Digital Care Pathway for Patients With Sleep Apnea in Specialized Care: Mixed Methods Study

BACKGROUND

Sleep apnea is a significant public health disorder in Finland, with a prevalence of 3.7%. Continuous positive airway pressure (CPAP) therapy is the first-line treatment for moderate or severe sleep apnea. From November 18, 2019, all patients who started their CPAP therapy at Oulu University Hospital were attached to a sleep apnea digital care pathway (SA-DCP) and were instructed on its use. Some patients still did not use the SA-DCP although they had started their CPAP therapy.

OBJECTIVE

We aimed to study health care professionals' (HCPs') perspectives on the SA-DCP and its usefulness for their work; whether the main targets of SA-DCP can be reached: shortening the initial guiding sessions of CPAP therapy, reducing patient calls and contact with HCPs, and improving patients' adherence to CPAP therapy; and patients' perspectives on the SA-DCP and its usefulness to them.

METHODS

Overall, 6 HCPs were interviewed in May and June 2021. The survey for SA-DCP users (58/91, 64%) and SA-DCP nonusers (33/91, 36%) was conducted in 2 phases: from May to August 2021 and January to June 2022. CPAP device remote monitoring data were collected from SA-DCP users (80/170, 47.1%) and SA-DCP nonusers (90/170, 52.9%) in May 2021. The registered phone call data were collected during 2019, 2020, and 2021. Feedback on the SA-DCP was collected from 446 patients between February and March 2022.

RESULTS

According to HCPs, introducing the SA-DCP had not yet significantly improved their workload and work practices, but it had brought more flexibility in some communication situations. A larger proportion of SA-DCP users familiarized themselves with prior information about CPAP therapy before the initial guiding session than nonusers (43/58, 74% vs 16/33, 49%; P=.02). Some patients still had not received prior information about CPAP therapy; therefore, most of the sessions were carried out according to their needs. According to the patient survey and remote monitoring data of CPAP devices, adherence to CPAP therapy was high for both SA-DCP users and nonusers. The number of patients' phone calls to HCPs did not decrease during the study. SA-DCP users perceived their abilities to use information and communications technology to be better than nonusers (mean 4.2, SD 0.8 vs mean 3.2, SD 1.2; P<.001).

CONCLUSIONS

According to this study, not all the goals set for the introduction of the SA-DCP have been achieved. Despite using the SA-DCP, some patients still wanted to communicate with HCPs by phone. The most significant factors explaining the nonuse of the SA-DCP were lower digital literacy and older age of the patients. In the future, more attention should be paid to these user groups when designing and introducing upcoming digital care pathways.

Reporting of costs and economic impacts in randomized trials of de-implementation interventions for low-value care: a systematic scoping review

BACKGROUND

De-implementation of low-value care can increase health care sustainability. We evaluated the reporting of direct costs of de-implementation and subsequent change (increase or decrease) in health care costs in randomized trials of de-implementation research.

METHODS

We searched MEDLINE and Scopus databases without any language restrictions up to May 2021. We conducted study screening and data extraction independently and in duplicate. We extracted information related to study characteristics, types and characteristics of interventions, de-implementation costs, and impacts on health care costs. We assessed risk of bias using a modified Cochrane risk-of-bias tool.

RESULTS

We screened 10,733 articles, with 227 studies meeting the inclusion criteria, of which 50 included information on direct cost of de-implementation or impact of de-implementation on health care costs. Studies were mostly conducted in North America (36%) or Europe (32%) and in the primary care context (70%). The most common practice of interest was reduction in the use of antibiotics or other medications (74%). Most studies used education strategies (meetings, materials) (64%). Studies used either a single strategy (52%) or were multifaceted (48%). Of the 227 eligible studies, 18 (8%) reported on direct costs of the used de-implementation strategy; of which, 13 reported total costs, and 12 reported per unit costs (7 reported both). The costs of de-implementation strategies varied considerably. Of the 227 eligible studies, 43 (19%) reported on impact of de-implementation on health care costs. Health care costs decreased in 27 studies (63%), increased in 2 (5%), and were unchanged in 14 (33%).

CONCLUSION

De-implementation randomized controlled trials typically did not report direct costs of the de-implementation strategies (92%) or the impacts of de-implementation on health care costs (81%). Lack of cost information may limit the value of de-implementation trials to decision-makers.

