Sleep disorders and hypnotic agents: medical, social and economical impact

Insomnia is a subjective complaint relating to approximately 30% of the adult population in France, described by the patient as a difficulty of initiating and/or maintaining sleep. Its prevalence increases with age and sex: women are more affected than men (24% vs 14%). Insomnia is either occasional (20%), or chronic (10%). Chronic insomnia has an important impact on patients' everyday life e.g. fatigue, perturbed diurnal waking state, impaired quality-of-life... which results in lower work productivity and drowsiness as well as relational difficulties, absenteeism. About 80% of patients consult their general practitioner first. The aim of a hypnotic agent is to obtain sleep as physiological as possible. Benzodiazepines and benzodiazepines-like agents (zopiclone, zolpidem, zaleplon) are the most widely used hypnotics. However, their indications must be limited to occasional insomnia with a limited duration: less than four weeks. There is no advantage with using a combination of hypnotic agents, a practice which should be prohibited. Adverse effects can be serious, e.g. diurnal somnolence associated with risks of road accidents and, in the elderly, the risk of falls. After chronic use, hypnotics can be addictive, as their effects wear off in three to four weeks. After withdrawal, insomnia rebound is frequent. Use of hypnotics in association with alcohol is a well-known drug-addiction behavior. According to the French health insurance fund, 9% of the general population use hypnotics and about half of them regularly. Insurance refunds for hypnotics and sedatives reach more than 110 million euros annually. The efficiency of hypnotics wears off, quickly for benzodiazepines (three - four weeks), or less quickly for zopiclone and zolpidem (a few months). Insomnia is a major public health issue, each year 10% of the incident cases of insomnia treated by hypnotics joint the group of subjects with chronic insomnia. This failure to treat insomnia properly can be explained, at least in part, by several insufficiencies: physicians and pharmacists training, medical profession awareness, research, public information on the rules of good sleep (public health campaigns, booklets, role of physicians and the pharmacists).     

Dysfunctions of biological clocks and their treatments

Biological rhythms are periodic phenomena entrained to environmental changes by exogenous factors called synchronizers or entraining agents namely the light-dark cycle, the rest-activity cycle and the seasons, among others. In humans the major synchronizers are the light-dark and rest activity cycles. The endogenous component of a biological rhythm is dependent upon a number of clock genes. The main biological clock (oscillator or pacemaker) is the suprachiasmatic nucleus (SCN) of the anterior hypothalamus. The photoperiod (light-dark cycle) perceived by the retina acts on the SCN genes. Peripheral clocks have also been described in a number of tissues e.g. retina, adrenals. In a number of occurrences the synchronizers are badly perceived (transmeridian flights, shiftwork, nightwork...) or are not at all perceived (blindness). This situation is named rhythm desynchronization, it is external when the desynchronization is strictly related to the environment or internal when it is related to a dysfunction of the clock like in e.g. aging, Alzheimer disease, seasonal affective disorders (SAD) or hormone-dependent cancers which results in fatigue, sleep and mood disorders... A number of drugs called resynchronizing agents or chronobiotics which act on the biological clock are able to resynchronize the clock and to improve the patients' condition. Bright light is used in the treatment of SAD, melatonin, the pineal hormone, is also of interest when administered at precise timings in the 24hours scale. Other drugs like B12 vitamin or psychotropic drugs have also been proposed as chronobiotics.     

Melatoninergic receptor agonists and antagonists: pharmacological aspects and therapeutic perspective

Melatonin, or N-acetyl 5-methoxytryptamine, a neurohormone produced in the pineal gland during periods of darkness, plays a key role in the regulation of circadian and seasonal biological rhythms. In mammals, specific MT1 and MT2 receptors are located in the central nervous system, mainly in suprachiasmatic nuclei, and also in a number of peripheral sites. Besides its chronobiotic action on light-dependant functions, such as sleep/waking alternance or seasonal depression, melatonin exerts modulatory effects on immune, endocrine and metabolic functions. However, its short half-life and extensive metabolism lead to a poor bioavailability. This prompted to search for metabolically stable analogs displaying new and innovative properties. The S 20098 compound, a melatoninergic agonist, has proven potent antidepressive and anxiolytic actions. The S 20928 compound, a melatonin antagonist, was shown to enhance basal metabolism and reduce weight gain. Thus, both of these melatonin derivatives open perspectives for the development of innovative therapeutic agents in the fields of depression and obesity.     

