Effects of melatonin and its relation to the hypothalamic-hypophyseal-gonadal axis

Selecting a pharmacotherapy regimen for patients with chronic insomnia

INTRODUCTION

Chronic insomnia, whether it is primary or in combination with another medical or psychiatric disorder, is a prevalent condition associated with significant morbidity, reduced productivity, increased risk of accidents, and poor quality of life. Pharmacologic and behavioral treatments have equivalent efficacy with each having its own advantages and limitations.

AREAS COVERED

The purpose of this perspective is to delineate the limitations encountered in implementing cognitive behavioral therapy (CBT) and to review the pharmacological treatments designed to target the different phenotypes of insomnia. The discussions address how to choose the optimal medication or combination thereof based on patients' characteristics, available medications, and the presence of comorbid conditions. Selective nonbenzodiazepine sedative 'Z-drug' hypnotics, melatonin receptor agonist-ramelteon, and low-dose doxepin are the agents of choice for treatment of primary and comorbid insomnia.

EXPERT OPINION

A pharmacological intervention should be offered if cognitive behavioral therapy for insomnia is not available or has failed to achieve its goals. Increasing evidence of the significant adverse consequences of long-term benzodiazepines should limit the prescription of these agents to specific conditions. Testing novel dosing regimens with a combination of hypnotic classes augmented with CBT deserve further investigation.

The assessment and management of insomnia: an update

Insomnia poses significant challenges to public health. It is a common condition associated with marked impairment in function and quality of life, psychiatric and physical morbidity, and accidents. As such, it is important that effective treatment is provided in clinical practice. To this end, this paper reviews critical aspects of the assessment of insomnia and the available treatment options. These options include both non-medication treatments, most notably cognitive behavioral therapy for insomnia, and a variety of pharmacologic therapies such as benzodiazepines, "z-drugs", melatonin receptor agonists, selective histamine H1 antagonists, orexin antagonists, antidepressants, antipsychotics, anticonvulsants, and non-selective antihistamines. A review of the available research indicates that rigorous double-blind, randomized, controlled trials are lacking for some of the most commonly administered insomnia therapies. However, there are an array of interventions which have been demonstrated to have therapeutic effects in insomnia in trials with the above features, and whose risk/benefit profiles have been well characterized. These interventions can form the basis for systematic, evidence-based treatment of insomnia in clinical practice. We review this evidence base and highlight areas where more studies are needed, with the aim of providing a resource for improving the clinical management of the many patients with insomnia.

Optimizing the Pharmacologic Treatment of Insomnia: Current Status and Future Horizons

A number of medications are available for treating patients with insomnia. These medications include agents approved as insomnia therapies by the U.S. Food and Drug Administration (FDA), agents approved by the FDA for another condition that are used "off-label" to treat insomnia, and agents available "over-the-counter" that are taken by individuals with insomnia. These agents differ in their properties, their safety and efficacy when used for different insomnia patient subtypes, and the available data on their efficacy and safety in these subtypes. As a result, optimizing the medication treatment of insomnia for a given patient requires that the clinician select an agent for use which has characteristics that make it most likely to effectively and safely address the type of sleep difficulty experienced by that individual. This article is intended to assist clinicians and researchers in carrying out this optimization. It begins by reviewing the basic characteristics of the medications used to treat insomnia. This is followed by a review of the fundamental ways that individuals with insomnia may differ and affect the choice of medication therapy. This review includes discussions that illustrate how to best choose a medication based on the characteristics of the available medications, the key differences among insomnia patients, and the available research literature. Lastly, we discuss future directions for the optimizing pharmacologic management of insomnia. It is hoped that the treatment tailoring methods discussed herein serve as a means of improving the clinical management of insomnia and, thus, improve the lives of the many patients who suffer from this common and impairing condition.

Protective effect of melatonin on liver ischemia reperfusion injury in rats

AIM: To investigate the effect of melatonin (Mel) on liver ischemia reperfusion (I/R) injury in rats.

METHODS: 150 male Wistar rats (190-210 g, 6-7weeks age) were divided into three groups at random: Mel exposure group, alcohol solvent control group and saline control group. The left branches of portal vein, hepatic artery, hepatic duct were blocked up for 60 min and then opened to establish liver I/R I models in rats. In each group, samples were collected in 0.5, 1, 6, 12, and 24 h after reperfusion respectively. 20 mg/kg of Mel was injected peritoneally in rats 30 min before experimentation in Mel exposure group. The duplicate concentration of alcohol and the same volume of saline were injected in control group as a substitution. Serum alanine aminotransferase (ALT) by auto biochemical analyzer, and superoxide dismutase (SOD) and terminal productions of lipid peroxidationin (MDA) in liver tissue were measured. Pathological changes in liver and immunohistochemical straining of ICAM-1 were determined with optical microscope.

RESULTS: The level of ALT measured in various time after reperfusion in Mel group was totally significantly lower than that in alcohol and saline control groups (P < 0.05). The level of MDA measured in 6 h, 12 h, and 24 h after reperfusion in Mel group was significantly lower than that in alcohol and saline control groups (P < 0.05). The level of SOD measured in 12, 24 h after reperfusion in Mel group was significantly higher than that in alcohol and saline control groups (P < 0.05). The expression level of ICAM-1 (%) measured in various time after reperfusion in Mel group was significantly lower than that in alcohol and saline control groups (P < 0.05).

CONCLUSION: Exotic Mel inhibits the activities of ALT, increases activities of superoxide dismutase (SOD), and decreases the cumulation of MDA in liver reperfusion tissue and expression of ICAM-1 in liver reperfusion tissue. Therefore, it can improve the hepatic function after reperfusion and plays a definitely protective role in liver I/R.