Modafinil for excessive sleepiness associated with shift-work sleep disorder

A clinical approach to circadian rhythm sleep disorders

Circadian rhythm sleep disorders are characterized by complaints of insomnia and excessive sleepiness that are primarily due to alterations in the internal circadian timing system or a misalignment between the timing of sleep and the 24-h social and physical environment. In addition to physiological and environmental factors, maladaptive behaviors often play an important role in the development of many of the circadian rhythm sleep disorders. This review will focus on the clinical approach to the diagnosis and management of the various circadian rhythm sleep disorders, including delayed sleep phase disorder, advanced sleep phase disorder, non-entrained type, irregular sleep-wake rhythm, shift work sleep disorder and jet lag disorder. Diagnostic tools such as sleep diaries and wrist activity monitoring are often useful in confirming the diagnosis. Because behavioral and environmental factors often are involved in the development of these conditions, a multimodal approach is usually necessary. Interventions include sleep hygiene education, timed exposure to bright light as well as avoidance of bright light at the wrong time of the day and pharmacologic approaches, such as melatonin. However, it should be noted that the use of melatonin is not an FDA-approved indication for the treatment of circadian rhythm sleep disorders.

An open study of modafinil for the treatment of daytime somnolence and fatigue in primary biliary cirrhosis

BACKGROUND

Fatigue is a debilitating symptom which frequently impairs the quality of life of patients with primary biliary cirrhosis (PBC). Although the mechanisms underpinning fatigue in PBC remain unclear, there is an emerging consensus that CNS mechanisms play a key role. It has recently been shown that there is a strong association between abnormalities in sleep regulation, in particular excessive daytime somnolence, and fatigue severity in PBC. The CNS-acting drug modafinil has an established role in the treatment of excessive daytime somnolence in non-liver disease states.

AIM

To explore, in an open label study, the responses of PBC patients suffering from significant daytime somnolence and associated fatigue to modafinil therapy.

METHODS

All patients in the series (n = 21) underwent daytime somnolence assessment using the Epworth Sleepiness Scale and PBC symptom assessment using the PBC-40, a multi-domain, disease specific, psychometrically robust quality of life measure. Modafinil was started at a dose of 100 mg/day and was titrated according to tolerability and response. Patients underwent repeat Epworth Sleepiness Scale and PBC-40 assessment after 2 months of treatment.

RESULTS

Significant improvement was seen in Epworth Sleepiness Scale scores with modafinil therapy [15 +/- 3 vs. 8 +/- 6, P < 0.0005 (intention-to-treat analysis)]. An equally significant improvement in fatigue severity was also seen [PBC-40 fatigue domain score (46 +/- 6 vs. 34 +/- 12, P < 0.0001) (intention-to-treat analysis)].

CONCLUSIONS

Open label modafinil therapy was associated, where tolerated by patients, with improvement in excessive daytime somnolence and associated fatigue in PBC. Further study in placebo-controlled trials is warranted.

Treatment of attention deficits in neurological disorders

PURPOSE OF REVIEW

Recent work has revealed the impact of deficits of attention on patients with neurological disorders. Here we discuss therapeutic interventions that have been used across a range of conditions, highlighting common themes both in the nature of the attention deficits and the strategies employed to treat them.

RECENT FINDINGS

Cholinesterase inhibitors improve attention, as well as memory, in several conditions including cortical Lewy body disease, Parkinson's disease dementia, traumatic brain injury and Alzheimer's disease. Recent studies suggest that cholinergic stimulation may boost attention further if more specific nicotinic cholinergic agonists are used, or if cholinesterase inhibitors are combined with other agents. Monoaminergic drugs have been shown to improve attention in traumatic brain injury, attention-deficit hyperactivity disorder and hemispatial neglect following right-hemisphere stroke. New compounds targeting other neurotransmitter systems are currently being tested, while several types of behavioural intervention have shown promise, particularly in stroke patients.

SUMMARY

Pharmacological and behavioural interventions can improve attention in neurological patients. In the future, optimum therapy may depend on careful delineation of the components of attention that are impaired as well as assessment of the potential for surviving brain regions to compensate for attention deficits.