Normal and disordered sleep

Normal sleep is a complex and reversible state of brain functioning, including reduced inputs and outputs, blunted reflexes, and metabolic and cognitive changes. Evidence supports a role for sleep in the consolidation of an array of learning and memory tasks. Sleep deprivation and fragmentation result in executive dysfunction, increased appetite/weight and cellular stress. Sleep is a vital, complex but plastic function that can be modulated depending on individual heritage and motivation. The major role of sleep in attention and memory raises about concern the reduction in sleep duration recently pointed in teenagers and young adults. Sleep disorders are numerous and various. Their mechanism is not always identified, but may result from a central dysfunction in sleep-wake (e.g. narcolepsy) or circadian (e.g. advanced sleep phase syndrome) systems, from the sleep-related loss of compensation of reflexes normally effective during wakefulness (breathing is the most vulnerable function during sleep), or from other diseases preventing sleep (e.g. psychiatric insomnia, restless legs syndrome).     

Sleep deprivation deficits and their reversal by d-and l-amphetamine

Vigilance performance, waking EEG patterns and mood were studied before and after one night of sleep deprivation in normal males. The effects of d-amphetamine 10 mg, l-amphetamine 10 mg and placebo on these measures were compared. Changes were found in all three measures after one night of sleep-deprivation. d-Amphetamine was more powerful than l-amphetamine in reversing sleep deprivation effects on vigilance and on waking EEG.     

Efficacy of caffeine and modafinil in counteracting sleep deprivation in the marmoset monkey

Background and purpose The effects of sleep deprivation are a burden in our 24-h society. The use of wake-promoting compounds could improve the performance in situations where sleep cannot be allowed. In this study, the efficacy of the wake-promoting compounds, modafinil and caffeine, in counteracting the effects of 24-h sleep deprivation in the marmoset monkey were tested. As caffeine is habitually used, the efficacy of both compounds after short- and long-term use was investigated. Materials and methods After a normal active day, the animals were kept awake and received wake-promoting compounds during the whole night. Three times during the sleep-deprived night, putative fatigue was assessed with an activity test and the vigilance and ability to execute a task was assessed with a hand–eye coordination (HEC) task. Results Both compounds were able to counteract to some extent the decline in performance. Modafinil was able to keep the activity at baseline performance, but performance on the HEC task was not improved. Caffeine was able to keep performance in the HEC task at a level just below daytime level but was not able to keep activity at daytime levels during the last part of the night. Caffeine and modafinil administration for 2 weeks showed a comparable effect on activity as acute use. The performance on the HEC task was similar after chronic caffeine and improved after chronic modafinil. Conclusion It is therefore concluded that modafinil and caffeine were both able to postpone or prevent the decline in vigilance and psychomotor performance and increase in fatigue induced by sleep deprivation.     

Sleep and hypnotic drugs.

In recent years the effectiveness of hypnotic drugs has had to be assessed in terms of a greatly increased knowledge of the physiology and pathology of sleep. The normal pattern of sleep and wakefulness involves a cyclic alternation between three rather than two basically dissimilar states of the brain and body - alert wakefulness, rapid-eye-movement (REM) sleep and non-rapid-eye-movement (NREM) sleep. The pattern of this alternation in individual people results from the interaction of many influences - biological (including genetic, early developmental and later degenerative influences), psychological, social and environmental factors, various physical and psychiatric disorders, and most drugs which affect the central nervous system. The quality of sleep is not related in any simple or constant manner either to its duration or to the proprotions of time spent in each stage of sleep. Among the disorders of sleep, insomnia is a far more common problem of medical management than are enuresis, narcolepsy, somnambulism or nightmares. With a few exceptions, most hypnotic drugs now in widespread use cease to be effective in treating insomnia after the first few nights. However, the ineffective treatment is often continued because insomnia will be even worse during the initial period of drug withdrawal. These factors and the toxicity of hypnotic drugs when taken in overdose make the long-term treatment of insomnia more difficult than was previously supposed. Barbiturates should no longer be prescribed. Some of the non-barbiturates, such as glutethimide and methaqualone, have no advantage over the barbiturates. The benzodiazepine hypnotics, nitrazepam and flurazepam, are less toxic in overdose and are relatively effective in treating insomnia. Chloral hydrate and its derivates are useful alternative drugs for short-term use. Measures to improve sleep without drugs deserve greater emphasis than they have had in the past.     

The stimulant effect of modafinil on wakefulness is not associated with an increase in anxiety in mice

Modafinil is a new drug used in the treatment of narcolepsy. Its administration in mice induced a dose-dependent increase in locomotor activity. The effects of modafinil were compared with those of dexamphetamine on three tests that assessed the anxiety level (drugs were used at doses which induced a roughly similar stimulation of locomotor activity). Dexamphetamine increased the latency of exploration of a white compartment, increased thigmotaxis in an open-field and decreased the time spent in the open arms of an elevated plus-maze. None of these responses was significantly modified by modafinil. We conclude that modafinil does not share the anxiogenic effects of dexamphetamine.     

