Safety of higher doses of melatonin in adults: A systematic review and meta-analysis.

Melatonin is commonly used for sleep and jetlag at low doses. However, there is less documentation on the safety of higher doses, which are being increasingly used for a wide variety of conditions, including more recently COVID-19 prevention and treatment. The aim of this review was to investigate the safety of higher doses of melatonin in adults. Medline, Scopus, Embase and PsycINFO databases from inception until December 2019 with convenience searches until October 2020. Randomised controlled trials investigating high-dose melatonin (≥10 mg) in human adults over 30 years of age were included. Two investigators independently abstracted articles using PRISMA guidelines. Risk of bias was assessed by a committee of three investigators. 79 studies were identified with a total of 3861 participants. Studies included a large range of medical conditions. The meta-analysis was pooled data using a random effects model. The outcomes examined were the number of adverse events (AEs), serious adverse events (SAEs) and withdrawals due to AEs. A total of 29 studies (37%) made no mention of the presence or absence of AEs. Overall, only four studies met the pre-specified low risk of bias criteria for meta-analysis. In that small subset, melatonin did not cause a detectable increase in SAEs (Rate Ratio = 0.88 [0.52, 1.50], p = .64) or withdrawals due to AEs (0.93 [0.24, 3.56], p = .92), but did appear to increase the risk of AEs such as drowsiness, headache and dizziness (1.40 [1.15, 1.69], p < .001). Overall, there has been limited AE reporting from high-dose melatonin studies. Based on this limited evidence, melatonin appears to have a good safety profile. Better safety reporting in future long-term trials is needed to confirm this as our confidence limits were very wide due to the paucity of suitable data.

The efficacy of combined bright light and melatonin therapies on sleep and circadian outcomes: A systematic review.

The aim of this systematic review was to investigate the effects of combined melatonin and bright light therapies on improved sleep and circadian outcomes. We conducted a systematic review that resulted in a total of eight papers meeting criteria. Four papers investigated the effectiveness of combined therapy in inducing a circadian phase shift on healthy participants. Combined therapy outperformed single light and melatonin therapies in phase advancing, but not in delaying, dim light melatonin onset (DLMO). The other four papers investigated the effect of combined therapy on sleep outcomes. Two of them were performed in elderly populations suffering from cognitive decline and two in delayed sleep-wake phase disorder (DSWPD) patients. While combined therapy was more beneficial than single therapy in elderly populations it did not show any benefit in DSWPD patients. The reported adverse effects of melatonin in elderly populations must be carefully considered. Future studies should investigate the separate and combined effect of melatonin and bright light on sleep and circadian outcomes in different target populations.

Feasibility of 3-month melatonin supplementation for brain oxidative stress and sleep in mild cognitive impairment: protocol for a randomised, placebo-controlled study.

INTRODUCTION: Melatonin has multiple proposed therapeutic benefits including antioxidant properties, synchronisation of the circadian system and lowering of blood pressure. In this protocol, we outline a randomised controlled trial to assess the feasibility, acceptability and tolerability of higher dose (25 mg) melatonin to target brain oxidative stress and sleep disturbance in older adults with mild cognitive impairment (MCI). METHODS AND ANALYSIS: The study design is a randomised double-blind, placebo-controlled, parallel group trial. Forty individuals with MCI will be recruited from the Healthy Brain Ageing Clinic, University of Sydney and from the community, and randomised to receive either 25 mg oral melatonin or placebo nightly for 12 weeks. The primary outcomes are feasibility of recruitment, acceptability of intervention and adherence to trial medication at 12 weeks. Secondary outcomes will include the effect of melatonin on brain oxidative stress as measured by magnetic resonance spectroscopy, blood pressure, blood biomarkers, mood, cognition and sleep. Outcomes will be collected at 6 and 12 weeks. The results of this feasibility trial will inform a future conclusive randomised controlled trial to specifically test the efficacy of melatonin on modifiable risk factors of dementia, as well as cognition and brain function. This will be the first trial to investigate the effect of melatonin in the population with MCI in this way, with the future aim of using this approach to reduce progression to dementia. ETHICS AND DISSEMINATION: This protocol has been approved by the Sydney Local Health District Ethics Committee (X18-0077). This randomised controlled trial will be conducted in compliance with the protocol published in the registry, the International Conference for Harmonisation on Good Clinical Practice and all other applicable regulatory requirements. The findings of the trial will be disseminated via conferences, publications and media, as applicable. Participants will be informed of results of the study at the conclusion of the trial. Eligible authors will include investigators who are involved in the conception and design of the study, the conduct of the trial, the analysis of the results, and reporting and presentation of study findings. TRIAL REGISTRATION NUMBER: Australian and New Zealand Clinical Trials Registry (ANZCTRN 12619000876190). PROTOCOL VERSION: V.8 15 October 2020.

