Off-label low dose amitriptyline for insomnia disorder: Patient-reported outcomes.

PURPOSE: Low dose amitriptyline is prescribed off-label to improve sleep maintenance in patients with insomnia disorder. Data on treatment outcomes are limited. We aimed to assess patient-reported treatment effect and side effects of low dose amitriptyline for insomnia in routine care data. METHODS: Cross-sectional study: Seven hundred fifty-two consecutive patients with insomnia disorder having sleep maintenance problems were treated in an outpatient sleep clinic with low dose amitriptyline (10-20 mg based on self-titration). Treatment was intended to improve sleep maintenance. Before the planned follow-up consultation (approximately 6 weeks after start treatment) patients completed an online treatment evaluation questionnaire. Treatment (dose, adherence), sleep, fatigue, satisfaction and side effects were assessed by multiple-choice questions with room for free-text elaboration. RESULTS: 53.7% of the patients reported to use amitriptyline up to 10 mg/day, 42.9% used a self-increased dose of mostly 20 mg/day, while 3.5% had discontinued treatment. 73.9% of the total study population reported improvement of sleep maintenance, 31.3% improved sleep onset, 35.2% improved daytime fatigue, and 45.8% reported to be (very) satisfied with treatment results. 66.1% reported at least one side effect. The reported side effects were generally the already known side effects of amitriptyline. CONCLUSION: These patient-reported outcomes support the clinical observations that low dose amitriptyline improves sleep maintenance on the short term and that it is generally well tolerated. This further justifies randomized controlled trials in patients with insomnia disorder and sleep maintenance problems to assess the effectiveness and safety of low dose amitriptyline on the short and long term.

Efficacy and safety of melatonin for sleep onset insomnia in children and adolescents: a meta-analysis of randomized controlled trials.

OBJECTIVE: To evaluate the efficacy and safety of melatonin in the treatment of sleep onset insomnia in children and adolescents. METHODS: Electronic databases and bibliographies of relevant reports were searched for randomized, placebo-controlled, clinical trials that used melatonin in children and adolescents with sleep onset insomnia. The quality of the included studies was assessed by the Cochrane Collaboration's risk-of-bias method. The mean differences (MD) and the odds ratios (OR) with 95% confidence interval (CI) were estimated by a random-effects model. Primary outcomes were sleep onset time (SOT), drop-out for all causes and drop-out for adverse events. Secondary outcomes included dim light melatonin onset (DLMO), sleep onset latency (SOL), total sleep time (TST), light-off time, and wake-up time. RESULTS: Seven trials with 387 participants were finally included after a systematic search. The overall quality of the included studies was low to moderate. SOT in patients receiving melatonin advanced more than patients receiving placebo (MD = -0.62 h, 95% CI -0.80, -0.45), as well as DLMO (MD = -0.82 h, 95% CI -1.23, -0.41). No differences were found in the outcome of drop-out for all causes (OR = 1.51, 95% CI 0.57, 4.05) or drop-out for adverse events (OR = 3.35, 95% CI 0.13, 86.03). Severe adverse events, migraine, and mild generalized epilepsy were reported in two cases. SOL decreased and TST increased, MD = -0.36 h (95% CI -0.49, -0.24) and MD = 0.38 h (95% CI 0.09, 0.66), respectively. Light-off time and wake-up time did not differ significantly. CONCLUSIONS: Melatonin was an effective and tolerable drug in the short-term treatment of sleep onset insomnia in children and adolescents. More studies, especially in adolescents, are needed to investigate the efficacy and safety of melatonin.

Long-Term Melatonin Therapy for Adolescents and Young Adults with Chronic Sleep Onset Insomnia and Late Melatonin Onset: Evaluation of Sleep Quality, Chronotype, and Lifestyle Factors Compared to Age-Related Randomly Selected Population Cohorts.

