Phenotypic and functional assessment of two novel KCNQ2 gain-of-function variants Y141N and G239S and effects of amitriptyline treatment.

While loss-of-function (LoF) variants in KCNQ2 are associated with a spectrum of neonatal-onset epilepsies, gain-of-function (GoF) variants cause a more complex phenotype that precludes neonatal-onset epilepsy. In the present work, the clinical features of three patients carrying a de novo KCNQ2 Y141N (n â€‹= â€‹1) or G239S variant (n â€‹= â€‹2) respectively, are described. All three patients had a mild global developmental delay, with prominent language deficits, and strong activation of interictal epileptic activity during sleep. Epileptic seizures were not reported. The absence of neonatal seizures suggested a GoF effect and prompted functional testing of the variants. In vitro whole-cell patch-clamp electrophysiological experiments in Chinese Hamster Ovary cells transiently-transfected with the cDNAs encoding Kv7.2 subunits carrying the Y141N or G239S variants in homomeric or heteromeric configurations with Kv7.2 subunits, revealed that currents from channels incorporating mutant subunits displayed increased current densities and hyperpolarizing shifts of about 10 â€‹mV in activation gating; both these functional features are consistent with an in vitro GoF phenotype. The antidepressant drug amitriptyline induced a reversible and concentration-dependent inhibition of current carried by Kv7.2 Y141N and G239S mutant channels. Based on in vitro results, amitriptyline was prescribed in one patient (G239S), prompting a significant improvement in motor, verbal, social, sensory and adaptive behavior skillsduring the two-year-treatment period. Thus, our results suggest that KCNQ2 GoF variants Y141N and G239S cause a mild DD with prominent language deficits in the absence of neonatal seizures and that treatment with the Kv7 channel blocker amitriptyline might represent a potential targeted treatment for patients with KCNQ2 GoF variants.

Cannabinoid hyperemesis syndrome: prevalence and management in an era of cannabis legalization.

As more states legalize cannabinoid products for recreational use and medicinal purposes, the prevalence of cannabinoid hyperemesis syndrome has become increasingly common. Yet, it remains unrecognized to many healthcare providers along with the most efficacious treatments. Cannabinoid hyperemesis syndrome most often presents with episodic vomiting secondary to chronic daily cannabis use over several months to years. Patients often complain of nausea and abdominal pain that is improved by taking hot showers or baths. Symptoms are alleviated with the cessation of cannabis use over a period of 6-12 months. Treatment for acute attacks often consists of parenteral benzodiazepines in the inpatient setting. Long-term management and prevention of further attacks are aided by tricyclic antidepressants such as amitriptyline with a dose range of 50-200 mg/d. Once a patient is in remission, amitriptyline can be tapered slowly. As cannabis becomes more widely available and accepted in the continental United States, so must education on the diagnosis of cannabinoid hyperemesis syndrome and treatment strategies.

Cost-minimization analysis of escitalopram, fluoxetine, and amitriptyline in the treatment of depression.

INTRODUCTION: Escitalopram, fluoxetine, and amitriptyline are the drugs commonly used in the treatment of depression. The pharmacoeconomic evaluation of these drugs becomes relevant as they are prescribed for a long period of time, and depression causes a significant economic burden. The cost-minimization study would contribute to bringing down the annual treatment costs, leading to better medication adherence and ultimately better patient outcomes. MATERIALS AND METHODS: All drug prices are mentioned in Indian National Rupee (INR). All expenses are based on 2022 pricing. No cost discounting was used because all expenditures were calculated over a year. We considered hypothetical scenarios where the patient was prescribed the lowest possible dose for depression, an equivalent antidepressant dose, a defined daily dose, and the maximum acceptable therapeutic dose for depression. RESULTS: Annual average treatment costs of amitriptyline, escitalopram, and fluoxetine in patients with depression at baseline with equivalent dosing as mono-drug therapy were 2765.53, 2914.78, and 1422.72 rupees (INR), respectively. Savings were high when the patient was shifted to fluoxetine from either escitalopram or amitriptyline. The savings from switching to fluoxetine were 50.66% and 56.42% from escitalopram and amitriptyline, respectively. CONCLUSION: The choice of an antidepressant depends on multiple aspects, among which the cost of treatment plays a crucial role. Among the drugs compared, fluoxetine seems to offer greater value for money. The study emphasizes that selective serotonin reuptake inhibitors are the most commonly prescribed antidepressants not only because of their favorable pharmacological profile but also because of their affordability.

The investigation of antidepressant and anxiolytic effects of pregabalin and its mechanisms of action in rats.

