Monitoring salivary melatonin concentrations in children with sleep disorders using liquid chromatography-tandem mass spectrometry.

BACKGROUND: Melatonin is synthesized in the pineal gland and is an important circadian phase marker, especially in the determination of sleep patterns. Both temporary and permanent abnormal sleep patterns occur in children; therefore, it is desirable to have methods for monitoring melatonin in biological fluids in the diagnosis and treatment of such disorders. OBJECTIVE: The objective of the study is to develop a liquid chromatography-tandem mass spectrometry method for the determination of melatonin in saliva and to apply it to monitoring salivary concentrations in children with sleep disorders. METHODS: A deuterated internal standard (d7-melatonin) was added to a diluted saliva sample (20 µL) in an autosampler vial insert, and 50 µL were injected. Plasticware was strictly avoided, and all glassware was scrupulously cleaned and then baked at 120°C for at least 48 hours to obtain satisfactory performance. Reverse-phase chromatography was performed on a C8 column using a linear gradient elution profile comprising mobile phases A (0.1% aqueous formic acid) and B (15% methanol in acetonitrile containing 0.1% formic acid), pumped at a total flow rate of 0.8 mL/min. The run time was 8 minutes. After atmospheric pressure chemical ionization, mass spectrometric detection was in positive ion mode. Mass detection was by selected reaction monitoring mode with the following mass transitions used for quantification: melatonin, m/z 233.0 → 173.8 and d7-melatonin, m/z 240.0 → 178.3. RESULTS: Linearity (r > 0.999) was established from 3.9 to 1000 pg/mL. Imprecision (coefficient of variation percent) was less than 11%, and accuracy was 100-105% (7.0-900 pg/mL). The method was selective, and the mean (range) ratio of the slopes of calibrations in water to those in daytime saliva samples collected from 10 healthy adult subjects was 0.989 (0.982-0.997), indicating negligible matrix effects. The application of the assay was demonstrated in healthy adults and in children being clinically investigated for sleep disturbances. CONCLUSIONS: A validated liquid chromatography-tandem mass spectrometry method suitable for monitoring salivary melatonin in children with circadian rhythm sleep disorders is reported. The method also has potential application to pediatric population pharmacokinetic studies using sparse sampling of saliva as the biological sample matrix.

Patient concerns regarding antidepressant drug–drug interactions: a retrospective analysis using data from a medicines call centre.

Introduction Antidepressant use has increased over the last two decades, with Australia and New Zealand among the highest antidepressant users in Organisation for Economic Co-operation and Development (OECD) countries. Comorbidity and polypharmacy are common in antidepressant users, increasing the likelihood of interaction-related adverse drug events, which are frequently preventable. Aim We aimed to identify, profile, and analyse potential antidepressant drug-drug interactions in information-seeking antidepressant users. Methods We retrospectively analysed antidepressant-related drug-drug interaction enquiries from patients or carers who contacted a pharmacist-led Australian national medicines call centre over an 8-year period to determine patient characteristics, concomitant drugs involved, prevalence and type of antidepressant-related drug-drug interaction across life stages, and associated risks. Results Of 3899 antidepressant drug-drug interaction calls, the most frequent concomitant drugs were antipsychotics, opioids, benzodiazepines, and complementary medicines. Narrative analyses of 2011 calls identified 81.0% of patients with potential drug-drug interactions and 10.4% categorised with worrying symptoms. The most frequent drug-drug interaction risks were excessive sedation, increased anticholinergic effects, serotonin syndrome, and suicidal thoughts. Carers of children aged Discussion Antidepressant users often have information gaps and safety concerns regarding drug-drug interactions that motivate help-seeking behaviour. Symptoms and drug-drug interaction consequences may be underestimated in these patients. Primary care health professionals have a role in proactively addressing the risk of drug-drug interactions to support benefit-risk assessment and shared decision-making.

Melatonin for non-respiratory sleep disorders in visually impaired children.