The extent of continuance of melatonin therapy initiated in pre-pubertal children with chronic sleep onset insomnia (CSOI) was investigated in young adult life. Sleep timing, sleep quality, adverse events, reasons for cessation of therapy, and patient characteristics with regard to therapy regimen, chronotype and lifestyle factors possibly influencing sleeping behavior were assessed. With an online survey using questionnaires (Pittsburgh Sleep Quality Index, Insomnia Severity Index, Morningness-Eveningness Questionnaire, and Munich Chronotype Questionnaire), outcomes were measured and compared with age-related controls. These controls were extracted from published epidemiological research programs applying the same questionnaires. At the moment of the survey, melatonin was still continued by 27.3% of the patients, with a mean treatment duration of 10.8 years. The overall average treatment duration was 7.1 years. Sleep quality of both discontinued and persistent melatonin users did not deviate from controls. Sleep timing and chronotype scores indicated evening type preference in all responders. Adverse events were scarce but the perceived timing of pubertal development suggested a tendency towards delayed puberty in former and current users of melatonin. This study may underestimate the number of children that are able to stop using melatonin due to the response rate (47.8%) and appeal for continuing users. Sleep timing parameters were based on self-reported estimates. Control populations were predominantly students and were of varying nationalities. The statistical power of this study is low due to the limited sample size. Melatonin therapy sustained for 7.1 years does not result in substantial deviations of sleep quality as compared to controls and appears to be safe. The evening type preference suggests a causal relation with CSOI. This study shows that ten years after initiation of treatment with melatonin for CSOI, approximately 75% of the patients will have normal sleep quality without medication.

Low maternal melatonin level increases autism spectrum disorder risk in children.

BACKGROUND: It is assumed that autism spectrum disorder (ASD) is caused by a combination of de novo inherited variation and common variation as well as environmental factors. It often co-occurs with intellectual disability (ID). Almost eight hundred potential causative genetic variations have been found in ASD patients. However, not one of them is responsible for more than 1% of ASD cases. Low melatonin levels are a frequent finding in ASD patients. Melatonin levels are negatively correlated with severity of autistic impairments, it is important for normal neurodevelopment and is highly effective in protecting DNA from oxidative damage. Melatonin deficiency could be a major factor, and well a common heritable variation, that increases the susceptibility to environmental risk factors for ASD. ASD is already present at birth. As the fetus does not produce melatonin, low maternal melatonin levels may be involved. METHODS: We measured 6-sulfatoxymelatonin in urine of 60 mothers of a child with ASD and controls. RESULTS: 6-sulfatoxymelatonin levels were significantly lower in mothers with an ASD child than in controls (p = 0.012). CONCLUSIONS: Low parental melatonin levels could be one of the contributors to ASD and possibly ID etiology. Our findings need to be duplicated on a larger scale. If our hypothesis is correct, this could lead to policies to detect future parents who are at risk and to treatment strategies to ASD and intellectual disability risk.

Effects of Melatonin and Bright Light Treatment in Childhood Chronic Sleep Onset Insomnia With Late Melatonin Onset: A Randomized Controlled Study.

Study Objectives: Chronic sleep onset insomnia with late melatonin onset is prevalent in childhood, and has negative daytime consequences. Melatonin treatment is known to be effective in treating these sleep problems. Bright light therapy might be an alternative treatment, with potential advantages over melatonin treatment. In this study, we compare the effects of melatonin and bright light treatment with a placebo condition in children with chronic sleep onset insomnia and late melatonin onset. Methods: Eighty-four children (mean age 10.0 years, 61% boys) first entered a baseline week, after which they received melatonin (N = 26), light (N = 30), or placebo pills (N = 28) for 3 to 4 weeks. Sleep was measured daily with sleep diaries and actigraphy. Before and after treatment children completed a questionnaire on chronic sleep reduction, and Dim Light Melatonin Onset (DLMO) was measured. Results were analyzed with linear mixed model analyses. Results: Melatonin treatment and light therapy decreased sleep latency (sleep diary) and advanced sleep onset (sleep diary and actigraphy), although for sleep onset the effects of melatonin were stronger. In addition, melatonin treatment advanced DLMO and had positive effects on sleep latency and sleep efficiency (actigraphy data), and sleep time (sleep diary and actigraphy data). However, wake after sleep onset (actigraphy) increased with melatonin treatment. No effects on chronic sleep reduction were found. Conclusions: We found positive effects of both melatonin and light treatment on various sleep outcomes, but more and stronger effects were found for melatonin treatment.