OBJECTIVES: Pregabalin (PGB) is used in drug-resistant epilepsy. Also, it has analgesic effects in painful syndromes. Depression and anxiety are commonly seen in epilepsy and neuropathic pain patients. PGB is often combined with anxiolytics and antidepressants. We aimed to investigate the antidepressant and anxiolytic effects of PGB and compare its effects with those of antidepressant and anxiolytic drugs and their combined use. METHODS: Wistar Albino rats were used, and PGB (5, 10, 20, and 40 mg/kg), amitriptylin (AMT), fluoxetine (FLX), ketamine (KET), and diazepam (DZM), as well as combinations of PGB (20 mg/kg) with AMT, FLX, KET, and DZM, were administered. Elevated plus maze, forced swimming, and locomotor activity tests were performed. RESULTS: In the elevated plus maze, PGB10, 20, 40, AMT, FLX, and DZM increased open arm time. The PGB20+FLX combination increased compared to PGB20. In forced swimming, PGB doses increased immobility time. AMT, FLX, DZM, and KET decreased compared to control and PGB doses. Other combinations of PGB20 reversed immobility time, except FLX. In locomotor activity, PGB20, AMT, KET, and DZM decreased distance. CONCLUSION: PGB had a depressant effect in all doses and a dose-dependently anxiolytic effect. In combinations of PGB with AMT, KET, and DZM, it reversed their antidepressant effects. We assumed FLX could be preferred instead of AMT in patients using PGB. When PGB is used in combination, drug interactions should be considered. These results are also very remarkable in terms of pharmacoeconomics.

Amitriptyline at Low-Dose and Titrated for Irritable Bowel Syndrome as Second-Line Treatment in primary care (ATLANTIS): a randomised, double-blind, placebo-controlled, phase 3 trial.

BACKGROUND: Most patients with irritable bowel syndrome (IBS) are managed in primary care. When first-line therapies for IBS are ineffective, the UK National Institute for Health and Care Excellence guideline suggests considering low- dose tricyclic antidepressants as second-line treatment, but their effectiveness in primary care is unknown, and they are infrequently prescribed in this setting. METHODS: This randomised, double-blind, placebo-controlled trial (Amitriptyline at Low-Dose and Titrated for Irritable Bowel Syndrome as Second-Line Treatment [ATLANTIS]) was conducted at 55 general practices in England. Eligible participants were aged 18 years or older, with Rome IV IBS of any subtype, and ongoing symptoms (IBS Severity Scoring System [IBS-SSS] score ≥75 points) despite dietary changes and first-line therapies, a normal full blood count and C-reactive protein, negative coeliac serology, and no evidence of suicidal ideation. Participants were randomly assigned (1:1) to low-dose oral amitriptyline (10 mg once daily) or placebo for 6 months, with dose titration over 3 weeks (up to 30 mg once daily), according to symptoms and tolerability. Participants, their general practitioners, investigators, and the analysis team were all masked to allocation throughout the trial. The primary outcome was the IBS-SSS score at 6 months. Effectiveness analyses were according to intention-to-treat; safety analyses were on all participants who took at least one dose of the trial medication. This trial is registered with the ISRCTN Registry (ISRCTN48075063) and is closed to new participants. FINDINGS: Between Oct 18, 2019, and April 11, 2022, 463 participants (mean age 48·5 years [SD 16·1], 315 [68%] female to 148 [32%] male) were randomly allocated to receive low-dose amitriptyline (232) or placebo (231). Intention-to-treat analysis of the primary outcome showed a significant difference in favour of low-dose amitriptyline in IBS-SSS score between groups at 6 months (-27·0, 95% CI -46·9 to -7·10; p=0·0079). 46 (20%) participants discontinued low-dose amitriptyline (30 [13%] due to adverse events), and 59 (26%) discontinued placebo (20 [9%] due to adverse events) before 6 months. There were five serious adverse reactions (two in the amitriptyline group and three in the placebo group), and five serious adverse events unrelated to trial medication. INTERPRETATION: To our knowledge, this is the largest trial of a tricyclic antidepressant in IBS ever conducted. Titrated low-dose amitriptyline was superior to placebo as a second-line treatment for IBS in primary care across multiple outcomes, and was safe and well tolerated. General practitioners should offer low-dose amitriptyline to patients with IBS whose symptoms do not improve with first-line therapies, with appropriate support to guide patient-led dose titration, such as the self-titration document developed for this trial. FUNDING: National Institute for Health and Care Research Health Technology Assessment Programme (grant reference 16/162/01).

Optimal pharmacotherapy pathway in adults with diabetic peripheral neuropathic pain: the OPTION-DM RCT.