TRIAL REGISTRATION

OSF (Open Science Framework): https://osf.io/ueq32 .

Characteristics and predictors of off-label use of antipsychotics in general population sample

OBJECTIVE

Increasing number of people have been prescribed antipsychotics (APs) off-label in recent decades. This study aimed to identify the characteristics and predictors of receiving prescription of antipsychotics off-label.

METHODS

The study sample was part of the Northern Finland Birth Cohort 1966 (n = 7071). Data included questionnaires and national register data. Information on prescribed medications was extracted from the national register. The sample was divided into three groups: Persons who had been prescribed APs off-label (n = 137), individuals with non-psychotic mental disorders without APs off label (n = 1478) and individuals who had been diagnosed with psychosis or bipolar disorder and who had been prescribed APs (n = 151). We compared sociodemographic, lifestyle and clinical characteristics between the off-label and the comparison groups using logistic regression.

RESULTS

The most common diagnoses in the off-label group were depression (n = 96, 70.1%) and anxiety (n = 55, 40.1%). Compared with individuals with non-psychotic mental disorders who were not prescribed APs off-label, individuals with prescribed off-label APs had a lower level of education, lower socioeconomic status, were less often married, had a higher level of somatic and psychiatric morbidity, were more often smokers and more often had a substance abuse disorder and heavy alcohol consumption. When comparing the off-label group to individuals with psychosis or bipolar disorder who used APs, there were less differences, though individuals with psychosis or bipolar disorder had more markers of morbidity and a lower level of education.

CONCLUSION

Individuals who had been prescribed APs off label had a higher level of mental and somatic morbidity and poorer socioeconomic status than individuals with non-psychotic mental disorders who did not use APs.

Detecting Patient Safety Errors by Characterizing Incidents Reported by Medical Imaging Staff

The objectives of the study were to characterize events related to patient safety reported by medical imaging personnel in Finland in 2007–2017, the number and quality of reported injuries, the risk assessment, and the planned improvement of operations. The information was collected from a healthcare patient safety incident register system. The data contained information on the nature of the patient safety errors, harms and near-misses in medical imaging, the factors that lead to the events, the consequences for the patient, the level of risks, and future measures. The number of patient safety incident reports included in the study was 7,287. Of the incident reports, 75% concerned injuries to patients and 25% were near-misses. The most common consequence of adverse events and near-misses were minor harm (37.2%) related to contrast agent, or no harm (27.9%) related to equipment malfunction. Supervisors estimated the risks as low (47.7%) e.g., data management, insignificant (35%) e.g., verbal communication or moderate (15.7%) e.g., the use of contrast agent. The most common suggestion for learning from the incident was discussing it with the staff (58.1%), improving operations (5.7%) and submitting it to a higher authority (5.4%). Improving patient safety requires timely, accurate and clear reporting of various patient safety incidents. Based on incident reports, supervisors can provide feedback to staff, develop plans to prevent accidents, and monitor the impact of measures taken. Information on the development of occupational safety should be disseminated to all healthcare professionals so that the same mistakes are not repeated.

Medication-related adverse events in health care-what have we learned? A narrative overview of the current knowledge

Purpose

Although medication-related adverse events (MRAEs) in health care are vastly studied, high heterogeneity in study results complicates the interpretations of the current situation. The main objective of this study was to form an up-to-date overview of the current knowledge of the prevalence, risk factors, and surveillance of MRAEs in health care.

Methods

Electronic databases (PubMed, MEDLINE, Web of Science, and Scopus) were searched with applicable search terms to collect information on medication-related adverse events. In order to obtain an up-to-date view of MRAEs, only studies published after 2000 were accepted.

Results

The prevalence rates of different MRAEs vary greatly between individual studies and meta-analyses. Study setting, patient population, and detection methods play an important role in determining detection rates, which should be regarded while interpreting the results. Medication-related adverse events are more common in elderly patients and patients with lowered liver or kidney function, polypharmacy, and a large number of additional comorbidities. However, the risk of MRAEs is also significantly increased by the use of high-risk medicines but also in certain care situations. Preventing MRAEs is important as it will decrease patient mortality and morbidity but also reduce costs and functional challenges related to them.