BACKGROUND: Exogenous melatonin helps in regulating the circadian rhythm and is widely used for the management of sleep disorders in visually impaired children. OBJECTIVES: The aim of the review was to assess melatonin therapy for treatment of non-respiratory sleep disorders in visually impaired children, with regard to improvement in sleep habit, sleep scheduling and sleep maintenance, when compared with placebo or no treatment. SEARCH METHODS: We searched the following databases between February 2011 and July 2011: the Cochrane Central Register of Controlled Trials (CENTRAL) 2011(1) searched on 4th February 2011; MEDLINE (1950 to June Week 3, 2011) searched on 20th June 2011; EMBASE (1980 to June Week 4, 2011) searched on 7th July 2011; CINAHL (1937 to 21 September 2011); the metaRegister of Controlled Trials (this includes ClinicalTrial.gov) searched 20 July 2011, and reference lists of papers identified after initial screening. SELECTION CRITERIA: We planned to include randomized controlled trials (RCTs) and quasi-RCTs, including cross-over studies. Treatment would be exogenous melatonin. Control groups could be placebo, other medication for sleep disorders or no treatment. Outcomes sought were improved sleep with regard to timing and duration, quality of life and adverse events. DATA COLLECTION AND ANALYSIS: Three review authors independently assessed trials for inclusion in the review. MAIN RESULTS: We did not find any studies fulfilling the inclusion criteria, therefore no outcome data are reported.We identified nine studies after initial screening and, after further evaluation, we excluded these. The excluded studies involved a total of 163 individuals aged two years to 18 years. We excluded studies for three main reasons: they were non-randomized or case series studies, they were studies of people over 18 years of age or even where the study was randomised, the study population was mixed and results pertaining to the visually impaired cohort could not be independently evaluated. No significant adverse effects of melatonin were reported in these excluded studies. AUTHORS' CONCLUSIONS: There is currently no high quality data to support or refute the use of melatonin for sleep disorders in visually impaired children. Placebo-controlled trials examining important clinical outcomes such as sleep quality, sleep latency, duration of sleep and night-time awakenings are needed. As the numbers of children meeting study inclusion criteria are likely to be low at individual sites, multicentre collaboration between developmental paediatricians, sleep physicians and other health care professionals is essential to achieve sufficient sample size for controlled studies. Such collaboration would help facilitate local recruitment at multiple sites, with study oversight being provided by paediatricians with expertise in sleep disorders. Participation of collaborators with experience in evidence-based practice research is also desirable due to the lack of protocols on melatonin therapy in the target population.

Anaemia in patients undergoing major bowel surgery - Prevalence and current practice: A public and private institution experience.

AIM: The study aimed to compare the frequency and alignment of preoperative anaemia screening and treatment with Australian guidelines in elective bowel surgery and determine the impact on clinical outcomes. METHODS: We performed a retrospective observational study, with an audit of 559 adult patients who underwent major elective bowel surgery in an Australian metropolitan hospital, January 2016-December 2018. Outcome measures included rate of anaemia, guideline compliance, hospital length of stay, and transfusion rate. RESULTS: Preoperative anaemia assessment occurred in 82.6% of patients. However, only 5.2% received recommended biochemical tests at least one week before surgery. Only 25.2% of anaemic patients received preoperative treatment; they experienced a longer hospital length of stay (9.93 days versus 7.88 days, p < 0.001) and an increased rate of transfusion (OR: 3.186, p < 0.05). CONCLUSION: The gaps between current preoperative anaemia screening, management and national guidelines may place patients at higher risk of poor surgical outcome.

Does consumer medicines interest reflect medicines use? An observational study comparing medicines call center queries with medicines use.

BACKGROUND: Consumers have questions about their medication but the nature of these concerns and how they reflect medication use is unknown. OBJECTIVES: To determine the characteristics and medicines interests of callers to an Australian medicines call center and whether the medicines interest of callers corresponds with medicines utilization. METHODS: Data from consumers who contacted a national medicines call center between September 2002 and June 2010 were analyzed. Patterns of consumer medicines interest were described. Medicines were class-matched by Anatomical Therapeutic Classification, and compared with dispensed use (January 2006-June 2010). RESULTS: In total 125,951 calls were received between 2002 and 2010. Callers were mainly female (76.8%), median age 48 years, calling for themselves (71.7%). Motivation to call related to safety (34.7%), efficacy (24.1%) and interactions (14.9%). For the comparison with medicines utilization, 85,416 calls with 124,177 individual medicine counts were analyzed (2006 and 2010). There were 976 unique 'medicines of interest'. Half (49.4%) of these questions involved just fifty unique medicines. Nervous system medicines (antiepileptics, psycholeptics, analgesics) and antibacterials consistently ranked highest for interest compared with use. Conversely, agents acting on the renin-angiotensin system, statins and drugs for acid related disorders ranked low for interest despite widespread use. CONCLUSIONS: Consumer questions about medicines correlate poorly with overall medicines utilization. To promote quality health outcomes, clinicians should target their education to the relatively small number of medicines of real concern to patients.

