Orexins are hypothalamic peptides that play an important role in maintaining wakefulness in mammals. Permanent deficit in orexinergic function is a pathophysiological hallmark of rodent, canine and human narcolepsy. Here we report that in rats, dogs and humans, somnolence is induced by pharmacological blockade of both orexin OX(1) and OX(2) receptors. When administered orally during the active period of the circadian cycle, a dual antagonist increased, in rats, electrophysiological indices of both non-REM and, particularly, REM sleep, in contrast to GABA(A) receptor modulators; in dogs, it caused somnolence and increased surrogate markers of REM sleep; and in humans, it caused subjective and objective electrophysiological signs of sleep. No signs of cataplexy were observed, in contrast to the rodent, dog or human narcolepsy syndromes. These results open new perspectives for investigating the role of endogenous orexins in sleep-wake regulation.

Summary:Purpose: This study was designed to assess whether sleep disturbance is more frequent among patients with partial seizures and what impact on quality of life (QoL) sleep disturbance may have on patients with partial seizures.Methods: Questionnaire booklets were mailed to 1,183 patients from four Dutch clinics. Each patient was asked to find two age-and gender-matched controls to complete the same set of questionnaires [Sleep Diagnosis List (SDL), Medical Outcomes Study (MOS)-Sleep Scale, Groningen Sleep Questionnaire, Epworth Sleepiness Scale, and the SF-36 Health Survey]. The prevalence of sleep disturbance, based on the SDL, was compared between those with partial epilepsy and controls. Mean scores on sleep and the SF-36 Physical (PCS) and Mental (MCS) Component Summary scales were compared.Results: Responses from 486 patients and 492 controls were analyzed. Respondents with partial epilepsy had a highly significant, twofold higher prevalence of sleep disturbance compared with controls (38.6 vs. 18.0%; p < 0.0001). Most sleep-disorder subscales showed significant abnormalities in respondents with epilepsy, compared with controls. Mean SF-36 MCS and PCS scores were significantly lower in respondents with epilepsy compared with controls in both the strata with sleep disturbance and without (all p values <0.05). The presence of a sleep disturbance in respondents with epilepsy was associated with the greatest impairment in QoL.Conclusions: Sleep disturbance is more than twice as prevalent in persons with partial epilepsy compared with controls, and most domains of sleep are significantly disturbed. Persons with partial epilepsy have significant QoL impairment, and sleep disturbance further compounds this.

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PF-06372865 has a unique clinical pharmacology profile and a highly predictive translational data package from preclinical species to the clinical setting.

The orexin system regulates sleep and arousal and is targeted by ACT-541468, a new dual orexin receptor antagonist (DORA). Healthy male subjects received a single oral dose of 5-200 mg to assess safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), mass balance, metabolism, and absolute bioavailability utilizing a C-labeled, orally and intravenously (i.v.) administered microtracer. The drug was safe and well tolerated; the PK profile was characterized by quick absorption and elimination, with median time to reach maximum concentration (t ) of 0.8-2.8 h and geometric mean terminal half-life (t ) of 5.9-8.8 h. Clear dose-related effects on the central nervous system were observed at ≥25 mg, indicating a suitable PK-PD profile for a sleep-promoting drug, allowing for rapid onset and duration of action limited to the intended use. This comprehensive first-in-human study created a wealth of data, while saving resources in drug development.