BACKGROUND: The mainstay of treatment for diabetic peripheral neuropathic pain is pharmacotherapy, but the current National Institute for Health and Care Excellence guideline is not based on robust evidence, as the treatments and their combinations have not been directly compared. OBJECTIVES: To determine the most clinically beneficial, cost-effective and tolerated treatment pathway for diabetic peripheral neuropathic pain. DESIGN: A randomised crossover trial with health economic analysis. SETTING: Twenty-one secondary care centres in the UK. PARTICIPANTS: Adults with diabetic peripheral neuropathic pain with a 7-day average self-rated pain score of ≥ 4 points (Numeric Rating Scale 0-10). INTERVENTIONS: Participants were randomised to three commonly used treatment pathways: (1) amitriptyline supplemented with pregabalin, (2) duloxetine supplemented with pregabalin and (3) pregabalin supplemented with amitriptyline. Participants and research teams were blinded to treatment allocation, using over-encapsulated capsules and matching placebos. Site pharmacists were unblinded. OUTCOMES: The primary outcome was the difference in 7-day average 24-hour Numeric Rating Scale score between pathways, measured during the final week of each pathway. Secondary end points included 7-day average daily Numeric Rating Scale pain score at week 6 between monotherapies, quality of life (Short Form questionnaire-36 items), Hospital Anxiety and Depression Scale score, the proportion of patients achieving 30% and 50% pain reduction, Brief Pain Inventory - Modified Short Form items scores, Insomnia Severity Index score, Neuropathic Pain Symptom Inventory score, tolerability (scale 0-10), Patient Global Impression of Change score at week 16 and patients' preferred treatment pathway at week 50. Adverse events and serious adverse events were recorded. A within-trial cost-utility analysis was carried out to compare treatment pathways using incremental costs per quality-adjusted life-years from an NHS and social care perspective. RESULTS: A total of 140 participants were randomised from 13 UK centres, 130 of whom were included in the analyses. Pain score at week 16 was similar between the arms, with a mean difference of -0.1 points (98.3% confidence interval -0.5 to 0.3 points) for duloxetine supplemented with pregabalin compared with amitriptyline supplemented with pregabalin, a mean difference of -0.1 points (98.3% confidence interval -0.5 to 0.3 points) for pregabalin supplemented with amitriptyline compared with amitriptyline supplemented with pregabalin and a mean difference of 0.0 points (98.3% confidence interval -0.4 to 0.4 points) for pregabalin supplemented with amitriptyline compared with duloxetine supplemented with pregabalin. Results for tolerability, discontinuation and quality of life were similar. The adverse events were predictable for each drug. Combination therapy (weeks 6-16) was associated with a further reduction in Numeric Rating Scale pain score (mean 1.0 points, 98.3% confidence interval 0.6 to 1.3 points) compared with those who remained on monotherapy (mean 0.2 points, 98.3% confidence interval -0.1 to 0.5 points). The pregabalin supplemented with amitriptyline pathway had the fewest monotherapy discontinuations due to treatment-emergent adverse events and was most commonly preferred (most commonly preferred by participants: amitriptyline supplemented with pregabalin, 24%; duloxetine supplemented with pregabalin, 33%; pregabalin supplemented with amitriptyline, 43%; p = 0.26). No single pathway was superior in cost-effectiveness. The incremental gains in quality-adjusted life-years were small for each pathway comparison [amitriptyline supplemented with pregabalin compared with duloxetine supplemented with pregabalin -0.002 (95% confidence interval -0.011 to 0.007) quality-adjusted life-years, amitriptyline supplemented with pregabalin compared with pregabalin supplemented with amitriptyline -0.006 (95% confidence interval -0.002 to 0.014) quality-adjusted life-years and duloxetine supplemented with pregabalin compared with pregabalin supplemented with amitriptyline 0.007 (95% confidence interval 0.0002 to 0.015) quality-adjusted life-years] and incremental costs over 16 weeks were similar [amitriptyline supplemented with pregabalin compared with duloxetine supplemented with pregabalin -£113 (95% confidence interval -£381 to £90), amitriptyline supplemented with pregabalin compared with pregabalin supplemented with amitriptyline £155 (95% confidence interval -£37 to £625) and duloxetine supplemented with pregabalin compared with pregabalin supplemented with amitriptyline £141 (95% confidence interval -£13 to £398)]. LIMITATIONS: Although there was no placebo arm, there is strong evidence for the use of each study medication from randomised placebo-controlled trials. The addition of a placebo arm would have increased the duration of this already long and demanding trial and it was not felt to be ethically justifiable. FUTURE WORK: Future research should explore (1) variations in diabetic peripheral neuropathic pain management at the practice level, (2) how OPTION-DM (Optimal Pathway for TreatIng neurOpathic paiN in Diabetes Mellitus) trial findings can be best implemented, (3) why some patients respond to a particular drug and others do not and (4) what options there are for further treatments for those patients on combination treatment with inadequate pain relief. CONCLUSIONS: The three treatment pathways appear to give comparable patient outcomes at similar costs, suggesting that the optimal treatment may depend on patients' preference in terms of side effects. TRIAL REGISTRATION: The trial is registered as ISRCTN17545443 and EudraCT 2016-003146-89. FUNDING: This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme, and will be published in full in Health Technology Assessment; Vol. 26, No. 39. See the NIHR Journals Library website for further project information.

