Melatonin as add-on treatment for epilepsy

Melatonin as an add-on treatment for epilepsy: A systematic review and meta-analysis

PURPOSE

Epilepsy, one severe prevalent brain disorder, primarily relies on drug treatment. However, approximately one-third of patients with epilepsy do not achieve effective control with current medications, underscoring the need for more innovative treatment approaches. Notably, melatonin has gained attention for its anti-seizure properties and favourable safety profile. This systematic review aimed to evaluate the efficacy and safety of melatonin as an add-on treatment for epilepsy.

METHODS

We searched for articles published before June 2023 in Web of Science, Cochrane Library, and PubMed. We used RevMan 5.4 software to compute relative risks (RRs) and 95 % confidence intervals (CIs). Key outcomes included total sleep time, wakefulness after sleep onset, sleep latency, seizure frequency, seizure severity, and safety. The quality of randomised controlled studies (RCTs) was assessed using the Cochrane Risk of Bias tool.

RESULTS

Of the 264 publications retrieved, 10 RCTs were included in the meta-analysis. Add-on melatonin treatment improved sleep latency (RR: 0.56; 95 %CI: 0.10-1.02; P = 0.02) and seizure severity (RR: 0.33; 95 %CI: 0.04-0.62; P = 0.03) compared with placebo treatment. Adverse events (increased headache severity in children with a history of migraines, bronchitis, ear infections, agitation, and urinary frequency) were reported in only one trial.

CONCLUSION

This systematic review found that add-on melatonin therapy improved sleep latency and seizure severity in patients with epilepsy. However, several of the included studies did not systematically assess sleep quality, seizures, and safety and lacked long-term follow-up data. Further RCTs with extended follow-up periods are required to definitively determine the efficacy and safety of melatonin.

Pediatric sleep disturbances and treatment with melatonin

Background

There are no guidelines concerning the best approach to improving sleep, but it has been shown that it can benefit the affected children and their entire families. The aim of this review is to analyse the efficacy and safety of melatonin in treating pediatric insomnia and sleep disturbances.

Main body

Sleep disturbances are highly prevalent in children and, without appropriate treatment, can become chronic and last for many years; however, distinguishing sleep disturbances from normal age-related changes can be a challenge for physicians and may delay treatment. Some published studies have shown that melatonin can be safe and effective not only in the case of primary sleep disorders, but also for sleep disorders associated with various neurological conditions. However, there is still uncertainty concerning dosing regimens and a lack of other data. The dose of melatonin should therefore be individualised on the basis of multiple factors, including the severity and type of sleep problem and the associated neurological pathology.

Conclusions

Melatonin can be safe and effective in treating both primary sleep disorders and the sleep disorders associated with various neurological conditions. However, there is a need for further studies aimed at identifying the sleep disordered infants and children who will benefit most from melatonin treatment, and determining appropriate doses based on the severity and type of disorder.

Melatonin in Critically Ill Children

Melatonin, while best known for its chronobiologic functions, has multiple effects that may be relevant in critical illness. It has been used for circadian rhythm maintenance, analgesia, and sedation, and has antihypertensive, anti-inflammatory, antioxidant, antiapoptotic, and antiexcitatory effects. This review examines melatonin physiology in health, the current state of knowledge regarding endogenous melatonin production in pediatric critical illness, and the potential uses of exogenous melatonin in this population, including relevant information from basic sciences and other fields of medicine. Pineal melatonin production and secretion appears to be altered in critical illness, though understanding in pediatric critical illness is in early stages, with only 102 children reported in the current literature. Exogenous melatonin may be used for circadian rhythm disturbances and, within the critically ill population, holds promise for diseases involving oxidant stress. There are no studies of exogenous melatonin administration to critically ill children beyond the neonatal period.

Melatonin as add-on treatment for epilepsy

BACKGROUND

This is an updated version of the original Cochrane review published in Issue 6, 2012.Epilepsy is one of the most common chronic neurological disorders. Despite the plethora of antiepileptic drugs (AEDs) currently available, 30% of people continue having seizures. This group of people requires a more aggressive treatment, since monotherapy, the first choice scheme, fails to control seizures. Nevertheless, polytherapy often results in a number of unwanted effects, including neurological disturbances (somnolence, ataxia, dizziness), psychiatric and behavioural symptoms, and metabolic alteration (osteoporosis, inducement or inhibition of hepatic enzymes, etc.). The need for better tolerated AEDs is even more urgent in this group of people. Reports have suggested an antiepileptic role of melatonin with a good safety profile.