Cannabinoid therapies in the management of sleep disorders: A systematic review of preclinical and clinical studies.

Cannabinoids, including the two main phytocannabinoids Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), are being increasingly utilised as pharmacological interventions for sleep disorders. THC and CBD are known to interact with the endocannabinoid and other neurochemical systems to influence anxiety, mood, autonomic function, and circadian sleep/wake cycle. However, their therapeutic efficacy and safety as treatments for sleep disorders are unclear. The current systematic review assessed the available evidence base using PubMed, Scopus, Web of Science, Embase, CINAHL and PsycInfo databases. A total of 14 preclinical studies and 12 clinical studies met inclusion criteria. Results indicated that there is insufficient evidence to support routine clinical use of cannabinoid therapies for the treatment of any sleep disorder given the lack of published research and the moderate-to-high risk of bias identified within the majority of preclinical and clinical studies completed to-date. Promising preliminary evidence provides the rationale for future randomised controlled trials of cannabinoid therapies in individuals with sleep apnea, insomnia, post-traumatic stress disorder-related nightmares, restless legs syndrome, rapid eye movement sleep behaviour disorder, and narcolepsy. There is a clear need for further investigations on the safety and efficacy of cannabinoid therapies for treating sleep disorders using larger, rigorously controlled, longer-term trials.

The efficacy of biofeedback for the treatment of insomnia: a critical review.

BACKGROUND: The popularity of biofeedback as a non-pharmacological treatment option for insomnia has increased in recent times despite inconsistent empirical evidence for its therapeutic efficacy. OBJECTIVE: The purpose of the current review was to systematically assess the efficacy of using biofeedback to treat insomnia. METHODS AND RESULTS: A search of electronic databases (PubMED, MEDLINE, OvidSP, Ovid EMBASE, PsychInfo, The Cochrane Library including Cochrane Reviews), clinical trials databases and registries (Clinical Trials Database [US], Australian New Zealand Clinical Trials Registry [ANZCTR]) and online journal (eg, SLEEP, Sleep Medicine) identified 92 studies. Of these, 50 publications were descriptive or review papers about use of biofeedback for the treatment of insomnia, while an additional 37 did not meet the detailed inclusion criteria (ie not original research, participants do not meet the diagnostic criteria for insomnia). Six full-text articles met inclusion criteria and were included in this review. Methodological flaws including poor study design (small sample size, lack of control group) limit the validity of the body of work in this field to date and fail adequately to account for other unspecified factors likely to drive the observed changes, such as care and attention of those administering the treatment, as well as the expectations and motivations of the patient. CONCLUSION: There is an urgent need for future studies to clarify the role of unspecific placebo effects when reporting biofeedback effects for the treatment of insomnia.

Chronotherapy for hypertension in obstructive sleep apnoea (CHOSA): a randomised, double-blind, placebo-controlled crossover trial.

BACKGROUND: Obstructive sleep apnoea (OSA) is an important cause of secondary hypertension. Nocturnal hypertension is particularly prevalent in OSA and is a strong predictor of cardiovascular mortality. Studies in patients with essential hypertension have suggested that nocturnal administration of antihypertensives improves nocturnal blood pressure (BP) without elevating daytime BP. We evaluated the efficacy of this technique in patients with OSA with stage I/II hypertension, both before and after the addition of CPAP. METHODS: In this double-blind randomised placebo-controlled crossover trial, patients with moderate-to-severe OSA and hypertension received 6 weeks each of evening or morning perindopril with opposing time-matched placebo. CPAP therapy was subsequently added for 8 weeks in addition to either morning or evening perindopril. The primary outcome was sleep systolic BP (SBP) using 24-hour BP monitoring, analysed using linear mixed models. RESULTS: Between March 2011 and January 2015, 85 patients were randomised, 79 completed both dosing times, 78 completed the CPAP phase. Sleep SBP reduced significantly from baseline with both evening (-6.9 mm Hg) and morning (-8.0 mm Hg) dosing, but there was no difference between dosing times (difference: 1.1 mm Hg, 95% CI -0.3 to 2.5). However, wake SBP reduced more with morning (-9.8 mm Hg) than evening (-8.0 mm Hg) dosing (difference: 1.8 mm Hg, 95% CI 1.1 to 2.5). Addition of CPAP to either evening or morning dosing further reduced sleep SBP, but by a similar amount (evening: -3.2 mm Hg, 95% CI -5.1 to -1.3; morning: -3.3 mm Hg, 95% CI -5.2 to 1.5). CONCLUSIONS: Our findings support combining OSA treatment with morning administration of antihypertensives. Unlike in essential hypertension, our results do not support evening administration of antihypertensives, at least with perindopril. Further research is required before this strategy can be widely adopted into hypertension guidelines and clinical practice. TRIAL REGISTRATION NUMBER: ACTRN12611000216910, Results.