Conclusions

Medication-related adverse events are highly common and have both immediate and long-term effects to patients and healthcare systems worldwide. Conclusive solutions for prevention of all medication-related harm are impossible to create. In the future, however, the development of efficient real-time detection methods can provide significant improvements for event prevention and forecasting.

Investigating errors in medical imaging: medical malpractice cases in Finland

Objective

The objectives of the study were to survey patient injury claims concerning medical imaging in Finland in 1991–2017, and to investigate the nature of the incidents, the number of claims, the reasons for the claims, and the decisions made concerning the claims.

Materials and methods

The research material consisted of patient claims concerning imaging, sent to the Finnish Patient Insurance Centre (PVK). The data contained information on injury dates, the examination code, the decision code, the description of the injury, and the medical grounds for decisions.

Results

The number of claims included in the study was 1054, and the average number per year was 87. The most common cause was delayed diagnosis (404 claims, 38.3%). Most of the claims concerned mammography (314, 29.8%), radiography (170, 16.1%), and MRI (162, 15.4%). According to the decisions made by the PVK, there were no delays in 54.6% of the examinations for which claims were made. About 30% of all patient claims received compensation, the most typical reason being medical malpractice (27.7%), followed by excessive injuries and injuries caused by infections, accidents and equipment (2.7%).

Conclusion

Patient injury in imaging examinations and interventions cannot be completely prevented. However, injury data are an important source of information for health care. By analysing claims, we can prevent harm, increase the quality of care, and improve patient safety in medical imaging.

Inhibition and induction of CYP enzymes in humans: an update

The cytochrome P450 (CYP) enzyme family is the most important enzyme system catalyzing the phase 1 metabolism of pharmaceuticals and other xenobiotics such as herbal remedies and toxic compounds in the environment. The inhibition and induction of CYPs are major mechanisms causing pharmacokinetic drug–drug interactions. This review presents a comprehensive update on the inhibitors and inducers of the specific CYP enzymes in humans. The focus is on the more recent human in vitro and in vivo findings since the publication of our previous review on this topic in 2008. In addition to the general presentation of inhibitory drugs and inducers of human CYP enzymes by drugs, herbal remedies, and toxic compounds, an in-depth view on tyrosine-kinase inhibitors and antiretroviral HIV medications as victims and perpetrators of drug–drug interactions is provided as examples of the current trends in the field. Also, a concise overview of the mechanisms of CYP induction is presented to aid the understanding of the induction phenomena.

The Risks and Outcomes Resulting From Medication Errors Reported in the Finnish Tertiary Care Units:: A Cross-Sectional Retrospective Register Study

Background: Hospital-acquired medication errors (MEs) are common in health care. Although voluntary reporting is criticized for not producing reliable estimates on ME frequency, it provides valuable knowledge on errors occurring in the medication process. Objective: The purpose of this study was to analyze and determine the risks and outcomes resulting from MEs related to the TOP15 medicines in the Finnish tertiary care units from July 2016 to July 2017. Methods: The data consisting of 1,447 ME reports was organized according to ATC classification, after which TOP15 medicines involved in the reports were selected. Inductive content analysis was performed to the reports. After this, the reports were categorized by ME outcome into five categories and further analyzed accordingly. Results: The most common ME outcome in the reports was "omitted medicine" (33.9%). More than a quarter (27.1%) of ME reports were estimated to cause moderate or severe risk to the patient. When compared with each other, none of the outcome groups were more susceptible to high-risk events (p = 0.71). Of the TOP15 medicines, only Norepinephrine had significantly higher risk of being involved in high-risk events (OR 2.43, 95%CI 1.35-4.61). Conclusion: Voluntary reporting has an important role in the development of medication safety and the overall medication process within organizations. Although majority of the TOP15 medicines were involved in MEs resulting in seemingly high-risk outcomes, they were estimated to be insignificant or minor within the reporting unit. In the future, more emphasis will be needed for the assessment and analysis of the reports for more efficient, real-time detection and response to signals from health care units.

The prevalence of medication-related adverse events in inpatients-a systematic review and meta-analysis

PURPOSE

Adverse drug events (ADEs) have been internationally recognized as a major threat to patient safety. The purpose of this study was to conduct a meta-analysis focusing on inpatient ADEs in the Western World to provide better estimate of the current state of medication safety in these countries.