OBJECTIVES

To assess the efficacy and tolerability of melatonin as add-on treatment for epilepsy.

SEARCH METHODS

For the latest update, we searched the Cochrane Epilepsy Group's Specialized Register (12 January 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) via the Cochrane Register of Studies Online (CRSO, 12 January 2016), and MEDLINE (Ovid, 11 January 2016). We searched the bibliographies of any identified study for further references. We handsearched selected journals and conference proceedings. We applied no language restrictions. In addition, we contacted melatonin manufacturers (i.e. Nathura) and original investigators to identify any unpublished studies.

SELECTION CRITERIA

Randomized controlled trials; double, single, or unblinded trials; parallel group or cross-over studies. People with epilepsy regardless of age and gender, including children and adults with disabilities. Administration of melatonin as add-on treatment to any AED(s) compared to add-on placebo or no add-on treatment.

DATA COLLECTION AND ANALYSIS

Review authors independently selected trials for inclusion according to pre-defined criteria, extracted relevant data, and evaluated the methodological quality of trials. We assessed the following outcomes: at least 50% seizure reduction, seizure freedom, adverse events, and quality of life.

MAIN RESULTS

We included six publications, with 125 participants (106 aged under 18 years). Two different comparisons were available: melatonin versus placebo and melatonin 5 mg versus melatonin 10 mg. Despite our primary intention, due to insufficient information on outcomes, we were unable to perform any meta-analyses, but summarized data narratively. Four studies were randomized, double-blind, cross-over, placebo-controlled trials and two were randomized, double-blind, parallel, placebo-controlled trials. Only two studies provided the exact number of seizures during the trial compared to the baseline: none of the participants with seizures during the trial had a change in seizure frequency compared with the baseline. Two studies systematically evaluated adverse effects (worsening of headache was reported in a child with migraine under melatonin treatment). Only one study systematically evaluated quality of life, showing no statistically significant improvement in quality of life in the add-on melatonin group.

AUTHORS' CONCLUSIONS

Included studies were of poor methodological quality, and did not systematically evaluate seizure frequency and adverse events, so that it was impossible to summarize data in a meta-analysis. It is not possible to draw any conclusion about the role of melatonin in reducing seizure frequency or improving quality of life in people with epilepsy.

Which outcomes should we measure in adult epilepsy trials? The views of people with epilepsy and informal carers

OBJECTIVE

So that informed treatment decisions can be made, clinical trials need to evaluate treatments against domains that are important to people with epilepsy (PWE), their carers, and clinicians. Health professionals have identified domains of importance to them via the International League Against Epilepsy's Commission on Outcome Measurement (COME). However, patients and carers have not been systematically asked.

METHODS

Via the membership of the British Epilepsy Association, we recruited and surveyed 352 PWE and 263 of their informal carers. They were presented with 10 outcome domains (including the 5 identified by COME) and asked to rate their importance using a 9-point Likert scale. They were also asked to identify any additional domains of importance.

RESULTS

The patients' mean age was 49years, the median number of years since diagnosis was 20, and 65% had experienced seizures in the prior 12months. Most carers were the spouse or parent. Patients' and carers' mean ratings indicated that their outcome priorities were similar, as were those of patients who had and had not experienced recent seizures. There was consensus among patients that 6 domains were of critical importance. These included the 5 identified by COME (namely, and in order of importance, the effects of the treatment on "Seizure severity", "Seizure frequency", "Quality of life", "Cognitive function", and "Adverse events"), as well as one additional domain ("Independence/need for support"). There was consensus among carers that the 5 COME domains were also critically important. They, however, identified 3 further domains as critically important. These were the effects of the treatment on patient "Depression", "Anxiety", and "Independence/need for support".

CONCLUSIONS

Our study found some overlap between the priorities of PWE, carers, and health professionals. They, however, highlight additional areas of importance to patients and carers. Our results could inform a core outcome set for epilepsy that represents the domains that should be reported as a minimum by all trials. This could promote trials which produce meaningful results and consistency in measurement and reporting.