Stimulant drugs and vigilance performance: a review

The literature on the effects of some stimulant drugs (amphetamine, methylphenidate, caffeine, and nicotine) on vigilance performance is reviewed. Improvement of overall level of performance (both accuracy and speed) after the intake of amphetamine, caffeine, and nicotine has often been reported, and the decrement in performance with time has been shown to be prevented especially with amphetamine and nicotine. Effects on false alarms are negligible. In studies where a test battery was employed, vigilance tasks appeared to be the most sensitive performance tests in detecting the effects of stimulants; however, different vigilance tasks may measure different aspects of mental functions. There is no support for earlier conclusions that improvements are noticed only in fatigued subjects in protracted sessions. Evidence from several studies does not support the hypothesis that improvements are only a recovery of withdrawal-induced impairment. Because positive effects have been obtained with drugs possessing different mechanisms of action, there is as yet no clear support for a noradrenergic, dopaminergic, or cholinergic theory of sustained attention. Simple neurotransmitter theories of attention and information processing may be untenable.     

Pharmacogenetics of anti-cancer drugs

Toxic side-effects of cytotoxic drugs is a stumbling-block of chemotherapy due to the fact that their therapeutic index is narrow. New approaches are necessary to individualize the treatments. Pharmacogenetic analysis is facilitated by easy access to the patient genome via simple blood samples, by the large number of known genes of interest coding for drugs targets or metabolism enzymes and by the fact that their polymorphism (SNP) is often known. Presently more focused on the prevention of toxic side-effects, pharmacogenetics already provides a good deal of confirmed data for clinical applications, such as the detection of dihydropyrimidine dehydrogenase deficiency by sequencing, or UGT1A1 7/7 genotype detection in Gilbert's syndrome for the prevention of 5-FU and irinotecan-induced severe toxicities. It must be emphasized that a SNP which is deleterious for enzyme activity is rarely a contraindication for the drug, provided that some precautions are taken and appropriate therapeutic advice is given by experts.     

Illicit drugs, medications and traffic accidents

The European Union (EU) has 25 member-states and 455 million inhabitants. Statistics on traffic accidents in the EU show that more than 45,000 people are killed annually, including 5200 in France. At the same time, nearly two million persons in the EU require medical treatment for traffic-accident-related injuries, including 109,000 in France. In addition, traffic accidents are the major cause of death of those individuals aged 15 to 24 years. One third of the EU inhabitants will be hospitalized during their life due to a traffic accident with a cost over 160 billion euro (2-3% of the Gross Domestic Product). An important contributing factor to crashes is the use of alcohol and/or illicit drugs or medication when driving, as they exert negative effects on cognition and psychomotor functions. For illicit drugs, abuse of cannabis with or without alcohol is a major concern for the EU. In fact, three million Europeans use cannabis daily and 80% of them drive after use. A number of French studies since 1999 have underlined the high prevalence of cannabis found in the blood of injured or killed drivers. From medical or judicial observations, it is clear that cannabis use increases the risk of traffic accidents. Many groups outside Europe have also shown the association between drug abuse and crashes. The number of casualties related to certain medicines, especially benzodiazepines remains at a high level, particularly in the elderly. In many countries the prevalence of medicinal drugs associated with car accidents is higher than with cannabis. Annex III of the European Union Council Directive of July the 29th 1991 in fact states that a driving license should not be issued to or renewed for applicants or drivers who are dependent on psychotropic substances or use them regularly. Recently, France has categorized the medicinal drugs available in the country by using three pictograms: level one yellow, "be careful"; level two orange, "be very careful"; level three red, "don't drive". It is an important campaign that increases awareness among the public and the medical professionals about the potential dangerous effects of medicinal drugs when driving. The EU objective of reducing the number of fatalities to 25,000 by 2010 will require strengthening measures against the use of alcohol, illicit and medicinal drugs by not well-informed drivers. It is not only a really great challenge, but also a significant investment towards improving public health in France as well as in Europe.     

Affective disorders and biological rhythms

Disruptions of circadian rhythms are described in affective disorders, including unipolar and bipolar disorder, but also seasonal affective disorder. Sleep-wake and hormone circadian rhythms are among the most quoted examples. Depression could be conceptualized as a desynchronization between the endogenous circadian pacemaker and the exogenous stimuli, such as sunlight and social rhythms. Accordingly, Clock genes have been studied and the literature suggests that variants in these genes confer a higher risk of relapse, more sleep disturbances associated with depression, as well as incomplete treatment response. Most of therapeutic interventions in depression have an impact on biological rhythms. Some of them exclusively act via a biological pathway, such as sleep deprivation or light therapy. Some psychosocial interventions are specifically focusing on social rhythms, particularly in bipolar disorder, in which the promotion of stabilization is emphasized. Finally, all antidepressant medications could improve biological rhythms, but some new agents are now totally focusing this novel approach for the treatment of depression.     