Classical conditioning for preserving the effects of short melatonin treatment in children with delayed sleep: a pilot study.

Melatonin treatment is effective in treating sleep onset problems in children with delayed melatonin onset, but effects usually disappear when treatment is discontinued. In this pilot study, we investigated whether classical conditioning might help in preserving treatment effects of melatonin in children with sleep onset problems, with and without comorbid attention deficit hyperactivity disorder (ADHD) or autism. After a baseline week, 16 children (mean age: 9.92 years, 31% ADHD/autism) received melatonin treatment for 3 weeks and then gradually discontinued the treatment. Classical conditioning was applied by having children drink organic lemonade while taking melatonin and by using a dim red light lamp that was turned on when children went to bed. Results were compared with a group of 41 children (mean age: 9.43 years, 34% ADHD/autism) who received melatonin without classical conditioning. Melatonin treatment was effective in advancing dim light melatonin onset and reducing sleep onset problems, and positive effects were found on health and behavior problems. After stopping melatonin, sleep returned to baseline levels. We found that for children without comorbidity in the experimental group, sleep latency and sleep start delayed less in the stop week, which suggests an effect of classical conditioning. However, classical conditioning seems counterproductive in children with ADHD or autism. Further research is needed to establish these results and to examine other ways to preserve melatonin treatment effects, for example, by applying morning light.

Precision medicine in circadian rhythm sleep-wake disorders: current state and future perspectives.

In circadian rhythm sleep-wake disorders precision medicine is less developed than in other medical disciplines mainly because homeostatic sleep and circadian timing have a very complex phenotype with multiple genetic regulation mechanisms. However, biomarkers, phenotyping and psychosocial characteristics are increasingly used. Devices for polysomnography, actigraphy and sleep-tracking applications in mobile phones and other consumer devices with eHealth technologies are increasingly used. Also sleep-related questionnaires and the assessment of co-morbidities influencing sleep in circadian rhythm sleep-wake disorders are major contributors to precision sleep medicine. To further strengthen the (pharmaco-)genetic and biomarker pillar, technology needs to be evolved further. Routinely measuring treatment results using patient-reported outcome measures and clinical neurophysiological instruments will boost precision sleep medicine.

Sleep and Circadian Rhythmicity in Adult ADHD and the Effect of Stimulants.

OBJECTIVE: This review updates information on sleep and circadian rhythmicity in adult ADHD, especially circadian rhythmicity and the influence of stimulants. METHOD: Investigations into sleep, chronotype, and circadian rhythm in adult ADHD were searched in the Cochrane Library, Embase, Medline, and PsycInfo databases. RESULTS: ADHD in adults is associated with longer objective sleep latency, irrespective of insomnia complaints. Sleep maintenance is disturbed and waking up time is delayed. Adult ADHD is associated with increased eveningness, delayed dim light melatonin onset (DLMO), and later waking up time. Stimulant treatment induces delay of nonparametric circadian parameters, whereas light therapy (LT) induces shifts toward morningness, which is associated with a reduction of ADHD symptoms. CONCLUSION: Adult ADHD is associated with delayed circadian rhythmicity and analogous sleep characteristics, which are typical of a delayed sleep phase disorder. Stimulants induce delay of circadian rhythmicity.

Prevalence of Restless Legs Syndrome in Adult ADHD and Its Subtypes.

