyrrolidinyl)methyl]-5-(ethylsulfonyl)-2- methoxybenzamide (amisulpride)

A pharmacological profile of intravenous amisulpride for the treatment of postoperative nausea and vomiting

INTRODUCTION

The issue of postoperative nausea and vomiting (PONV) remains important in surgical practice, contributing to patient distress, slower recovery, and increased use of healthcare resources. Many surgical patients report it to be a worse problem than the pain. New antiemetics of different classes are still needed to help manage PONV effectively, especially the treatment of established PONV after the failure of common prophylactic antiemetics such as 5-HT₃-antagonists and corticosteroids. Intravenous amisulpride, a drug with a long history of safe use in oral form as an antipsychotic, has recently been approved in the US (trade name: Barhemsys) as an intravenous antiemetic for the prevention and treatment of PONV.

AREAS COVERED

This review article summarizes the published data on the clinical pharmacology, safety, and efficacy of intravenous amisulpride as an antiemetic, supplemented by published data on oral amisulpride, where relevant to the intravenous form. Literature was obtained via the PubMed search terms 'intravenous amisulpride' and 'amisulpride AND safety.' Both primary and secondary pharmacology are covered, along with clinical pharmacokinetics (distribution, metabolism, and excretion). The review of clinical safety and efficacy includes data from four studies in the prevention of PONV, two in the treatment of PONV and two investigating effects on the QT interval of the electrocardiogram in healthy volunteers.

EXPERT OPINION

Given the importance of sufficient PONV prevention for patients and the healthcare system, the availability of intravenous amisulpride is helpful, restoring the dopamine-antagonist class as a potential mainstay in both combination prophylaxis and treatment.

Spectroscopic and computational study of the major oxidation products formed during the reaction of two quercetin conformers with a free radical

The goal of this research was to determine whether there are differences between the major oxidation products formed during the reaction of quercetin unhydrate (QUH) or quercetin dihydrate (QDH) with the 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH), as well as to identify some properties of these products. The study was carried out employing spectroscopic and computational methods, in order to know the effect of different conformations of quercetin on the mechanism of free radical scavenging. The results demonstrated that although the same oxidation products may be formed from QUH and QDH, their properties and the predominant product were different in each. The o-quinone was the predominant oxidation product of QUH, whereas in QDH it was established an equilibrium between o-quinone and extended p-quinone.

DFT study of quercetin activated forms involved in antiradical, antioxidant, and prooxidant biological processes

Quercetin, one of the most representative flavonoid compounds, is involved in antiradical, antioxidant, and prooxidant biological processes. Despite a constant increase of knowledge on both positive and negative activities of quercetin, it is unclear which activated form (quinone, semiquinone, or deprotonated) actually plays a role in each of these processes. Structural, electronic, and energetic characteristics of quercetin, as well as the influence of a copper ion on all of these parameters, are studied by means of quantum chemical electronic structure calculations. Introduction of thermodynamic cycles together with the role of coreactive compounds, such as reactive oxygen species, gives a glimpse of the most probable reaction schemes. Such a theoretical approach provides another hint to clarify which reaction is likely to occur within the broad range of quercetin biological activities.

Kinetic and stoichiometric assessment of the antioxidant activity of flavonoids by electron spin resonance spectroscopy

There is current interest in the use of naturally occurring flavonoids as antioxidants for the preservation of foods and the prevention of diseases such as atherosclerosis and cancers. To establish the molecular characteristics required for maximum antioxidant activity, electron spin resonance (ESR) spectroscopy has been used to determine the stoichiometry and kinetics of the hydrogen-donating ability of 15 flavonoids and d-alpha-tocopherol to galvinoxyl, a resonance-stabilized, sterically protected aryloxyl radical. The second-order reaction rates, which will be governed by O-H bond dissociation energies, were myricetin > morin > quercetin > fisetin approximately catechin > kaempferol approximately luteolin > rutin > d-alpha-tocopherol > taxifolin > tamarixetin > myricetin 3',4',5'-trimethyl ether > datiscetin > galangin > hesperitin approximately apigenin. Reactivity is highly dependant on the configuration of OH groups on the flavonoid B and C rings, there being little contribution from the A ring to antioxidant effectiveness. Highest reaction rates and stoichiometries were observed with flavonols capable of being oxidized to orthoquinones or extended paraquinones. However, rates and stoichiometries did not always correlate and the data suggest that kinetic factors may be of greater importance within a biological context.