METHODS

The studies for meta-analysis were identified through electronic search in Cochrane, Scopus, Medline, and Web of science databases. Included articles focused on adult inpatient ADEs, had commonly accepted definition for ADE, and were conducted between 2000 and 2016. Disease or ADE-specific studies were excluded. Meta-analysis was conducted on the prevalence of inpatient ADEs and fatal adverse drug reactions (FADRs).

RESULTS

The pooled estimate of the prevalence of inpatient ADEs was formed by 46,626 patient records included in 9 articles. Inpatient ADE prevalence was 19 and 32.3% of these ADEs were assessed preventable (MD 28.6%, SD 22.6%). Three articles including 3385 patients focused on inpatient FADRs, but the pooled estimate of this was disregarded due to low number and high heterogeneity of the included studies.

CONCLUSIONS

ADEs are estimated to affect 19% of inpatients during hospitalization. Most of the ADEs are moderate in severity causing no permanent harm to the patient. Only a small amount of ADEs cause inpatient deaths, but in this meta-analysis, however, we were unable to give direct estimate of the prevalence.

New study designs in clinical drug development

Clinical development of a novel drug has traditionally been seen as a series of four phases, each having its own objectives in establishing the efficacy and safety of the drug. Increasingly individualized medicine and the changing mechanisms of drug action are also changing the designs of clinical drug testing. The borders of development phases become blurred and the traditional large, controlled multicenter studies may in part be replaced by individual and risk-based approaches. The indications for drugs are more precisely targeted from biological starting points, and a target-oriented development may guide the designs of clinical testing at all stages of development. Utilization of data from registries along with modeling will become more common in clinical drug testing.

Metabolism and metabolite profiles in vitro and in vivo of ospemifene in humans and preclinical species

BACKGROUND

Metabolite profiles of ospemifene, a novel nonsteroidal selective estrogen receptor modulator, were surveyed as part of its development.

METHODS

The pharmacokinetics of ospemifene and its two major, pharmacologically active metabolites 4-hydroxyospemifene and 4'-hydroxyospemifene, was elucidated in studies of volunteer humans given various doses of ospemifene and in experiments of several animal species (rat, mouse, dog, and cynomolgus monkey), which had been used either for pharmacological or toxicological studies of ospemifene. Metabolites produced in in vitro human and animal liver preparations were compared between species and with the metabolite profiles in the in vivo investigations.

RESULTS

Considerable interspecies differences were observed in the metabolite profiles and quantities. The major human metabolite, 4-hydroxyospemifene, was produced in substantial amounts both in vitro and in vivo in most animal species, except dog, and thus the exposure to this metabolite seems adequate in the most important toxicology species, the rat and the cynomolgus monkey. 4'-Hydroxyospemifene was equally abundant in vitro and in vivo metabolite in mice and dogs, and consequently, its contribution to the total exposure of ospemifene-related activity would be adequately covered in animal experiments. Other ospemifene metabolites were variably detected in different species, but probably they are not of consequence to pharmacology or toxicology of ospemifene.

CONCLUSIONS

Overall, there are quantitative and also some qualitative differences in the metabolism of ospemifene in different species. Generally, in vitro metabolite profiles were predictive for in vivo profiles. The contribution of two major hydroxyl metabolites to activity and toxicity of ospemifene is adequately covered by at least some animal species.

Hospitalizations Due to Adverse Drug Events in the Elderly-A Retrospective Register Study

Adverse drug events (ADEs) are more likely to affect geriatric patients due to physiological changes occurring with aging. Even though this is an internationally recognized problem, similar research data in Finland is still lacking. The aim of this study was to determine the number of geriatric medication-related hospitalizations in the Finnish patient population and to discover the potential means of recognizing patients particularly at risk of ADEs. The study was conducted retrospectively from the 2014 emergency department patient records in Oulu University Hospital. A total number of 290 admissions were screened for ADEs, adverse drug reactions (ADRs) and drug-drug interactions (DDIs) by a multi-disciplinary research team. Customized Naranjo scale was used as a control method. All admissions were categorized into “probable,” “possible,” or “doubtful” by both assessment methods. In total, 23.1% of admissions were categorized as “probably” or “possibly” medication-related. Vertigo, falling, and fractures formed the largest group of ADEs. The most common ADEs were related to medicines from N class of the ATC-code system. Age, sex, residence, or specialty did not increase the risk for medication-related admission significantly (min p = 0.077). Polypharmacy was, however, found to increase the risk (OR 3.3; 95% CI, 1.5–6.9; p = 0.01). In conclusion, screening patients for specific demographics or symptoms would not significantly improve the recognition of ADEs. In addition, as ADE detection today is largely based on voluntary reporting systems and retrospective manual tracking of errors, it is evident that more effective methods for ADE detection are needed in the future.