An antibody to the beta-secretase cleavage site on amyloid-beta-protein precursor inhibits amyloid-beta production.

Proteolytic cleavage of amyloid-beta-protein precursor (AbetaPP) by beta- and gamma-secretases results in production of the amyloid-beta peptide (Abeta) that accumulates in the brains of sufferers of Alzheimer's disease (AD). We have developed a monoclonal antibody, 2B12, which binds in the vicinity of the beta-secretase cleavage site on AbetaPP but does not bind within the Abeta region. We hypothesised that this antibody, directed against the substrate rather than the enzyme, could inhibit cleavage of AbetaPP by beta-secretase via steric hindrance and thus reduce downstream production of Abeta. The antibody would enter cells by binding to AbetaPP when it is at the cell surface and then be internalised with the protein. We subsequently demonstrated that, after addition of 2B12 to standard growth media, this antibody was indeed capable of inhibiting Abeta40 production in neuroblastoma and astrocytoma cells expressing native AbetaPP, as measured by an ELISA. This inhibition was both concentration- and time-dependent and was specific to 2B12. We were only able to inhibit approximately 50% of Abeta40 production suggesting that not all AbetaPP is trafficked to the cell surface. We propose that this antibody could be used as a novel, putative therapy for the treatment of AD.

Co-administration of fluoxetine and WAY100635 improves short-term memory function.

The aim of this study was to determine whether the action of the antidepressant fluoxetine or the anxiolytic buspirone could be modified by specific 5-hydroxytriptamine (5-HT(1A)) receptor blockade in a short-term memory paradigm. Male Wistar rats were trained to perform the putative short-term memory task, delayed non-matching to position. WAY100635, a selective 5-HT(1A) receptor antagonist (0.15 mg/kg), was administered 15 min before either the selective serotonin reuptake inhibitor fluoxetine (3 mg/kg), or the partial 5-HT(1A) receptor agonist and dopamine D2 receptor antagonist, buspirone (0.3 mg/kg). 8-Hydroxy-di-n-propylamino tetralin (8-OH-DPAT), a full 5-HT(1A) receptor agonist (0.3 mg/kg), was also included in the study as a positive control. WAY100635 alone had no effect on any behavioural parameter measured (response accuracy, delay lever press activity and trial completion). 8-OH-DPAT impaired response accuracy in a delay-dependent manner, an effect reversed by WAY100635. Fluoxetine also impaired response accuracy delay-dependently. WAY100635 pretreatment not only reversed this deficit but improved response accuracy, in the presence of a significant deficit in trial completion. At the dose used, buspirone showed no significant differences compared to the control group. The data suggest that fluoxetine impairs short-term memory function by the indirect activation of 5-HT(1A) receptors, but that its co-administration with WAY100635 improves short-term memory function.

Does the human leukaemia differentiation factor fragment HLDF6 improve memory via brain DNA and protein synthesis?