In this observational cross-sectional study, 49 subjects were assessed for sleep disorders and for ADHD symptoms. Thirty-six received an ADHD diagnosis (29: combined type (ADHD-C); 7: inattentive type). An RLS and RLS symptoms prevalence of 34.5% was found, with a higher prevalence rate in the ADHD-C subgroup, although not significantly (p = 0.066). RLS symptoms were correlated with particularly hyperactivity-impulsivity (ρ = 0.742; p: 0.000). ADHD patients with positive RLS scores reported higher scores on the ADHD-Rating scale compared with patients with negative RLS scores (Z: -2.968, p = 0.003), mainly due to higher hyperactivity-impulsivity scores (Z: -3.145; p = 0.002). Our findings show that clinicians need to be aware of RLS among adult ADHD patients, particularly those with severe hyperactivity-impulsivity symptoms.

Increased prevalence of restless legs syndrome in patients with Crohn's disease.

OBJECTIVE: To determine (a) the incidence of restless legs syndrome (RLS) in patients with Crohn's disease (CD), (b) whether and how the occurrence and severity of RLS is related to severity of CD, and (c) how RLS influences the quality of life of CD patients. BASIC METHODS: We carried out a cross-sectional questionnaire study in a random selection of 144 CD patients and 80 controls. Differences were calculated using a χ-test (categorical data), an independent T-test (continuous data, normal distribution), or a Mann-Whitney U-test (continuous data, non-normal distribution). Logistic regression analysis was carried out to establish the relation between CD and RLS after adjusting for risk factors. MAIN RESULTS: The prevalence of RLS was 25.7% (37/144) in CD patients compared with 12.5% (10/80) in the control group (P=0.02). CD patients using caffeine and patients with arthralgias had a higher risk for RLS. A higher score on the modified Harvey Bradshaw Index and CD-related surgery were also associated with a higher risk for RLS. CD-related surgery was also associated with a more severe course of RLS. Patients and controls with RLS had a lower score on 'physical functioning', one of the subcategories of the RAND-36 quality-of-life questionnaire. PRINCIPAL CONCLUSION: RLS occurs more frequently in patients with CD compared with healthy individuals. A more severe course of CD seems to be associated with a higher risk for RLS. The presence of RLS has a negative influence on quality of life, mainly interfering with physical activities of daily life.

Migraine associated with gastrointestinal disorders: review of the literature and clinical implications.

Recent studies suggest that migraine may be associated with gastrointestinal (GI) disorders, including irritable bowel syndrome (IBS), inflammatory bowel syndrome, and celiac disease. Here, an overview of the associations between migraine and GI disorders is presented, as well as possible mechanistic links and clinical implications. People who regularly experience GI symptoms have a higher prevalence of headaches, with a stronger association with increasing headache frequency. Children with a mother with a history of migraine are more likely to have infantile colic. Children with migraine are more likely to have experienced infantile colic compared to controls. Several studies demonstrated significant associations between migraine and celiac disease, inflammatory bowel disease, and IBS. Possible underlying mechanisms of migraine and GI diseases could be increased gut permeability and inflammation. Therefore, it would be worthwhile to investigate these mechanisms further in migraine patients. These mechanisms also give a rationale to investigate the effects of the use of pre- and probiotics in migraine patients.

Why the dim light melatonin onset (DLMO) should be measured before treatment of patients with circadian rhythm sleep disorders.

Treatment of circadian rhythm sleep disorders (CRSD) may include light therapy, chronotherapy and melatonin. Exogenous melatonin is increasingly being used in patients with insomnia or CRSD. Although pharmacopoeias and the European food safety authority (EFSA) recommend administering melatonin 1-2 h before desired bedtime, several studies have shown that melatonin is not always effective if administered according to that recommendation. Crucial for optimal treatment of CRSD, melatonin and other treatments should be administered at a time related to individual circadian timing (typically assessed using the dim light melatonin onset (DLMO)). If not administered according to the individual patient's circadian timing, melatonin and other treatments may not only be ineffective, they may even result in contrary effects. Endogenous melatonin levels can be measured reliably in saliva collected at the patient's home. A clinically reliably DLMO can be calculated using a fixed threshold. Diary and polysomnographic sleep-onset time do not reliably predict DLMO or circadian timing in patients with CRSD. Knowing the patient's individual circadian timing by assessing DLMO can improve diagnosis and treatment of CRSD with melatonin as well as other therapies such as light or chronotherapy, and optimizing treatment timing will shorten the time required to achieve results.