Tandem mass spectrometric analysis of S- and N-linked glutathione conjugates of pulegone and menthofuran and identification of P450 enzymes mediating their formation

RATIONALE

Menthofuran is a hepatotoxin and a major metabolite of pulegone, a monoterpene found in the essential oils of many mint species. It is bioactivated by cytochrome P450 (CYP) enzymes to reactive metabolites, which may further react with glutathione to form S-linked and N-linked conjugates. The tandem mass spectrometric (MS/MS) fragmentation pathways of rarely observed N-linked conjugates, and the differences to fragmentation of S-linked conjugates, have not been reported in the literature previously, although this information is essential to enable comprehensive MS/MS-based screening methods covering the both types of conjugates.

METHODS

(R)-(+)-Pulegone, (S)-(-)-pulegone, and menthofuran were incubated with a human liver S9 fraction with glutathione (GSH) as the trapping agent. Conjugates were searched with ultra-performance liquid chromatography (UPLC)/orbitrap MS and their MS/MS spectra were measured both in the negative and positive ionization polarities. Menthofuran was also incubated with recombinant human CYP enzymes and GSH to elucidate the CYPs responsible for the formation of the reactive metabolites.

RESULTS

Four GSH conjugates of menthofuran were detected and identified as S- and N-linked conjugates based on MS/MS spectra. N-linked conjugates lacked the characteristic fragments of S-linked conjugates and commonly produced fragments that retained parts of glutamic acid. CYP1A2, 2B6 and 3A4 were observed to produce more GSH conjugates than other CYP isoforms.

CONLUSIONS

Furans can form reactive aldehydes that react in Schiff-base fashion with the free glutamyl-amine of GSH to form N-linked conjugates that have distinct MS/MS spectra from S-linked adducts. This should be taken into account when setting up LC/MS/MS-based detection of glutathione conjugates to screen for reactive metabolites, at least for compounds with a furan moiety. Neutral loss scanning of 178.0412 Da and 290.0573 Da in the positive ionization mode, or neutral loss scanning of 256.0695 Da and 290.0573 Da and precursor ion scanning of m/z 143.0462 in the negative ionization mode, is recommended. Copyright © 2016 John Wiley & Sons, Ltd.

Toxicity of Carboxylic Acid-Containing Drugs: The Role of Acyl Migration and CoA Conjugation Investigated

Many carboxylic acid-containing drugs are associated with idiosyncratic drug toxicity (IDT), which may be caused by reactive acyl glucuronide metabolites. The rate of acyl migration has been earlier suggested as a predictor of acyl glucuronide reactivity. Additionally, acyl Coenzyme A (CoA) conjugates are known to be reactive. Here, 13 drugs with a carboxylic acid moiety were incubated with human liver microsomes to produce acyl glucuronide conjugates for the determination of acyl glucuronide half-lives by acyl migration and with HepaRG cells to monitor the formation of acyl CoA conjugates, their further conjugate metabolites, and trans-acylation products with glutathione. Additionally, in vitro cytotoxicity and mitochondrial toxicity experiments were performed with HepaRG cells to compare the predictability of toxicity. Clearly, longer acyl glucuronide half-lives were observed for safe drugs compared to drugs that can cause IDT. Correlation between half-lives and toxicity classification increased when "relative half-lives," taking into account the formation of isomeric AG-forms due to acyl migration and eliminating the effect of hydrolysis, were used instead of plain disappearance of the initial 1-O-β-AG-form. Correlation was improved further when a daily dose of the drug was taken into account. CoA and related conjugates were detected primarily for the drugs that have the capability to cause IDT, although some exceptions to this were observed. Cytotoxicity and mitochondrial toxicity did not correlate to drug safety. On the basis of the results, the short relative half-life of the acyl glucuronide (high acyl migration rate), high daily dose and detection of acyl CoA conjugates, or further metabolites derived from acyl CoA together seem to indicate that carboxylic acid-containing drugs have a higher probability to cause drug-induced liver injury (DILI).

