Attention deficit hyperactivity disorder (ADHD) is a commonly diagnosed neuropsychiatric disorder in childhood and adolescence. Worldwide about 30–50% of children diagnosed in childhood with ADHD continue to have symptoms into adulthood. In contrast to North America, ADHD is identified as hyperkinetic disorder (HKM) in most European countries and is therefore used also in this dissertation. Regardless of the differences in diagnostic criteria, the same medicines are used to treat ADHD and HKM. ADHD worldwide prevalence in the children and adolescents is 8–10% and in adults 2.5–4%. The exact cause of ADHD is not known, however its burden has a high impact on the healthcare system and the community. The number of people diagnosed with ADHD is increasing worldwide. In recent years, ADHD has been diagnosed and treated more frequently in Slovenia, primarily due to better recognition and more attention to the disorder. Despite its relevance in terms of public health, the epidemiology and ADHD medicine consumption of this disorder are not well established in many Central and Eastern European countries, including Slovenia. According to the European and American guidelines, the management of ADHD consists of nonpharmacological options, and pharmacotherapy, including stimulants and nonstimulants. Atomoxetine (ATX) and methylphenidate (MPH) in different forms have been approved for treatment of children and adolescents with ADHD in Slovenia, throughout Europe, and in many other countries. In addition, ADHD is also treated with bupropion (BUP), tricyclic antidepressants and some other drugs. ADHD treatment can be a lifelong one. Medications used to treat ADHD are well researched, but there is a lack of head-to-head comparative effectiveness trials between BUP and other drugs. The aim of this work was to estimate the Slovenian parameters of ADHD epidemiology and ADHD medicine consumption in comparison with the results of other countries, and to estimate the comparative effectiveness and acceptability of AHDH drugs using a meta-analysis. The first part of this research was a review of different databases to identify articles, which have investigated the pharmacotherapy guidelines for AHDH patients with general data of the ADHD epidemiology and comparative efficacy and safety of AHDH medicines. In this part, the pharmacotherapy for AHDH patients was highlighted. ATX, immediate-release MPH, and extended release MPH are approved to be used in children and adolescents with ADHD in Slovenia. According to the pharmacotherapy guidelines the drug of choice is MPH. Consideration of the pharmacokinetic parameters of the selected medicines and potential drug-drug interactions, if the patient is taking other medications, helps to reduce ADHD symptoms and to select the appropriate medicine and medicine dosing regimen. Clinical outcomes could be measured by standardized questionnaires, which are widely available. Adults are treated with the same medicines as children and adolescents, often with maximum approved doses, which also demonstrated to be safe and effective in treating children and adolescents. ATX is the only approved drug in Slovenia for the treatment of adult ADHD patients. The review article based on this review was published in the Slovenian Medical Journal (Zdravniški vestnik). The Slovenian incidence and prevalence of ADHD diagnosis in children and adolescents have not yet been reported in the literature, therefore several epidemiological models to calculate them were built. Since the epidemiological data on the prevalence of ADHD in Slovenia do not exist, our results were compared Slovenia with Western countries. The data from the National Institute of Public Health of the Republic of Slovenia for the years 1997–2012 were analyzed. In 1997, the annual incidence rate of ADHD diagnosis in Slovenia was 0.0317% and increased to 0.0469% in 2000 and to 0.0823% in 2012. The prevalence rate of ADHD diagnosis was estimated between 722 and 767 per 100,000 children and adolescents. If the increase persists, the prevalence of ADHD diagnosis in Slovenia in 2020 will be 6.3-fold higher than in 1997 and 1.3-fold higher than in 2012. There were some regional differences in the epidemiology of ADHD in Slovenia, but interregional comparison is not viable because of the low incidence of ADHD, better traffic connections, the small country size, and different levels of access to specialists. These epidemiological models could be widely applicable, especially in this part of Europe, where a registry of AHDH patients is not available. Almost identical results were calculated with all models. From these results, it can be concluded that ADHD in Slovenia is common, but it is still underdiagnosed in comparison with Western countries. Results also indicated a need for improved timely interventions in Slovenia, not only in child and adolescent psychiatry but also in primary settings and adult psychiatry, where ADHD should be recognized efficiently. The article based on this research was submitted in to the Croatian Medical Journal. The second part of research was in the field of drug consumption. The main aim was to present the pattern and the evolution of national ADHD drug consumption in Slovenia. For this purpose, the national