Termination of short term melatonin treatment in children with delayed Dim Light Melatonin Onset: effects on sleep, health, behavior problems, and parenting stress.

OBJECTIVE: To investigate the effects of termination of short term melatonin treatment on sleep, health, behavior, and parenting stress in children with delayed Dim Light Melatonin Onset. METHODS: Forty-one children (24 boys, 17 girls; mean age=9.43 years) entered melatonin treatment for 3 weeks and then discontinued treatment by first taking a half dose for 1 week and then stopping completely for another week. Sleep was measured with sleep diaries filled in by parents and with actometers worn by children. Analyses were conducted with linear mixed models. RESULTS: Sleep latency was longer during the stop week compared to the treatment weeks. Sleep start was later and actual sleep time was shorter during the half dose and stop weeks compared to the treatment weeks. Sleep efficiency deteriorated in the stop week. Dim Light Melatonin Onset was earlier after treatment, but this effect disappeared after the stop week. In addition to the effects on sleep, results from questionnaires completed by parents showed that melatonin treatment also had positive effects on children's health and behavior problems and parenting stress. While health deteriorated after treatment discontinuation, the effects on behavior problems and parenting stress remained. Behavior problems at baseline did not influence the effect of melatonin treatment. CONCLUSIONS: This study showed that complete termination of treatment after 4 weeks of melatonin use was too early. However, clinicians may advise a lower dose after a successful treatment trial of several weeks.

Psychometric properties of a sleep questionnaire for use in individuals with intellectual disabilities.

We examined the psychometric properties of one part of the Sleep Questionnaire developed by Simonds and Parraga (SQ-SP; 1982), a questionnaire that is frequently used to explore sleep problems and behaviors related to sleep in individuals with intellectual disability (ID). The SQ-SP was completed for 345 individuals with ID (sleep clinic n = 146; control group n = 103; published studies n = 68; psychiatric clinic n = 28). Internal consistency was good (Cronbach's α = .80) and test-retest reliability for the total SQ-SP score was also good (Spearman's rank correlation = .83, p<.01). Convergent validity was adequate (r = .79, p<.001) and concurrent validity was satisfactory (r = .52, p<.001). Exploratory factor analysis suggested a 5-factor structure (Snoring, Daytime sleepiness, Complaints related to sleep, Sleep apnea and Anxiety related to sleep). Internal consistency of the five factors ranged from modest (Cronbach's α = .57) to good (Cronbach's α = .82). Confirmatory factor analysis corroborated the 5-factor structure. The Composite Sleep Index, the total SQ-SP score and the factor scores on Daytime Sleepiness and Complaints related to sleep were able to differentiate the control group from the sleep clinic group. The SQ-SP appears to be a reliable and valid tool in assessing sleep and different types of sleep disturbance in individuals with ID.

Evaluation of salivary melatonin measurements for Dim Light Melatonin Onset calculations in patients with possible sleep-wake rhythm disorders.

BACKGROUND: Dim Light Melatonin Onset (DLMO) can be calculated within a 5-point partial melatonin curve in saliva collected at home. We retrospectively analyzed the patient melatonin measurements sample size of the year 2008 to evaluate these DLMO calculations and studied the correlation between diary or polysomnography (PSG) sleep onset and DLMO. METHODS: Patients completed an online questionnaire. If this questionnaire pointed to a possible Delayed Sleep Phase Disorder (DSPD), saliva collection devices were sent to the patient. Collection occurred at 5 consecutive hours. Melatonin concentration was measured with a radioimmunoassay and DLMO was defined as the time at which the melatonin concentration in saliva reaches 4 pg/mL. Sleep onset time was retrieved from an online one-week sleep diary and/or one-night PSG. RESULTS: A total of 1848 diagnostic 5-point curves were obtained. DLMO could be determined in 76.2% (n=1408). DLMO significantly differed between different age groups and increased with age. Pearson correlations (r) between DLMO and sleep onset measured with PSG or with a diary were 0.514 (p=<0.001, n=54) and 0.653 (p=0.002, n=20) respectively. CONCLUSION: DLMO can be reliably measured in saliva that is conveniently collected at home. DLMO correlates moderately with sleep onset.