Circadian rhythm sleep disorders

Humans exhibit endogenous circadian rhythms that are regulated by the master circadian clock of the body, the suprachiasmatic nucleus. These endogenous circadian rhythms are aligned to the outside world by social and environmental cues. Circadian rhythm sleep disorders (CRSD) occur when there is an alteration of the internal timing mechanism or a misalignment between sleep and the 24-h social and physical environment. CRSD are often underrecognized yet should be considered in the differential of patients presenting with symptoms of insomnia and/or hypersomnia. Because behavioral and environmental factors often are involved in the development and maintenance of these conditions, a multimodal treatment approach of behavioral and/or pharmacologic approaches is usually required to synchronize a patient's circadian rhythm to the 24-h environment, consolidate sleep, and improve alertness. Rapid advances in our understanding of the physiologic, cellular, and molecular basis of circadian rhythm and sleep regulation will likely lead to improved diagnostic tools and treatments for CRSD.

Modafinil for excessive sleepiness associated with chronic shift work sleep disorder: effects on patient functioning and health-related quality of life

OBJECTIVE

We evaluated the effects of modafinil, a wake-promoting agent, on patient functioning, health-related quality of life, and nighttime and daytime sleep in patients with excessive sleepiness associated with shift work sleep disorder (SWSD).

METHOD

A 12-week, randomized, double-blind, placebo-controlled study was performed at 31 centers in the United States between February 2001 and March 2002. Adults (N = 278) with excessive sleepiness associated with chronic SWSD (International Classification of Sleep Disorders criteria) were randomly assigned to receive modafinil 200 or 300 mg or placebo, 30 to 60 minutes before each night shift. Effects on patient functioning and quality of life were assessed using the Functional Outcomes of Sleep Questionnaire (FOSQ) and the 36-item Short Form Health Survey (SF-36), respectively. Daily patient diaries were used as a sleep log.

RESULTS

Modafinil 300 mg significantly improved mean FOSQ total score relative to placebo (2.3-point increase from baseline vs. 1.6 for placebo; p < .05). Both doses of modafinil significantly improved mean SF-36 mental component scores relative to placebo (mean changes from baseline of 3.2, 3.7, and 0.7 points in the modafinil 300-mg, modafinil 200-mg, and placebo groups, respectively; p < .05 for each comparison vs. placebo). Modafinil did not adversely affect sleep when sleep was desired or caffeine use. Modafinil was well tolerated. Headache (21.5%) and nausea (12.4%) were the most common adverse events in modafinil-treated patients. Differences between modafinil and placebo for vital sign measurements, physical examination findings, or electrocardiography results were not clinically meaningful.

CONCLUSIONS

Modafinil significantly improves functioning and quality of life in patients with SWSD. Modafinil is an effective treatment for excessive sleepiness associated with SWSD.

Circadian rhythm sleep disorders and phototherapy

Circadian rhythm sleep disorders are characterized by a desynchronization between the timing of the intrinsic circadian clock and the extrinsic light-dark and social/activity cycles resulting in symptoms of excessive sleepiness and insomnia. This article explores the six recognized circadian rhythm sleep disorders: delayed sleep phase syndrome, advanced sleep phase syndrome, non-24-hour sleep-wake syndrome, irregular sleep-wake pattern, shift work sleep syndrome, and time zone change syndrome. Additionally discussed are the therapeutic roles of synchronizing agents, such as light and melatonin.

Excessive daytime sleepiness: considerations for the psychiatrist

Excessive daytime sleepiness or pathologic sleepiness is a complaint found in patients who experience somnolence at unwanted times and adversely affects their daytime function. Although psychiatric illness, chronic medical illness, or medication side effects may be causes for fatigue, insufficient sleep is the most common cause of excessive daytime sleepiness in the general population. When an individual complains of frank sleepiness, in addition to insufficient sleep, important considerations in these patients are disturbances in the normal homeostatic mechanisms that govern sleep and wakefulness. This article summarizes the clinical presentation, the differential diagnosis, commonly used diagnostic tools, and treatment options for patients complaining of excessive daytime sleepiness.

Altered sleep/wake patterns and mental performance

Altered sleep/wake patterns involve, by definition, displaced sleep. The present review concludes that mental performance is strongly influenced by many forms of displaced sleep. Being exposed to the circadian low (during work/activity), extended time awake or reduced duration of sleep will impair performance. The effect is most pronounced in the laboratory setting, however, even if a number of studies have shown effects of for example night work on neuropsychological tests, and simulated work. In real shift work situations performance changes have been less pronounced. No studies have evaluated the effects on production, but accidents and serious mistakes have been clearly established in road transport and there seems to be clear effects also in health care. The effects are similar in connection with flights across several time zones (jet lag) but less data are available. It is suggested that there is a need for establishing the significance of impaired performance due to work hours in white collar and service work. Also the notion of individual differences in performance impairment is an important issue.