The novel human differentiating factor peptide fragment HLDF6 (Thr-Gly-Glu-Asn-His-Arg) was synthesized and purified. HLDF6 (0.1mg/kg i.p. but not 1mg/kg i.p.) improved not only long-term (24h) memory in adult rats in the water maze behavioural paradigm but also performance in the delayed matching-to-position (DMTP) task (0.3 and 1.0 but not 0.1mg/kg i.p). Hence, HLDF6 not only enhanced allocentric spatial learning and reference memory (water maze) but also improved temporal, spatial and working memory processes in the DMTP behavioural paradigm. Immunoreactivity blotting analysis of HLDF (the protein precursor of HLDF6) was performed and the following rank order of visual intensities from brain structures was noted: hippocampus cerebral cortex cerebellum hypothalamus striatum. Subsequently, we found that the highest absolute levels of HLDF were expressed in the hippocampus and cerebral cortex as detected by ELISA. We also demonstrated that HLDF6 enhanced [(3)H]-thymidine and [(14)C]-leucine incorporation into whole brain and hippocampal homogenates (maxima occurring within the range 10 (-12)-10 (-6) M) suggesting that this hexapeptide promoted de novo DNA and protein biosynthesis. We discuss this data in terms of their implications for links with other integrative metabolic pathways involving immediate early gene activation which may underpin a potential application for HLDF6 in limiting memory impairments associated with neurodegenerative diseases.

Dopamine Agonists: Time Pattern of Adverse Effects Reporting in Australia.

BACKGROUND: In Australia, there is voluntary reporting of suspected adverse events (AEs) of therapeutic medicines. Some dopamine agonists (DAs) have serious AEs. OBJECTIVE: We aimed to explore the pattern of DA AE reporting over two decades. METHODS: We analysed AE case line listings obtained from the Australian Committee on the Safety of Medicines (ACSOM) for bromocriptine, cabergoline, pergolide, pramipexole and ropinirole, and related these to drug utilisation data (1992-2012). We noted the AE nature, frequency, onset, novelty, severity and outcome. RESULTS: The 220 suspected AEs fell into five categories: (i) syncopal/pre-syncopal, (ii) fibrotic, (iii) psychotic, (iv) obsessive-compulsive behaviours (OCB) and (v) increased sleep. There were differential lag times between initial individual drug registration and reporting of suspected AEs, with a lag of at least one year for fibrotic reactions and OCB compared to more contemporaneous reporting of other AEs. Consistent with the published literature, ACSOM data showed that ergot DAs share fibrotic reactions as a class AE, whereas symptomatic hypotensive reactions, psychosis and OCB occurred in both ergot and non-ergot DAs, cabergoline and pramipexole, respectively. Reports of syncopal and pre-syncopal reactions seemed to diminish as ergot-based DA use declined. Levodopa was taken simultaneously with DAs in 87 instances. Of those treated, 92 % were 50 years or older. Parkinson's disease accounted for 89 % of use (119 reports). CONCLUSIONS: Exploring the temporal relationship between post-marketing AE reporting and utilisation data, as exemplified by DAs, can be a valuable pharmacovigilance tool to encourage targeted adverse event monitoring and reporting.

Buspirone differentially modifies short-term memory function in a combined delayed matching/non-matching to position task.

This study investigated the action of 5-hydroxytryptamine (5-HT) mimetics on short-term memory function. The objective was to determine whether two closely related tasks could differentiate between partial 5-HT(1A) receptor activation, full 5-HT(1A) receptor activation and generalised enhanced serotonin (5-HT) activity. Male hooded Lister rats were trained to perform an operant-based combined delayed matching/non-matching to position task. Drugs used were: fluoxetine (3 mg/kg, i.p.), a selective 5-HT reuptake inhibitor; the full 5-HT(1A) receptor agonist, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT; 0.3 mg/kg, s.c.); and the partial 5-HT(1A) receptor agonist, buspirone (1 mg/kg, i.p.). Buspirone differentially disrupted response accuracy depending on the style of trial. There was no such difference in the case of 8-OH-DPAT, which impaired accuracy in both delayed matching/non-matching to position task, while fluoxetine affected neither. Thus, the findings suggest that partial 5-HT(1A) receptor activation compromises cognitive function to a greater extent than full 5-HT(1A) receptor activation, although a dopaminergic component cannot be excluded since buspirone possesses some dopamine D2 receptor antagonist activity. Furthermore, it suggests that there is a differential role for 5-HT in these two closely related behavioural tasks.

Morphine, cocaine and antidepressant induced motivational activity and midbrain dopaminergic neurotransmission.