Evaluation of sleep, puberty and mental health in children with long-term melatonin treatment for chronic idiopathic childhood sleep onset insomnia.

OBJECTIVES: To establish whether long-term use of melatonin influences pubertal development, sleep quality and mental health development in children as compared with the normal Dutch population of the same age. METHODS: This follow-up research study was conducted in children included in a previous melatonin dose-finding trial. Outcomes were measured using questionnaires (Strength and Difficulties Questionnaire (SDQ), Children's Sleep Habits Questionnaire (CSHQ) and Tanner Stages) adopted for Dutch children. Mean duration of therapy, persistence of effect, adverse events and (other) reasons leading to cessation of therapy were additional objectives of this study. RESULTS: Mean years of usage (n=51) was 3.1 years (min 1.0 year, max 4.6 years), mean dose 2.69 mg (min 0.3 mg, max 10 mg). Mean SDQ score, mean CSHQ score and Tanner Stages standard deviation scores did not differ in a statistically significant way from published scores of the general Dutch population of the same age and sex. CONCLUSIONS: This follow-up study demonstrates that melatonin treatment in children can be sustained over a long period of time without substantial deviation of the development of children with respect to sleep quality, puberty development and mental health scores, as compared with the general Dutch population.

The use of exogenous melatonin in delayed sleep phase disorder: a meta-analysis.

STUDY OBJECTIVES: To perform a meta-analysis of the efficacy and safety of exogenous melatonin in advancing sleep-wake rhythm in patients with delayed sleep phase disorder. DESIGN: Meta analysis of papers indexed for PubMed, Embase, and the abstracts of sleep and chronobiologic societies (1990-2009). PATIENTS: Individuals with delayed sleep phase disorder. INTERVENTIONS: Administration of melatonin. MEASUREMENTS AND RESULTS: A meta-analysis of data of randomized controlled trials involving individuals with delayed sleep phase disorder that were published in English, compared melatonin with placebo, and reported 1 or more of the following: endogenous melatonin onset, clock hour of sleep onset, wake-up time, sleep-onset latency, and total sleep time. The 5 trials including 91 adults and 4 trials including 226 children showed that melatonin treatment advanced mean endogenous melatonin onset by 1.18 hours (95% confidence interval [CI]: 0.89-1.48 h) and clock hour of sleep onset by 0.67 hours (95% CI: 0.45-0.89 h). Melatonin decreased sleep-onset latency by 23.27 minutes (95% CI: 4.83 -41.72 min). The wake-up time and total sleep time did not change significantly. CONCLUSIONS: Melatonin is effective in advancing sleep-wake rhythm and endogenous melatonin rhythm in delayed sleep phase disorder.

Dose finding of melatonin for chronic idiopathic childhood sleep onset insomnia: an RCT.