Peroxisome proliferator-activated receptor alpha, PPARα, directly regulates transcription of cytochrome P450 CYP2C8

The cytochrome P450, CYP2C8, metabolizes more than 60 clinically used drugs as well as endogenous substances including retinoic acid and arachidonic acid. However, predictive factors for interindividual variability in the efficacy and toxicity of CYP2C8 drug substrates are essentially lacking. Recently we demonstrated that peroxisome proliferator-activated receptor alpha (PPARα), a nuclear receptor primarily involved in control of lipid and energy homeostasis directly regulates the transcription of CYP3A4. Here we investigated the potential regulation of CYP2C8 by PPARα. Two linked intronic SNPs in PPARα (rs4253728, rs4823613) previously associated with hepatic CYP3A4 status showed significant association with CYP2C8 protein level in human liver samples (N = 150). Furthermore, siRNA-mediated knock-down of PPARα in HepaRG human hepatocyte cells resulted in up to ∼60 and ∼50% downregulation of CYP2C8 mRNA and activity, while treatment with the PPARα agonist WY14,643 lead to an induction by >150 and >100%, respectively. Using chromatin immunoprecipitation scanning assay we identified a specific upstream gene region that is occupied in vivo by PPARα. Electromobility shift assay demonstrated direct binding of PPARα to a DR-1 motif located at positions –2762/–2775 bp upstream of the CYP2C8 transcription start site. We further validated the functional activity of this element using luciferase reporter gene assays in HuH7 cells. Moreover, based on our previous studies we demonstrated that WNT/β-catenin acts as a functional inhibitor of PPARα-mediated inducibility of CYP2C8 expression. In conclusion, our data suggest direct involvement of PPARα in both constitutive and inducible regulation of CYP2C8 expression in human liver, which is further modulated by WNT/β-catenin pathway. PPARA gene polymorphism could have a modest influence on CYP2C8 phenotype.

Glutathione trapping of reactive drug metabolites produced by biomimetic metalloporphyrin catalysts

RATIONALE

Metalloporphyrins can be useful in the production of drug metabolites, as they enable easier production of oxidative metabolites usually produced by the cytochrome P450 enzymes. Our aim was to test metalloporphyrin-based biomimetic oxidation (BMO) methods for production and S-glutathione trapping of reactive drug metabolites in addition to phase I metabolites.

METHODS

Clozapine, ticlopidine and citalopram were selected as model compounds. These were incubated with the BMO assay and the incubations were analyzed with high-resolution liquid chromatography/mass spectrometry (LC/MS) and tandem mass spectrometry (LC/MS/MS). Additionally, incubations with human liver S9 fraction were performed to compare the results with the BMO assay.

RESULTS

Six glutathione conjugates were identified for clozapine from the S9 incubation, while the BMO assay produced four of these. Four out of the five phase I metabolites produced by S9 were detected using the BMO assay. For ticlopidine, four glutathione conjugates were detected from the S9 incubation, but none of these were observed using the BMO assay. Eight of the nine phase I metabolites produced by S9 incubation were detected in the BMO assay. As expected, no glutathione conjugates were detected for citalopram, and the same three phase I metabolites were detected in both S9 and BMO incubations.

CONLUSIONS

Differences in formation of GSH-trapped reactive metabolites by BMO assay between clozapine and ticlopidine are probably due to different reactive intermediates and reaction mechanisms. The reactive intermediate of clozapine, the nitrenium ion was generated, but the reactive intermediates of ticlopidine, S-oxide and epoxide, were not detected from the incubations. However, the results show that for selected cases the use of biomimetic assays can be used to produce high amounts of S-glutathione conjugates identical to those from liver subfraction incubations, on a scale that is relevant for purification and subsequent identification by NMR spectroscopy; which is often difficult using incubations with liver subfractions.