The number of people with diabetes is growing rapidly in the UK and is predicted to rise to over 5 million by 2025. Diabetes causes nerve damage that can lead to severe painful symptoms in the feet, legs and hands. One-quarter of all people with diabetes experience these symptoms, known as 'painful diabetic neuropathy'. Current individual medications provide only partial benefit, and in only around half of patients. The individual drugs, and their combinations, have not been compared directly against each other to see which is best. We conducted a study to see which treatment pathway would be best for patients with painful diabetic neuropathy. The study included three treatment pathways using combinations of amitriptyline, duloxetine and pregabalin. Patients received all three treatment pathways (i.e. amitriptyline treatment for 6 weeks and pregabalin added if needed for a further 10 weeks, duloxetine treatment for 6 weeks and pregabalin added if needed for a further 10 weeks and pregabalin treatment for 6 weeks and amitriptyline added if needed for a further 10 weeks); however, the order of the treatment pathways was decided at random. We compared the level of pain that participants experienced in each treatment pathway to see which worked best. On average, people said that their pain was similar after each of the three treatments and their combinations. However, two treatments in combination helped some patients with additional pain relief if they only partially responded to one. People also reported improved quality of life and sleep with the treatments, but these were similar for all the treatments. In the health economic analysis, the value for money and quality of life were similar for each pathway, and this resulted in uncertainty in the cost-effectiveness conclusions, with no one pathway being more cost-effective than the others. The treatments had different side effects, however; pregabalin appeared to make more people feel dizzy, duloxetine made more people nauseous and amitriptyline resulted in more people having a dry mouth. The pregabalin supplemented by amitriptyline pathway had the smallest number of treatment discontinuations due to side effects and may be the safest for patients.

Comparison of amitriptyline supplemented with pregabalin, pregabalin supplemented with amitriptyline, and duloxetine supplemented with pregabalin for the treatment of diabetic peripheral neuropathic pain (OPTION-DM): a multicentre, double-blind, randomised crossover trial.

BACKGROUND: Diabetic peripheral neuropathic pain (DPNP) is common and often distressing. Most guidelines recommend amitriptyline, duloxetine, pregabalin, or gabapentin as initial analgesic treatment for DPNP, but there is little comparative evidence on which one is best or whether they should be combined. We aimed to assess the efficacy and tolerability of different combinations of first-line drugs for treatment of DPNP. METHODS: OPTION-DM was a multicentre, randomised, double-blind, crossover trial in patients with DPNP with mean daily pain numerical rating scale (NRS) of 4 or higher (scale is 0-10) from 13 UK centres. Participants were randomly assigned (1:1:1:1:1:1), with a predetermined randomisation schedule stratified by site using permuted blocks of size six or 12, to receive one of six ordered sequences of the three treatment pathways: amitriptyline supplemented with pregabalin (A-P), pregabalin supplemented with amitriptyline (P-A), and duloxetine supplemented with pregabalin (D-P), each pathway lasting 16 weeks. Monotherapy was given for 6 weeks and was supplemented with the combination medication if there was suboptimal pain relief (NRS >3), reflecting current clinical practice. Both treatments were titrated towards maximum tolerated dose (75 mg per day for amitriptyline, 120 mg per day for duloxetine, and 600 mg per day for pregabalin). The primary outcome was the difference in 7-day average daily pain during the final week of each pathway. This trial is registered with ISRCTN, ISRCTN17545443. FINDINGS: Between Nov 14, 2017, and July 29, 2019, 252 patients were screened, 140 patients were randomly assigned, and 130 started a treatment pathway (with 84 completing at least two pathways) and were analysed for the primary outcome. The 7-day average NRS scores at week 16 decreased from a mean 6·6 (SD 1·5) at baseline to 3·3 (1·8) at week 16 in all three pathways. The mean difference was -0·1 (98·3% CI -0·5 to 0·3) for D-P versus A-P, -0·1 (-0·5 to 0·3) for P-A versus A-P, and 0·0 (-0·4 to 0·4) for P-A versus D-P, and thus not significant. Mean NRS reduction in patients on combination therapy was greater than in those who remained on monotherapy (1·0 [SD 1·3] vs 0·2 [1·5]). Adverse events were predictable for the monotherapies: we observed a significant increase in dizziness in the P-A pathway, nausea in the D-P pathway, and dry mouth in the A-P pathway. INTERPRETATION: To our knowledge, this was the largest and longest ever, head-to-head, crossover neuropathic pain trial. We showed that all three treatment pathways and monotherapies had similar analgesic efficacy. Combination treatment was well tolerated and led to improved pain relief in patients with suboptimal pain control with a monotherapy. FUNDING: National Institute for Health Research (NIHR) Health Technology Assessment programme.