Positive motivational properties of opioids, stimulants and serotonin selective reuptake inhibitors have been reported following place preference conditioning. The possibility that these effects are associated with changes in dopamine concentration in the nucleus accumbens or striatum was investigated. Male Wistar rats were place conditioned in a three compartment model to vehicle or drug (morphine 2.5 mg/kg, cocaine 5 mg/kg, sertraline 5 mg/kg or paroxetine 15 mg/kg) alternately for 8 days using a 30 min pre-treatment time. Control animals received saline only. Nucleus accumbens and striatal tissue were dissected 72 h after final drug dose, and the concentration of dopamine and its metabolites determined using high performance liquid chromatography (HPLC). Striatal dopamine D1-like receptor density was also determined through radioligand binding. Significant place preference (P<0.05) was observed with morphine, cocaine and sertraline. Morphine treated subjects showed a significant decrease (P<0.05) in striatal dopamine concentration, whilst cocaine and sertraline treatment resulted in a significant increase in striatal dopamine levels. Nucleus accumbens concentrations of dopamine, and striatal dopamine D1-like receptor density remained unchanged. The changes in striatal dopamine concentrations are consistent with withdrawal from opioid and stimulant compounds, and suggest that place preference conditioning may, in part, result from negative motivational or aversive effects.

Therapeutic options in the management of sleep disorders in visually impaired children: a systematic review.

BACKGROUND: Treatment of sleep disorders in visually impaired children is complicated by a complex pathophysiology, a high incidence of sleep disorders in this population, and a dearth of management options. The significant impact on the health of these children and distress to their caregivers warrant a systematic assessment of the published literature on therapeutic approaches. OBJECTIVE: This systematic review aims to assess the current therapeutic options in the management of sleep disorders in visually impaired children to identify knowledge gaps and guide future research. METHODS: A search of primary literature was conducted using the bibliographic databases PubMed (1980-August 2010), EMBASE (1990-August 2010), Science Citation Index Expanded (1990-August 2010), and CINHAL (1992-August 2010) and the Cochrane Central Register of Controlled Trials (CENTRAL). Additional studies were identified through snowballing search techniques (manually by searching retrieved references and electronically by using citation-tracking software). Search terms included behavioral treatment, children, circadian rhythm, hypnosedatives, intellectual disability, light therapy, melatonin, phototherapy, random allocation, randomized controlled trial (RCT), sleep disorder, and visual impairment. Randomized and quasi-randomized clinical trials of therapeutic options (behavioral treatment, light therapy, melatonin, or hypnosedatives) used in participants aged 3 months to 18 years who had both a visual impairment and a sleep disorder were included. Independent extraction of articles was performed by 2 authors using predefined data fields, including quality of the therapeutic options, based on the Strength of Recommendation Taxonomy evidence-rating system. RESULTS: Two RCTs were retrieved for melatonin, with improved effect on sleep latency (P = 0.019 and P < 0.05, respectively). However, separate analysis for visual impairment was not conducted. No RCTs were retrieved for behavioral intervention, light therapy, or hypnosedatives. Three studies using behavioral therapy (2 case reports and 1 case series) anecdotally showed improvement in sleep habit. No improvement in sleep rhythm was observed with a case series applying light therapy as an intervention. CONCLUSIONS: Children with visual impairment and sleep disorders are a heterogeneous patient group, making diagnosis and treatment difficult. RCTs on treatment options remain in their infancy, with a lack of evidence for appropriate therapeutic strategies. Trials across a range of selected diagnoses need to be conducted with adequate sample populations to differentiate the efficacy of 4 different treatment modalities (behavioral therapy, light therapy, melatonin, and hypnosedatives) as agents for improving sleep.

Prolonged anticholinergic delirium following antihistamine overdose.

OBJECTIVE: A case of anticholinergic delirium in a female adolescent is described, exploring the pharmacokinetic reasons for the prolonged time course and reviewing the management provided. CONCLUSION: A 14 year old female hospitalised for depression ingested large quantities of promethazine and cyproheptadine. A severe anticholinergic delirium ensued which resolved after six days, much longer than the expected duration. The likely cause of the prolonged delirium was the interaction of promethazine and fluvoxamine through the inhibition of the CYP2D6 enzyme. The patient's young age, the severity of the poisoning and the use of drugs with anticholinergic properties to manage the delirium may also have contributed. The delirium may have been reversed had a cholinesterase inhibitor been provided soon after the overdose.