Effects of cytochrome P450 inhibitors and inducers on the metabolism and pharmacokinetics of ospemifene

PURPOSE

The objectives were to determine the cytochrome P450 (CYP) enzymes involved in the metabolism of ospemifene and its main hydroxylated metabolites and to examine the effects of CYP inhibitors and inducers on ospemifene pharmacokinetics.

METHODS

In vitro metabolism studies were conducted using human liver microsomes; CYP-selective inhibitors and CYP-specific substrates were used to determine the roles of nine CYP isoforms in ospemifene metabolism. Two Phase 1 clinical trials were conducted in healthy postmenopausal women; crossover designs examined the effects of pretreatment with the CYP modulators rifampicin, ketoconazole, fluconazole and omeprazole on ospemifene pharmacokinetics.

RESULTS

Although several CYP inhibitors decreased the in vitro formation of ospemifene metabolites, none of them completely blocked metabolism. Roles for CYP3A4, CYP2C9, CYP2C19 and CYP2B6 in the metabolism of ospemifene and its two main metabolites, 4--hydroxyospemifene and 4'-hydroxyospemifene, were confirmed. The in vivo experiments demonstrated that ospemifene serum concentrations were decreased by rifampicin pretreatment, increased by ketoconazole or fluconazole pretreatment, and minimally affected by omeprazole pretreatment.

CONCLUSIONS

The clinical pharmacokinetic findings and in vitro data suggest that CYP3A4 is important for ospemifene metabolism, but other CYP isoforms and metabolic pathways also contribute. Strong CYP3A or CYP2C9 inducers (e.g. rifampicin) would be expected to decrease the exposure to ospemifene. Ospemifene should be used with caution when coadministered with the modest CYP3A inhibitor ketoconazole and should not be coadministered with the potent CYP3A/CYP2C9/CYP2C19 inhibitor fluconazole. The potent CYP2C19 inhibitor omeprazole is unlikely to cause clinically significant changes in ospemifene pharmacokinetics.

Effects of ospemifene on drug metabolism mediated by cytochrome P450 enzymes in humans in vitro and in vivo

The objective of these investigations was to determine the possible effects of the novel selective estrogen receptor modulator, ospemifene, on cytochrome P450 (CYP)-mediated drug metabolism. Ospemifene underwent testing for possible effects on CYP enzyme activity in human liver microsomes and in isolated human hepatocytes. Based on the results obtained in vitro, three Phase 1 crossover pharmacokinetic studies were conducted in healthy postmenopausal women to assess the in vivo effects of ospemifene on CYP-mediated drug metabolism. Ospemifene and its main metabolites 4-hydroxyospemifene and 4′-hydroxyospemifene weakly inhibited a number of CYPs (CYP2B6, CYP2C9, CYP2C19, CYP2C8, and CYP2D6) in vitro. However, only CYP2C9 activity was inhibited by 4-hydroxyospemifene at clinically relevant concentrations. Induction of CYPs by ospemifene in cultured human hepatocytes was 2.4-fold or less. The in vivo studies showed that ospemifene did not have significant effects on the areas under the plasma concentration-time curves of the tested CYP substrates warfarin (CYP2C9), bupropion (CYP2B6) and omeprazole (CYP2C19), demonstrating that pretreatment with ospemifene did not alter their metabolism. Therefore, the risk that ospemifene will affect the pharmacokinetics of drugs that are substrates for CYP enzymes is low.

Cytochrome P450 2B6: function, genetics, and clinical relevance

Cytochrome P450 (CYP) 2B6 belongs to the set of important hepatic drug-metabolizing CYPs. It makes up roughly 3%-6% of total hepatic CYP content and metabolizes several pharmaceuticals including bupropion, efavirenz, cyclophosphamide, pethidine, ketamine and propofol. The enzyme is susceptible to drug-drug interactions by enzyme induction and inhibition. In addition to drugs, CYP2B6 is able to both detoxify and bioactivate a number of procarcinogens and environmental agents including pesticides and herbicides. There is an extensive interindividual variability in the expression of CYP2B6, which is in part explained by extensive genetic polymorphism. CYP2B6 is one of the most polymorphic CYP genes in humans with over 100 described SNPs, numerous complex haplotypes and distinct ethnic and racial frequencies. This review summarizes the basic properties of CYP2B6 and the main characteristics of clinical relevance.