Mapping the selection, availability, price and affordability of essential medicines for mental health conditions at a global level.

AIMS: To provide a cross-country analysis of selection, availability, prices and affordability of essential medicines for mental health conditions, aiming to identify areas for improvement. METHODS: We used the World Health Organization (WHO) online repository of national essential medicines lists (EMLs) to extract information on the inclusion of essential psychotropic medicines within each country's EML. Data on psychotropic medicine availability, price and affordability were obtained from the Health Action International global database. Additional information on country availability, prices and affordability of essential medicines for mental disorders was identified by searching, up to January 2021, PubMed/Medline, CINAHIL, Scopus and the WHO Regional Databases. We summarised and compared the indicators across lowest-price generic and originator brand medicines in the public and private sectors, and by country income groups. RESULTS: A total of 112 national EMLs were analysed, and data on psychotropic medicine availability, price and affordability were obtained from 87 surveys. While some WHO essential psychotropic medicines, such as chlorpromazine, haloperidol, amitriptyline, carbamazepine and diazepam, were selected by most national lists, irrespective of the country income level, other essential medicines, such as risperidone or clozapine, were included by most national lists in high-income countries, but only by a minority of lists in low-income countries. Up to 40% of low-income countries did not include medicines that have been in the WHO list for decades, such as long-acting fluphenazine, lithium carbonate and clomipramine. The availability of generic and originator psychotropic medicines in the public sector was below 50% for all medicines, with low-income countries showing rates lower than the overall average. Analysis of price data revealed that procurement prices were lower than patient prices in the public sector, and medicines in the private sector were associated with the highest prices. In low-income countries, the average patient price for amitriptyline and fluoxetine was three times the international unit reference price, while the average patient price for diazepam was ten times the international unit reference price. Affordability was higher in the public than the private sector, and in high-income than low-income countries. CONCLUSION: Access to medicines for mental health conditions is an ongoing challenge for health systems worldwide, and no countries can claim to be fully aligned with the general principle of providing full access to essential psychotropic medicines. Low availability and high costs are major barriers to the use of and adherence to essential psychotropic medicines, particularly in low-and middle-income countries.

An assessment of the centrally acting muscle relaxant tolperisone on driving ability and cognitive effects compared to placebo and cyclobenzaprine.

WHAT IS KNOWN AND OBJECTIVE: Tolperisone is a centrally acting muscle relaxant under development in the United States as a treatment for acute and painful symptoms of muscle spasms. The objective of this three-way, randomized, blinded, three-period crossover study was to assess the safety and cognitive effects of tolperisone compared to placebo and the widely used muscle relaxant cyclobenzaprine in healthy volunteers. METHODS: Subjects were randomized to 1 of 3 treatment arms to receive tolperisone (150 mg), cyclobenzaprine (10 mg) or placebo 3 times per day (TID) in 3 separate study periods. Subjects completed a driving test on the Cognitive Research Corporation's Driving Simulator (CRCDS Mini-Sim), a validated driving simulator, on day 1 at time to maximum plasma concentration, on day 2 before the morning dose of study drug and on day 3 at steady state following the morning dose. Subjects were assessed on various driving parameters and on a computer-administered digit-symbol substitution test (CogScreen symbol digit coding test). The driving scenario is a monotonous 100 km highway route on which subjects are instructed to maintain speed and lane position. RESULTS AND DISCUSSION: The performance of subjects who had received tolperisone was not significantly different from those who had received placebo in terms of the primary end point: standard deviation of lateral position, a measure of weaving. Subjects who had received tolperisone also performed comparably to those who had received placebo on a range of secondary measures assessing driving ability, cognition and psychomotor performance. In contrast, subjects who had received cyclobenzaprine showed significant impairment compared to placebo (P < .01) on the primary end point of standard deviation of lateral position and on the majority of the secondary end points of driving ability. Despite their markedly poorer driving performance after receiving cyclobenzaprine, few subjects reported feeling unsafe to drive on day 1 (10.3%) and day 2 (3.4%). The incidence of adverse events was similar for tolperisone (36.4%) and placebo (29.0%) and was greater for cyclobenzaprine (45.4%). WHAT IS NEW AND CONCLUSION: Subjects who received tolperisone (150 mg TID) experienced no impact on various measures of driving, self-reported sleepiness and cognition measures compared to placebo, in contrast to those who received the widely used muscle relaxant cyclobenzaprine (10 mg TID).