consumption outpatient data for the period 2001–2012 and medication costs were obtained from the database of the Health Insurance Institute of Slovenia. Total medicine consumption per 1000 inhabitants per day and the total medication cost in euros were extracted. Only immediate-release methylphenidate (IR-MPH), methylphenidate-osmotic release oral delivery system (OROS-MPH) and atomoxetine (ATX) have been approved for ADHD in Slovenia and are included in this study. The amphetamines had not been available in Slovenia and were excluded from this study. ADHD medicine consumption increased in Slovenia from 0.0537 defined daily dose (DDD)/1000 inhabitants/day in 2001, to 0.0687 DDD/1000 inhabitants/day in 2006 and 0.3076 DDD/1000 inhabitants/day in 2012. The rise was largely due to an increase in OROS-MPH and ATX consumption, while the consumption of IR-MPH decreased rapidly. In the study period, the total cost of the medicines increased 31-fold. The total cost of ADHD medicines increased 14-fold during 2007–2010, and by only 11.4% during 2010–2012. The prescribed amounts of medicines for ADHD are the highest in the regions of Koper and Novo mesto and the lowest in the regions of Murska Sobota and Nova Gorica. There were regional differences in the ATX prescribing trend, for example, in Novo mesto and Krško. Inappropriate prescribing can be associated with noncompliance with European treatment guidelines and the impact of pharmaceutical marketing in favor of prescribing ATX in these regions. The changes in the pattern of prescribing medicine are evident in Slovenia, primarily in the increase of OROS-MPH and ATX consumption and in the rapid decrease of IR-MPH consumption. The article based on this research was accepted for publication in Journal of Child and Adolescent Psychopharmacology. The third part of this research was a comparison of ADHD medicines by their efficacy and acceptability. Individual ADHD medications have been well researched until now, but there is a lack of comparative effectiveness research among medications in terms of efficacy and acceptability, where BUP is compared with ATX, lisdexamfetamine (LDX)and MPH. Consequently, a meta-analysis, comparing the efficacy and acceptability of MPH, LDX, BUP and ATX for treating ADHD symptoms in children and adolescents was performed. A literature search was conducted to identify double-blind, placebo-controlled, noncrossover studies of ADHD in youth published after 1950. PubMed/Medline and Clinicaltrials.gov were searched using the key words "attention deficit hyperactivity disorder" or "ADHD" and "drug". All-cause treatment discontinuation and treatment score were the primary endpoints. Drug acceptability was calculated based on the odds ratio (OR), while efficacy was calculated based on the standardized mean difference (SMD). The absolute effect sizes versus placebo expressed in SMD were: BUP -0.32 (95% CI, -0.69, 0.05) showed small efficacy, ATX -0.68 (95% CI, -0.76, -0.59) and MPH -0.75 (95% CI, -0.98, -0.52) showed modest efficacy in reducing ADHD symptoms and LDX showed high efficacy -1.28 (95% CL, -1.84, -0.71). Treatment discontinuations were lower than with a placebo, nonsignificant for ATX (OR = 0.91; 95% CI, 0.66, 1.24) and LDX (OR = 0.60; 95% CI, 0.22, 1.65) and significantly higher (OR = 0.35; 95% CI, 0.24, 0.52) and nonsignificantly higher for BUP (OR = 1.64; 95% CI, 0.5, 5.43). The results suggest that LDX has the best benefit-risk balance and has promising potential for treating children and adolescents with ADHD. This meta-analysis is the third to compare BUP with LDX by their efficiacy and the second to further compare BUP with LDX. It is also the first nonsponsored meta-analysis that analyzes and reports on discontinuations of ATX, BUP, LDX and MPH. The article based on this research was submitted in to the Journal of Affective Disorders. In the last part, a case report of a 17-year old Slovenian ADHD adolescent treated with ATX, who was previously treated with clozapine and levomepromazine and other medicines was reported. The case was described to identify diagnostic and treatment gaps resulting in prolonged hospitalization. ATX was introduced after 7 years of treatment with several medicines. The introduction of ATX (60 mg daily) resulted in a gradual improvement of ADHD symptoms. After 2 months of treatment with ATX, palpitations and loss of consciousness were reported, along with an increased heart rate (115 bpm), sinus arrhythmia and a prolonged QT (QTc = 540 ms) interval. The therapy with ATX was abruptly discontinued and the patient recovered. ATX should be included among the causes of drug-induced cardiovascular adverse effects. The patient was treated in a psychiatric hospital for adults, which suggests a lack of services for the treatment of ADHD in Slovenia. The article in the Letter to the editor form based on this case study was published in the Irish Medical Journal and presented on the 4th World Congress on ADHD, From Childhood to Adult Disease 06–09 June 2013, Milan, Italy. These findings in the field of ADHD contribute new data on the epidemiology, ADHD medicine consumption and comparative efficacy and acceptability of ADHD drugs. Further investigation of ADHD in Slovenia and in Europe is suggested.
|