Modafinil improves daytime sleepiness in patients with mild to moderate obstructive sleep apnoea not using standard treatments: a randomised placebo-controlled crossover trial.

INTRODUCTION: Patients with mild to moderate obstructive sleep apnoea (OSA) commonly suffer excessive daytime sleepiness. Continuous positive airway pressure (CPAP) has limited effectiveness in reducing sleepiness in milder OSA. Modafinil is a wake-promoting drug licensed to treat residual sleepiness in CPAP-treated OSA. We hypothesised that modafinil may effectively treat sleepiness in untreated mild to moderate OSA. METHODS: Untreated sleepy men with mild to moderate OSA (age 18-70, apnoea-hypopnoea index (AHI) 5-30/h, Epworth Sleepiness Scale (ESS) ≥10) were randomised to receive 200 mg modafinil or matching placebo daily for 2 weeks before crossing over to the alternative treatment after a minimum 2-week washout. Mixed model analysis of variance was used to compare the changes on modafinil to placebo while classifying all randomised patients as random factors. RESULTS: 32 patients were randomised (mean (SD) AHI 13 (6.4)/h, age 47 (10.7) years, ESS 13.6 (3.3), body mass index 28.2 (3.6) kg/m(2)), 29 of whom (91%) completed the trial. The primary outcome (ESS) improved more on modafinil than placebo (3.6 points, 95% CI 1.3 to 5.8, p=0.003) and the secondary outcome (40-min driving simulator performance) also improved more on modafinil than placebo (steering deviation 4.7 cm, 95% CI 0.8 to 8.5, p=0.018). Psychomotor Vigilance Task reciprocal reaction time improved significantly over placebo (0.15 (1/ms), 95% CI 0.03 to 0.27, p=0.016). Improvements on the Functional Outcomes of Sleep Questionnaire were not significant (5.3 points over placebo, 95% CI -1 to 11.6, p=0.093). CONCLUSIONS: Modafinil significantly improved subjective sleepiness in patients with untreated mild to moderate OSA. The size of this effect is clinically relevant at 3-4 ESS points of improvement compared with only 1-2 points in CPAP clinical trials. Driving simulator performance and reaction time also improved on modafinil. CLINICAL TRIAL REGISTRATION: ACTRN#12608000128392.

Treatments for somnambulism in adults: assessing the evidence.

Somnambulism, or sleepwalking, is a parasomnia of non-rapid eye movement (NREM) sleep where movement behaviours usually confined to wakefulness are displayed during sleep. Generally, if sleepwalking is causing distress or danger in spite of safety measures, medical or psychological treatment is indicated. Clinicians will need to assess the evidence for treatment options. MEDLINE, EMBASE, PsycINFO and the Ovid Evidence-Based Medicine Reviews (EBM) multifile databases were searched. No properly powered rigorous controlled trials were found for treatment of sleepwalking in adults. Seven reports described small trials with some kind of control arm, or retrospective case series which included 30 or more patients. With no high quality evidence to underpin recommendations for treatments of somnambulism, full discussion with patients is advised. Adequately powered, well-designed clinical trials are now needed, and multi-centre collaborations may be required to obtain the sample sizes required.

Brain function in obstructive sleep apnea: results from the Brain Resource International Database.

Obstructive sleep apnea (OSA) is expected to impair vigilance and executive functioning, owing to the sensitivity of the prefrontal cortex to the effects of sleep fragmentation and intermittent hypoxia. Studies examining the pattern of cognitive dysfunction show variable results, with the heterogeneity in part due to small sample sizes in current studies and little consistency of the tests used. We examined a group of fifty subjects from the Brain Resource International Database (BRID), predicted to have OSA on the basis of the Multivariable Apnea Prediction Index, and compared them with 200 matched controls. On electrophysiological tests, the OSA group showed reduced eyes closed alpha power, increased auditory oddball N100 and P200 amplitude, but reduced N200 and P300 amplitude. The latency to P300 was not significantly different between groups, but latencies to N200 and P200 were prolonged in the OSA group. Performance testing of the executive function found that verbal interference and the switching of attention were impaired in the OSA group. We have demonstrated that a diagnostic algorithm based on apnea symptoms and demographic factors can be used to select a group with likely OSA manifesting deficits in information processing and executive function.