RATIONALE: Pharmacokinetics of melatonin in children might differ from that in adults. OBJECTIVES: This study aims to establish a dose-response relationship for melatonin in advancing dim light melatonin onset (DLMO), sleep onset (SO), and reducing sleep onset latency (SOL) in children between 6 and 12 years with chronic sleep onset insomnia (CSOI). METHODS: The method used for this study is the randomized, placebo-controlled double-blind trial. Children with CSOI (n = 72) received either melatonin 0.05, 0.1, and 0.15 mg/kg or placebo during 1 week. Sleep was assessed with log and actigraphy during this week and the week before. Outcomes were the shifts in DLMO, SO, and SOL. RESULTS: Treatment with melatonin significantly advanced SO and DLMO by approximately 1 h and decreased SOL by 35 min. Within the three melatonin groups, effect size was not different, but the circadian time of administration (TOA) correlated significantly with treatment effect on DLMO (r (s) = -0.33, p = 0.022) and SO (r (s) = -0.38, p = 0.004), whereas clock TOA was correlated with SO shift (r = -0.35, p = 0.006) and not with DLMO shift. CONCLUSIONS: No dose-response relationship of melatonin with SO, SOL, and DLMO is found within a dosage range of 0.05-0.15 mg/kg. The effect of exogenous melatonin on SO, SOL, and DLMO increases with an earlier circadian TOA. The soporific effects of melatonin enhance the SO shift. This study demonstrates that melatonin for treatment of CSOI in children is effective in a dosage of 0.05 mg/kg given at least 1 to 2 h before DLMO and before desired bedtime.

Loss of response to melatonin treatment is associated with slow melatonin metabolism.

BACKGROUND: In some of our patients with intellectual disability (ID) and sleep problems, the initial good response to melatonin disappeared within a few weeks after starting treatment, while the good response returned only after considerable dose reduction. The cause for this loss of response to melatonin is yet unknown. We hypothesise that this loss of response is associated with slow melatonin metabolism. METHOD: In this study, we determined melatonin clearance in two female (aged 61 and 6 years) and one male (aged 3 years) patients who had chronic insomnia, late melatonin onset and mild ID, and whose sleep quality worsened a few weeks after initial good response to melatonin treatment, suggesting melatonin tolerance. After a 3-week washout period, patients received melatonin 1.0, 0.5 or 0.1 mg, respectively. Salivary melatonin level was measured just before melatonin administration, and 2 and 4 h thereafter. After this melatonin clearance test, melatonin treatment was resumed with a considerably lower dose. RESULTS: In all patients melatonin concentrations remained >50 pg/mL at 2 and 4 h after melatonin administration. After resuming melatonin treatment sleep problems disappeared. The same procedure was followed in three patients who did not show loss of response to melatonin after 6 months of treatment. In all patients in the control group melatonin concentrations decreased between 2 and 4 h after melatonin administration with a mean of 83%. CONCLUSION: We hypothesise that loss of response to melatonin treatment can be caused by slow metabolisation of exogenous melatonin. As melatonin is metabolised in the liver almost exclusively by cytochrome P450 enzyme CYP1A2, this slow melatonin metabolism is probably due to decreased activity/inducibility of CYP1A2. In patients with loss of response to melatonin, a melatonin clearance test should be considered and a considerably dose reduction is advised.

Automated genomic DNA extraction from saliva using the QIAxtractor.

BACKGROUND: Venipuncture is an invasive procedure to obtain whole blood in order to obtain high quality and sufficient amounts of genomic DNA. Obtaining DNA from non-invasive sources is preferred by patients, medical doctors and researchers. Saliva collected with cotton swabs (Salivette) is increasingly being used to study chemical compounds, and it can also be a source of DNA. However, extracting DNA from Salivettes is very laborious and time consuming. Therefore, we developed a protocol for automated genomic DNA extraction from saliva collected in Salivette using the QIAxtractor. METHODS: Saliva (0.1-2.0 mL) was collected by chewing on a Salivette for 1-2 min. A total of 70 samples, collected from healthy volunteers, were extracted with the QIAxtractor robot and a Qiagen DX reagent pack. Quantity and quality was assessed using UV spectrometry and real-time polymerase chain reaction (PCR) (substitution at position -729 in the CYP1A2 gene). RESULTS: The average DNA concentration from the saliva samples was 6.0 microg/mL (95% CI 5.4-6.6 microg/mL). In 100% of the saliva samples, PCR products were detected with an average cycle threshold of 23.1 (95% CI 22.6-23.6). CONCLUSIONS: DNA can be extracted in sufficient amounts from Salivette with a fully automated system with a short turnaround time. Real-time PCR can be performed with these samples.