Melatonin as add-on treatment for epilepsy

BACKGROUND

This is an updated version of the original Cochrane review published in Issue 6, 2012.Epilepsy is one of the most common chronic neurological disorders. Despite the plethora of antiepileptic drugs (AEDs) currently available, 30% of people continue having seizures. This group of people requires a more aggressive treatment, since monotherapy, the first choice scheme, fails to control seizures. Nevertheless, polytherapy often results in a number of unwanted effects, including neurological disturbances (somnolence, ataxia, dizziness), psychiatric and behavioural symptoms, and metabolic alteration (osteoporosis, inducement or inhibition of hepatic enzymes, etc.). The need for better tolerated AEDs is even more urgent in this group of people. Reports have suggested an antiepileptic role of melatonin with a good safety profile.

OBJECTIVES

To assess the efficacy and tolerability of melatonin as add-on treatment for epilepsy.

SEARCH METHODS

For the latest update, we searched the Cochrane Epilepsy Group's Specialized Register (12 January 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) via the Cochrane Register of Studies Online (CRSO, 12 January 2016), and MEDLINE (Ovid, 11 January 2016). We searched the bibliographies of any identified study for further references. We handsearched selected journals and conference proceedings. We applied no language restrictions. In addition, we contacted melatonin manufacturers (i.e. Nathura) and original investigators to identify any unpublished studies.

SELECTION CRITERIA

Randomized controlled trials; double, single, or unblinded trials; parallel group or cross-over studies. People with epilepsy regardless of age and gender, including children and adults with disabilities. Administration of melatonin as add-on treatment to any AED(s) compared to add-on placebo or no add-on treatment.

DATA COLLECTION AND ANALYSIS

Review authors independently selected trials for inclusion according to pre-defined criteria, extracted relevant data, and evaluated the methodological quality of trials. We assessed the following outcomes: at least 50% seizure reduction, seizure freedom, adverse events, and quality of life.

MAIN RESULTS

We included six publications, with 125 participants (106 aged under 18 years). Two different comparisons were available: melatonin versus placebo and melatonin 5 mg versus melatonin 10 mg. Despite our primary intention, due to insufficient information on outcomes, we were unable to perform any meta-analyses, but summarized data narratively. Four studies were randomized, double-blind, cross-over, placebo-controlled trials and two were randomized, double-blind, parallel, placebo-controlled trials. Only two studies provided the exact number of seizures during the trial compared to the baseline: none of the participants with seizures during the trial had a change in seizure frequency compared with the baseline. Two studies systematically evaluated adverse effects (worsening of headache was reported in a child with migraine under melatonin treatment). Only one study systematically evaluated quality of life, showing no statistically significant improvement in quality of life in the add-on melatonin group.

AUTHORS' CONCLUSIONS

Included studies were of poor methodological quality, and did not systematically evaluate seizure frequency and adverse events, so that it was impossible to summarize data in a meta-analysis. It is not possible to draw any conclusion about the role of melatonin in reducing seizure frequency or improving quality of life in people with epilepsy.

Potential safety issues in the use of the hormone melatonin in paediatrics

Melatonin is a hormone produced by the pineal gland during the night in response to light/dark information received by the retina and its integration by the suprachiasmatic nucleus. When administered to selected populations of adults, in particular those displaying delayed sleep phase disorder, melatonin may advance the time of sleep onset. It is, however, being increasingly prescribed for children with sleep disorders despite the fact that (i) it is not registered for use in children anywhere in the world; (ii) it has not undergone the formal safety testing expected for a new drug, especially long-term safety in children; (iii) it is known to have profound effects on the reproductive systems of rodents, sheep and primates, as well as effects on the cardiovascular, immune and metabolic systems; and (iv) there is the potential for important interactions with drugs sometimes prescribed for children. In this review, I discuss properties of melatonin outside its ability to alter sleep timing that have been widely ignored but which raise questions about the safety of its use in infants and adolescents.

Melatonin improves sleep in children with epilepsy: a randomized, double-blind, crossover study

OBJECTIVE

Insomnia, especially maintenance insomnia, is widely prevalent in epilepsy. Although melatonin is commonly used, limited data address its efficacy. We performed a randomized, double-blind, placebo-controlled, crossover study to identify the effects of melatonin on sleep and seizure control in children with epilepsy.

METHODS

Eleven prepubertal, developmentally normal children aged 6-11 years with epilepsy were randomized by a software algorithm to receive placebo or a 9-mg sustained release (SR) melatonin formulation for four weeks, followed by a one-week washout and a four-week crossover condition. The pharmacy performed blinding; patients, parents, and study staff other than a statistician were blinded. The primary outcomes were sleep onset latency and wakefulness after sleep onset (WASO) measured on polysomnography. The secondary outcomes included seizure frequency, epileptiform spike density per hour of sleep on electroencephalogram (EEG), and reaction time (RT) measures on psychomotor vigilance task (PVT). Statistical tests appropriate for crossover designs were used for the analysis.