Pharmacological therapy of Cushing's syndrome: drugs and indications

OBJECTIVE: To review the main pharmacological properties and clinical applications of the drugs used in the medical therapy of Cushing's syndrome. DATA SOURCES: Search for articles were performed in the following dababases: MEDLINE, EMBASE, Cochrane Database of systematic Reviews and The Cochrane Central Register of Controlled Trials (CENTRAL). Search terms included Cushing's syndrome and drug therapy. DATA SYNTHESIS: Available data suggest that neuromodulatory compounds affect corticotropin (ACTH) or ACTH-releasing hormone (CRH) synthesis and release. They include serotonin antagonists, dopaminergic agonists, valproic acid, reserpine, somatostatin analogs and thiazolidinediones. These agents have been effective in a limited number of patients with ACTH-dependent Cushing's syndrome. Inhibitors of steroidogenesis reduce cortisol production by blocking one (metyrapone, trilostane) or several (aminoglutethimide, ketoconazole, fluconazole, etomidate) enzymes involved in steroid biosynthesis. Mitotane is a steroidogenesis inhibitor with adrenolitic properties. Mifepriston'e blocks glucocorticoid receptor activation without modifying cortisol synthesis. CONCLUSION: Agents that inhibit steroidogenesis are useful in all forms of Cushing's syndrome and are effective in about 70% of patients. Main indications for drug therapy include preparation for surgery, persistence or recurrence after surgery, while awaiting for the effect of radiation therapy, occult ectopic ACTH syndrome, severe hypercortisolism and malignancy related hypercortisolism.     

Medical treatment for neurocysticercosis: drugs, indications and perspectives

Neurocysticercosis is one of the most frequent parasitic diseases affecting the central nervous system. The introduction of anticysticidal therapy in the early 80's and the concomitant improvement of the radiological techniques have lead to apparently significant progress in patient prognosis. However, due to the specificity of the disease, a great debate has been generated on the real usefulness of cysticidal drugs. This article revises and discusses the pharmacological aspects of cysticidal treatment and summarizes current indications for the different types of the disease.     

Legal implications of preparing and dispensing approved drugs for unlabeled indications

The legal issues surrounding the potential liability of a pharmacist for dispensing or preparing drugs under conditions not contained in the FDA-approved labeling of a product are examined. Although the specific issue of liability of a pharmacist for preparing a drug in a nonapproved manner or dispensing a drug for a nonapproved use has not been adjudicated, based on evolving legal principles it appears that the pharmacist under certain circumstances may be held responsible for the drugs so prepared or dispensed. Preparation of a drug which is adulterated under the federal Food, Drug and Cosmetic Act appears to be negligent, although its precise effect will be dependent upon state law. Liability for dispensing for nonapproved uses will be minimized if the pharmacist, in the exercise of sound professional judgment, concludes that the use is rational, safe, and reasonable.     

Lipid-lowering drugs. An overview of indications and optimum therapeutic use

Drug treatment of patients with hyperlipoproteinaemia is indicated to reduce the risk of atherosclerosis in patients with increased concentrations of atherogenic lipoproteins, and to lower the plasma concentrations of triglyceride-rich lipoproteins in patients with severe hypertriglyceridaemia who are at risk of abdominal pain and pancreatitis. Such therapy should be initiated only after satisfactory exclusion of secondary causes of hyperlipoproteinaemia, and should be regarded as an adjunct to rather than a substitute for appropriate dietary therapy. Drug therapy should be strongly considered in those patients with concentrations of atherogenic lipoproteins which exceed the 90th to 95th percentile for age. In patients with increased plasma concentrations of low density lipoproteins (LDL), agents which enhance the rate of LDL catabolism (cholestyramine and colestipol) or reduce the rate of LDL synthesis [e.g. nicotinic acid (niacin)] are the 'drugs of choice'. For those patients with concurrent hypertriglyceridaemia, nicotinic acid is the preferred initial drug, and in both patient groups combined drug therapy is often necessary to attain optimal reductions in LDL cholesterol concentrations. Clofibrate remains the 'drug of choice' for the rare patient with type III hyperlipoproteinaemia, whereas the newer agent gemfibrozil should be used in patients with plasma triglyceride concentrations above 1000 mg/dl who are at increased risk of abdominal pain and pancreatitis. Although currently limited to investigational use, mevinolin and related compounds, which are specific inhibitors of the rate-limiting enzyme in cholesterol biosynthesis (HMG Co-A reductase), offer considerable promise in the therapy of patients with primary hypercholesterolaemia due to elevated levels of LDL cholesterol.