Adenosinergic mechanisms contribute to individual differences in sleep deprivation-induced changes in neurobehavioral function and brain rhythmic activity

Large individual differences characterize the changes induced by sleep deprivation on neurobehavioral functions and rhythmic brain activity. To investigate adenosinergic mechanisms in these differences, we studied the effects of prolonged waking and the adenosine receptor antagonist caffeine on sustained vigilant attention and regional electroencephalogram (EEG) power in the ranges of theta activity (6.25-8.25 Hz) in waking and the slow oscillation (<1 Hz) in sleep. Activity in these frequencies is functionally related to sleep deprivation. In 12 subjectively caffeine-sensitive and 10 -insensitive young men, psychomotor vigilance task (PVT) performance and EEG were assessed at 3 h intervals before, during, and after one night without sleep. After 11 and 23 h waking, subjects received 200 mg caffeine and placebo in double-blind, cross-over manner. In the placebo condition, sleep deprivation impaired PVT speed more in caffeine-sensitive than in caffeine-insensitive men. This difference was counteracted by caffeine. Theta power in waking increased more in a frontal EEG derivation than in a posterior derivation. Caffeine attenuated this power gradient in caffeine sensitive subjects. Sleep loss also differently affected the power distribution <1 Hz in non-rapid eye movement sleep between caffeine sensitive and insensitive subjects. Also, this difference was mirrored by the action of caffeine. The effects of sleep deprivation and caffeine on sustained attention and regional EEG power in waking and sleep were inversely related. These findings suggest that adenosinergic mechanisms contribute to individual differences in waking-induced impairment of neurobehavioral performance and functional aspects of EEG topography associated with sleep deprivation.

Modafinil for atypical depression: effects of open-label and double-blind discontinuation treatment

Atypical depression, with features of hypersomnia, hyperphagia, anergia, and rejection sensitivity, is a common presentation of major depressive disorder. There are few available effective therapies for this disorder. We test modafinil, a novel wake-promoting agent, as monotherapy for atypical depression in a double-blind, placebo-controlled, relapse prevention trial after open-label treatment. We found that modafinil significantly improved atypical depression symptoms during 12 weeks of open-label treatment (mean +/- SD Hamilton Depression Scale (29-item version) score changed from 34 +/- 8.2 at baseline to 9.7 +/- 9.3, P < 0.0001), and that benefits were maintained alike in both the continuation and placebo arms during the double-blind treatment phase (P = 0.92). Modafinil was well tolerated and the drug was associated with significant weight loss compared with placebo (P = 0.01).

The neural bases of momentary lapses in attention

Momentary lapses in attention frequently impair goal-directed behavior, sometimes with serious consequences. Nevertheless, we lack an integrated view of the brain mechanisms underlying such lapses. By investigating trial-by-trial relationships between brain activity and response time in humans, we determined that attentional lapses begin with reduced prestimulus activity in anterior cingulate and right prefrontal regions involved in controlling attention. Less efficient stimulus processing during attentional lapses was also characterized by less deactivation of a 'default-mode' network, reduced stimulus-evoked sensory activity, and increased activity in widespread regions of frontal and parietal cortex. Finally, consistent with a mechanism for recovering from attentional lapses, increased stimulus-evoked activity in the right inferior frontal gyrus and the right temporal-parietal junction predicted better performance on the next trial. Our findings provide a new, system-wide understanding of the patterns of brain activity that are associated with brief attentional lapses, which informs both theoretical and clinical models of goal-directed behavior.

Modafinil [2-[(Diphenylmethyl)sulfinyl]acetamide] and Circadian Rhythms in Syrian Hamsters: Assessment of the Chronobiotic Potential of a Novel Alerting Compound

In Syrian hamsters, behavioral procedures for inducing arousal (e.g., running in a novel wheel or gentle handling) can shift circadian rhythms when applied during the usual sleep period ("subjective day") and can attenuate phase shifts to light during the active period ("subjective night"). This raises the possibility that drugs that affect behavioral state may have "chronobiotic" potential. We characterized the effects of modafinil (2-[(diphenylmethyl)sulfinyl]acetamide), an atypical alerting compound, on circadian rhythms in male Syrian hamsters. Electroencephalogram recordings and video observations confirmed that modafinil dose dependently increases wakefulness at the expense of slow-wave and paradoxical sleep with no increase in locomotor activity per unit of time awake. Despite inducing arousal, modafinil at these doses (150 or 300 mg/kg), administered in the subjective day or early or late in the subjective night, did not perturb circadian phase. Modafinil (300 mg/kg) also had no effect on phase shifts to light exposure either early or late in the night and did not alter the size of phase shifts induced by running in a novel wheel for 3 h during the mid-day. Modafinil (300 mg/kg) did, however, decrease by approximately 50% the amount of novel wheel-stimulated running, moving leftward the dose-response relation between wheel revolutions and shift magnitude. These results indicate that, in Syrian hamsters, modafinil alone has no significant chronobiotic efficacy. Nevertheless, this agent may increase the sensitivity of the circadian pacemaker to nonphotic stimuli and may thus have some potential as a tool for promoting clock resetting in combination with behavioral strategies.