RESULTS

Data were analyzed from 10 subjects who completed the study. Melatonin decreased sleep latency (mean difference, MD, of 11.4 min and p = 0.02) and WASO (MD of 22 min and p = 0.04) as compared to placebo. No worsening of spike density or seizure frequency was seen. Additionally, slow-wave sleep duration and rapid eye movement (REM) latency were increased with melatonin and REM sleep duration was decreased. These changes were statistically significant. Worsening of headache was noted in one subject with migraine on melatonin.

CONCLUSION

SR melatonin resulted in statistically significant decreases in sleep latency and WASO. No clear effects on seizures were observed, but the study was too small to allow any conclusions to be drawn in this regard.

Antioxidants as a preventive treatment for epileptic process: a review of the current status

Epilepsy is known as one of the most frequent neurological diseases, characterized by an enduring predisposition to generate epileptic seizures. Oxidative stress is believed to directly participate in pathways leading to neurodegeneration, which serves as the most important propagating factor, leading to the epileptic condition and cognitive decline. Moreover, there is also a growing body of evidence showing the disturbance of antioxidant system balance and consequently increased production of reactive species in patients with epilepsy. A meta-analysis, conducted in the present review confirms an association between epilepsy and increased lipid peroxidation. Furthermore, it was also shown that some of the antiepileptic drugs could potentially be responsible for additionally increased lipid peroxidation. Therefore, it is reasonable to propose that during the epileptic process neuroprotective treatment with antioxidants could lead to less sever structural damages, reduced epileptogenesis and milder cognitive deterioration. To evaluate this hypothesis studies investigating the neuroprotective therapeutic potential of various antioxidants in cells, animal seizure models and patients with epilepsy have been reviewed. Numerous beneficial effects of antioxidants on oxidative stress markers and in some cases also neuroprotective effects were observed in animal seizure models. However, despite these encouraging results, till now only a few antioxidants have been further applied to patients with epilepsy as an add-on therapy. Based on the several positive findings in animal models, a strong need for more carefully planned, randomized, double-blind, cross-over, placebo-controlled clinical trials for the evaluation of antioxidants efficacy in patients with epilepsy is warranted.

Meta-analyses in the wonderland of neurology

Meta-analyses are often misused and underused in neurology. This editorial provides some comments on the role of meta-analyses in neurological research. Recently, a huge increase in the number of meta-analyses and systematic reviews has been observed in neurological journals. The major strengths of meta-analyses are the increase of statistical power. However, as for any other investigative tool, meta-analytic research is a research method itself which can produce severe shortcomings. Specifically, the issues of search terms, time periods of published studies, databases used for searching, the definitions of inclusion and exclusion criteria for papers (which greatly affect clinical heterogeneity), publication bias; and the statistical methods used, dramatically influence the results of meta-analyses. The main problem of meta-analyses is that they cannot be expected to overcome the limitations of the studies they include (the so-called “garbage in, garbage out” phenomenon). Furthermore, most systematic reviews in the neurological literature lead to the unsatisfying and clinically frustrating statement “further studies are needed”. However it is much more frustrating to see how the gaps in scientific knowledge identified by meta-analyses have not been translated into serious efforts to fill them. Besides their role in evaluating efficacy and tolerability of drugs, meta-analyses may be used to assess diagnostic values of debatable clinical findings, as they represent powerful tools to try to answer questions not posed by individual studies and to settle controversies arising from conflicting claims.

Chronopharmacology of anti-convulsive therapy

Approximately one-third of patients with epilepsy continue to have seizures despite antiepileptic therapy. Many seizures occur in diurnal, sleep/wake, circadian, or even monthly patterns. The relationship between biomarkers and state changes is still being investigated, but early results suggest that some of these patterns may be related to endogenous circadian patterns whereas others may be related to wakefulness and sleep or both. Chronotherapy, the application of treatment at times of greatest seizure susceptibility, is a technique that may optimize seizure control in selected patients. It may be used in the form of differential dosing, as preparations designed to deliver sustained or pulsatile drug delivery or in the form of 'zeitgebers' that shift endogenous rhythms. Early trials in epilepsy suggest that chronopharmacology may provide improved seizure control compared with conventional treatment in some patients. The present article reviews chronopharmacology in the treatment of epilepsy as well as future treatment avenues.