A green and low-cost method employing switchable hydrophilicity solvent for the simultaneous determination of antidepressants in human urine by gas chromatography - mass spectrometry detection.

In this study, the use of switchable hydrophilicity solvent with a simple and low-cost lab-made device for the extraction procedure in homogeneous liquid-liquid microextraction is proposed for the first time in the determination of antidepressants in human urine. The antidepressants studied consisted of fluoxetine, amitriptyline, nortriptyline, imipramine, desipramine and sertraline. The optimization of the main parameters that can influence on the extraction efficiency was performed through multivariate approaches. The analytes were separated and identified by gas chromatography coupled to mass spectrometry (GC-MS). The optimal extraction conditions consisted of using N,N-dimethylcyclohexylamine (DMCHA) as the switchable hydrophilicity solvent (SHS), 500 µL of urine sample previously diluted with ultrapure water at 1:1 ratio (v/v), 200 µL of a mixture of SHS:HCl 6 mol L-1 (1:1 v/v), 600 µL of NaOH 10 mol L-1 and 3 min of extraction time. A volume of 40 µL of diphenylamine at concentration of 500 µg L-1 (20 ng) was used as internal standard. The method developed was in-house validated, providing coefficients of determination higher than 0.995 for all analytes, limits of detection (LOD) from 0.02 to 0.88 µg L-1, limits of quantification (LOQ) from 0.05 to 2.92 µg L-1, relative recoveries of 68 to 102%, intra-day precision from 0.5 to 15.9%, inter-day precision from 4.2 to 19.3%, selectivity and robustness. The method proposed was successfully applied in five human urine samples from a Toxicological Information Center located in Porto Alegre (Brazil). The results demonstrated that the µP-SHS-HLLME approach is highly cost-effective, rapid, simple and environmentally-friendly with satisfactory analytical performance.

Some t-tests for N-of-1 trials with serial correlation.

N-of-1 trials allow inference between two treatments given to a single individual. Most often, clinical investigators analyze an individual's N-of-1 trial data with usual t-tests or simple nonparametric methods. These simple methods do not account for serial correlation in repeated observations coming from the individual. Existing methods accounting for serial correlation require simulation, multiple N-of-1 trials, or both. Here, we develop t-tests that account for serial correlation in a single individual. The development includes effect size and precision calculations, both of which are useful for study planning. We then use Monte Carlo simulation to evaluate statistical properties of these serial t-tests, namely, Type I and II errors, and confidence interval widths, and compare these statistical properties to those of analogous usual t-test. The serial t-tests clearly outperform the usual t-tests commonly used in reporting N-of-1 results. Examples from N-of-1 clinical trials in fibromyalgia patients and from a behavioral health setting exhibit how accounting for serial correlation can change inferences. These t-tests are easily implemented and more appropriate than simple methods commonly used; however, caution is needed when analyzing only a few observations.

The Economic Burden of Pediatric Postconcussive Syndrome.

OBJECTIVE: To estimate the direct costs of pediatric postconcussive syndrome (PCS). DESIGN: Retrospective cohort study. SETTING: Subspecialty sports medicine clinics of a large pediatric tertiary care network in the United States. PATIENTS: One hundred fifty-four patients aged 5 to 18 years with PCS, evaluated between 2010 and 2011. ASSESSMENT OF INDEPENDENT VARIABLES: Direct costs included visits to sports medicine clinic, visio-vestibular therapy, homebound education, subspecialist referral, and prescription-only medications (amantadine and amitriptyline), all measured beginning at 28 days after injury. MAIN OUTCOME MEASURES: Postconcussive syndrome was defined as persistence beyond 28 days from injury. RESULTS: The cost incurred by each PCS patient for sports medicine visits was $1575, for visio-vestibular therapy was $985, for homebound tutoring was $55, for prescription medications was $22, and for subspecialist referral was $120, totaling $3557 per patient, with a 95% confidence interval range of $2886 to $4257. CONCLUSIONS: Given the high economic costs of PCS determined in this study, therapies that mitigate this syndrome may have the potential to be cost-effective and even cost saving.

Childhood Drug and Non-Drug Poisoning in Nigeria: An Economic Appraisal.