Shift Work Sleep Disorder

More than 6 million Americans work night shifts on a regular or rotating basis. The negative consequences of shift work have been established, and recent evidence suggests that patients with shift work sleep disorder (SWSD) are at increased risk of these consequences and co-morbidities. SWSD is a relatively common but under-recognised, and hence undertreated, condition with potentially serious medical, social, economic and quality-of-life consequences. In addition to increased risk of gastrointestinal and cardiovascular disease, patients with SWSD experience clinically significant excessive sleepiness or insomnia associated with work during normal sleep times, which has important safety implications. A number of studies have evaluated countermeasures or interventions in shift workers; proposed treatments include chronobiotic interventions, such as light exposure, melatonin, hypnotic agents, caffeine and CNS stimulants (amphetamine), and the wake-promoting agents modafinil and armodafinil. However, most studies evaluating pharmacological therapies and nonpharmacological interventions simulate night-shift work under conditions that may not accurately reflect real-world activities. Pharmacological and nonpharmacological countermeasures evaluated mostly in simulated laboratory conditions have been shown to improve alertness or sleep in shift workers but have not yet been evaluated in patients with SWSD. To date, three randomised, double-blind clinical studies have evaluated pharmacological therapies in patients with SWSD. These studies showed that modafinil and armodafinil significantly improve the ability to sustain wakefulness during waking activities (e.g. working, driving), overall clinical condition, and sustained attention or memory in patients with SWSD. In conclusion, SWSD is a common condition that remains under-recognised and undertreated. Further research is needed to evaluate different treatment approaches for this condition, to clarify the substantial health and economic consequences of SWSD, and to determine the potential for interventions or treatments to reduce the negative consequences of this condition.

Pharmacodynamic effects on alertness of single doses of armodafinil in healthy subjects during a nocturnal period of acute sleep loss

OBJECTIVE

To assess the pharmacodynamics of armodafinil compared with modafinil and placebo on measures of alertness in healthy volunteers undergoing sleep loss.

RESEARCH DESIGN AND METHODS

In a double-blind, active- and placebo-controlled, parallel-group study, 107 healthy male volunteers (aged 18-40 years) were randomized to receive a single oral dose of armodafinil (100, 150, 200, or 300 mg), modafinil (200 mg), or placebo administered at 19:25 h.

MAIN OUTCOME MEASURES

The primary outcome was the Maintenance of Wakefulness Test (MWT), administered every 2 hours from 22:00-08:00 h. Secondary outcomes included the Psychomotor Vigilance Task (PVT) and the Karolinska Sleepiness Scale. Blood samples for pharmacokinetic analysis were collected hourly. Adverse events were evaluated throughout the 2-day laboratory stay and by telephone on day 9.

RESULTS

All four doses of armodafinil, and the dose of 200 mg modafinil, improved wakefulness as measured by increased MWT latencies (treatment effect, p < 0.0001) and reduced PVT lapses of attention (treatment effect, p < 0.0001). The magnitude and duration of these effects at the later time points appeared to be dose and concentration dependent. Armodafinil at 200 mg resulted in comparable C(max), a later t(max), and higher plasma concentrations 6-14 hours post-drug administration than with 200 mg modafinil. Following armodafinil, longer MWT latencies and fewer PVT lapses 6 to approximately 14 hours post-drug administration were observed compared with modafinil. Armodafinil doses were well tolerated, with the most common adverse events including abdominal pain, nausea, and headache. There were reports of tachycardia/palpitations. Decreased mean sleep efficiency and increased mean blood pressure were also observed.

CONCLUSION

Armodafinil improved alertness at all doses studied. Relative to modafinil 200 mg, armodafinil 200 mg showed a comparable peak plasma concentration with higher concentrations 6-14 hours post-drug, and improved wakefulness and sustained attention for a longer time post-dose. Both drugs were well tolerated; however, further research on the efficacy, safety, and tolerability of armodafinil in patients with disorders of excessive sleepiness (ES) is required.