BACKGROUND: The dearth of information on the economic cost of childhood poisoning in sub-Saharan Africa necessitated this study. OBJECTIVE: This study has investigated the prevalence of childhood drug and non-drug poisoning, treatment modalities and economic costs in Nigeria. METHOD: A retrospective study of childhood drug and non-drug poisoning cases from January 2007 to June 2014 in the University of Port Harcourt Teaching Hospital (UPTH), Port Harcourt, Nigeria was carried out. Medical records were analysed for demographic and aetiological characteristics of poisoned children (0-14 years of age), as well as fiscal impact of poisoning cases. FINDINGS: Of the 100 poisoned patients, 46% were male and 54% female, with female/male ratio of 1.17:1. Most of the children were under five years of age. Paracetamol, amitriptyline, chlorpromazine, ferrous sulphate, kerosene, organophosphates, carbon monoxide, snake bite, alcohol and rodenticides were involved in the poisoning. The average cost of poison management per patient was about $168, which is high given the economic status of Nigeria. CONCLUSION: Childhood poisoning is still a significant cause of morbidity among children in Nigeria and accounts for an appreciable amount of health spending, therefore preventive strategies should be considered.

Quality by Design oriented development of hydrophilic interaction liquid chromatography method for the analysis of amitriptyline and its impurities.

This paper presents integration of Quality by Design concept in the development of hydrophilic interactions liquid chromatographic methods for analysis of amitriptyline and its impurities (A, B, C, and F). This is the first time that HILIC method for amitriptyline and its impurities is developed. Using QbD concept, it is possible to design a robust method and incorporate quality directly into its development. QbD concept in combination of Design of Experiments methodology (DoE) enables creation of well-defined design space. In this study, for method optimization a Box-Behnken design was used to test the effect of acetonitrile content, buffer concentration and pH of water phase on critical system responses such as retention factor of impurity A, resolution between impurity B and impurity C, amitriptyline peak asymmetry factor and retention time of last eluted impurity F. The defined mathematical models and Monte Carlo simulations were used to identify the design space. For robustness testing, fractional factorial design was applied. Optimal chromatographic conditions were the analytical column ZORBAX NH2 (250 mm x 4.6 mm, 5 µm particle size); mobile phase consisted of acetonitrile-water phase (60 mM ammonium acetate, pH adjusted to 4.5 with glacial acetic acid) (92.5:7.5 v/v); column temperature 30 °C, mobile phase flow rate 1 mL min-1, wavelength of detection 254 nm. Finally, method was fully validated and applicability of the method in tablet analysis was confirmed.

In-vitro and in situ assessment of the efflux of five antidepressants by breast cancer resistance protein.

OBJECTIVES: Antidepressants need to penetrate the blood-brain barrier (BBB) to exert their functions in the central nervous system. Breast cancer resistance protein (BCRP), an efflux transporter abundantly expressed in the BBB, prevents the accumulation of many drugs in the brain. This study aimed to identify whether five commonly used antidepressants (sertraline, duloxetine, fluoxetine, amitriptyline and mirtazapine) are BCRP substrates. METHODS: A combination of bidirectional transport and intracellular accumulation experiments was conducted on BCRP-overexpressing MDCKII and wild-type (WT) cells, and in situ brain perfusion was conducted in rats. KEY FINDINGS: The bidirectional transport study revealed that the net efflux ratio (NER) of sertraline reached 2.08 but decreased to 1.06 when co-incubated with Ko143, a selective BCRP inhibitor. Conversely, the other four antidepressants did not appear to be BCRP substrates, due to their low NER values (<1.5). The accumulation of sertraline in MDCKII-BCRP cells was significantly lower than that in MDCKII-WT cells. The presence of Ko143 significantly increased the sertraline accumulation in MDCKII-BCRP cells but not in MDCKII-WT cells. Brain perfusion showed that the permeability of 1 and 5 µm sertraline was significantly higher in the presence of Ko143. CONCLUSIONS: Taken together, BCRP is involved in sertraline efflux.

Stability Assessment of Topical Amitriptyline Extemporaneously Compounded with Lipoderm Base, PLO Gel Mediflo 30, and Emollient Cream.

Extemporaneous topical compounds for neuropathic pain offers an alternative or adjunct approach to existing therapies for patients. Assigning evidence-based beyond-use dating prior to dispensing topical medications is a legal requirement by pharmacy governing bodies. The purpose of this study was to utilize a validated stability-indicating high-performance liquid chromatography assay to determine beyond-use dating of topical amitriptyline in three different bases (Lipoderm Base, PLO Gel Mediflo 30, Emollient Cream) at three different temperatures [room temperature (25°C), refrigeration (4°C), and high temperature (40°C)]. Amitriptyline was stable after 90 days at room temperature in both Lipoderm Base and PLO Gel Mediflo 30. However, it was not stable at 40°C in Emollient Cream, irrespective of storage conditions.

Variables Associated With the Use of Prophylactic Amitriptyline Treatment in Patients With Tension-type Headache.

OBJECTIVE: The objective of this study was to investigate differences in clinical, psychological, and psychophysical outcomes according to use of prophylactic medication (amitriptyline) in tension-type headache (TTH). METHODS: In total, 173 individuals with TTH participated. Headache features and symptomatic medication intake were collected with a 4-weeks headache diary at baseline and at 6-months. Burden of headache (Headache Disability Inventory-HDI), sleep quality (Pittsburgh Sleep Quality Index-PSQI), anxiety/depression (Hospital Anxiety and Depression Scale-HADS), and trait/state anxiety levels (State-Trait Anxiety Inventory-STAI) were also assessed at baseline. Pressure pain thresholds (PPT) were assessed over the temporalis, C5-C6 joint, second metacarpal, and tibialis anterior at baseline. Differences between participants taking or not taking prophylactic medication based on self-perceived effectiveness of the medication on headache characteristics were assessed. RESULTS: In total, 49 (28%) reported taking prophylactic medication for the headaches (amitriptyline: 100%). From these, 11 (23%) reported no effect, 25 (51%) reported moderate effect, and 13 (26%) reported positive effect with medication. Patients taking prophylactic medication had longer headache history, higher frequency of headaches (61% CTTH), higher headache burden, worse quality of sleep, and higher depression than those not taking medication. Prophylactic medication was less effective in patients with generalized pressure pain hyperalgesia. No other significant differences were found. CONCLUSIONS: Prophylactic medication is used by TTH patients with higher headache frequency, higher headache burden, worse sleep quality, and higher depression. Lower effectiveness of prophylactic amitriptyline was associated with widespread pain hyperalgesia.

Assessment of adverse events in clinical drug trials: Identifying amitriptyline's placebo- and baseline-controlled side effects.

Adverse events in clinical drug trials are often poorly assessed and reported. The absence of baseline assessment and structured symptom lists, as well as the fact that most drug trials are industry-sponsored are common sources of bias. In addition, adverse events are usually assessed in patient samples, which can bias results because of the misattribution of symptoms that are part of the illness to medication intake. We aimed to identify amitriptyline's placebo- and baseline-controlled side effects by examining a sample of healthy adults, using structured assessments via a symptom list. Forty healthy individuals were randomized equally to either a group taking 50 mg amitriptyline on four consecutive days or to a placebo control group. Complaints were assessed via the Generic Assessment of Side Effects Scale prior to and after four days of medication intake. Frequency of complaints and their intensity were compared after medication intake between the two groups while controlling for complaints at baseline. The amitriptyline group's participants reported having suffered from "dry mouth," "dizziness," "subjective blood circulation-associated problems," and "constipation" significantly more often. When taking into account the complaint's intensity, the amitriptyline group also reported higher intensities for "dry mouth," "dizziness," and "subjective blood circulation-associated problems." Our results emphasize the importance of a structured and well-controlled harm assessment. Future drug trials should report the placebo- and baseline-controlled side effects with a clear causal relationship to the intake of the drug under investigation, in addition to the frequency of complaints and their odds ratios. (PsycINFO Database Record

Trends and Patterns of Antidepressant Use in French Children and Adolescents From 2009 to 2016: A Population-Based Study in the French Health Insurance Database.

PURPOSE/BACKGROUND: Over the last decade, the use of antidepressants (ATDs) in children and adolescents has markedly increased in several occidental countries, but recent data in French children are missing. This study aimed to assess trends of ATD use in French children (6-11 years) and adolescents (12-17 years) and to characterize changes in ATD prescribing patterns from 2009 to 2016. METHODS: Using data from the French Health Insurance Database, annual prevalence and incidence of ATD use and changes in ATD prescribing patterns were analyzed. RESULTS: Overall ATD prevalence of use rose slightly from 0.51% in 2009 to 0.53% in 2016 (+3.9%), with a decrease in children (0.18%-0.11%; -38.9%) and an increase in adolescents (0.86%-0.98%; +14.0%) and an overall female preponderance (56.7% in 2009; 58.7% in 2016). Serotonin reuptake inhibitor prevalence of use increased from 0.24% to 0.34%, whereas tricyclic ATD use decreased (from 0.20% to 0.16%). Similar trends were obtained with overall incidence of use, from 0.39% in 2009 to 0.36% in 2016 (-7.7%). Sertraline was the most frequently prescribed in adolescents (2009: 22.2% of all ATD prescriptions; 2016: 32.9%), whereas amitriptyline was the most prescribed in children (2009: 42.7% and 2016: 41.2%). Off-label use decreased in adolescents (from 48.4% to 34.8%) but increased in children (from 10.0% to 26.5%). IMPLICATIONS/CONCLUSIONS: Antidepressant level of use in French children and adolescents was stable in recent years and lower than that observed in other European countries and the United States.