Metabolism of oxycodone in human hepatocytes from different age groups and prediction of hepatic plasma clearance

Oxycodone is commonly used to treat severe pain in adults and children. It is extensively metabolized in the liver in adults, but the maturation of metabolism is not well understood. Our aim was to study the metabolism of oxycodone in cryopreserved human hepatocytes from different age groups (3 days, 2 and 5 months, 4 years, adult pool) and predict hepatic plasma clearance of oxycodone using these data. Oxycodone (0.1, 1, and 10 μM) was incubated with hepatocytes for 4 h, and 1 μM oxycodone also with CYP3A inhibitor ketoconazole (1 μM). Oxycodone and noroxycodone concentrations were determined at several time points with liquid chromatography–mass spectrometry. In vitro clearance of oxycodone was used to predict hepatic plasma clearance, using the well-stirred model and published physiological parameters. Noroxycodone was the major metabolite in all batches and ketoconazole inhibited the metabolism markedly in most cases. A clear correlation between in vitro oxycodone clearance and CYP3A4 activity was observed. The predicted hepatic plasma clearances were typically much lower than the published median total plasma clearance from pharmacokinetic studies. The data suggests that there are no children-specific metabolites of oxycodone. Moreover, CYP3A activity seems to be the major determinant in metabolic clearance of oxycodone regardless of age group or individual variability in hepatocyte batches.

In vivo-in vitro-in silico pharmacokinetic modelling in drug development: current status and future directions

Although clinical drug trials are indispensable in providing an appropriate background for dosage recommendations, they can provide mechanistic pharmacokinetic information only indirectly with the help of certain biomarkers for pathological, physiological and pharmacological determinants. Thus, to provide such mechanistic information of clinical value, various in vitro and in silico tests and approaches are increasingly employed in drug discovery and development. Integration of the results of these primarily preclinical studies has been made possible by various computational models, such as in vitro-in vivo extrapolation of hepatic clearance or physiologically based pharmacokinetic modelling. In this article, the current status of these modelling approaches is surveyed and some examples are given, highlighting advantages and disadvantages in applying them at various phases of drug development. A new paradigm of model-based drug development is briefly described, and the importance of the approach of integrating all of the information coming from different investigations at all levels--be it in vivo, in vitro or in silico--is emphasized.

True adherence with the Turbuhaler in young children with asthma

OBJECTIVE

To investigate true adherence with a dry powder inhaler, the Turbuhaler (TBH), in children with asthma. True adherence was calculated by multiplying adherence to treatment with inhaler competence, that is correct use of the inhaler.

PATIENTS AND DESIGN

In an 18-month study, children aged 5-10 years with asthma received twice daily budesonide via a TBH. Parents and children were trained in the correct use of the inhaler before the study started. For each inhalation, peak inspiratory flow through the TBH (PIF(TBH)) was recorded with an electronic pneumotachograph. The PIF(TBH) recordings were used to calculate true adherence for the first and last 45-day periods in the study by multiplying adherence in using the device (percentage of days with PIF(TBH) recordings) with inhaler competence (correct use of inhaler defined as PIF(TBH) values >40 l/min).

MAIN OUTCOME MEASURES

True adherence, adherence, inhaler competence and PIF(TBH).

RESULTS

115 children were treated. The mean (morning and evening) true adherence during the first 45 days was 81.6% (range 78.1-86.4%) and during the last 45 days 57.4% (44.0-66.9%). Mean adherence was 86.0% and 59.3%, whereas mean inhaler competence was 94.7% and 96.2%, respectively. Thus the decline in true adherence was due to the decline in adherence. The largest decline in true adherence occurred in older children.

CONCLUSIONS

True adherence with budesonide TBH treatment decreased significantly during the 18-month study due to a decrease in adherence. Inhaler competence with the correct use of the budesonide TBH was high and unchanged over the study period.

Pathway-Targeted Pharmacogenomics of CYP1A2 in Human Liver

The human drug metabolizing cytochrome P450 (CYP) 1A2, is one of the major P450 isoforms contributing by about 5–20% to the hepatic P450 pool and catalyzing oxidative biotransformation of up to 10% of clinically relevant drugs including clozapine and caffeine. CYP1A2 activity is interindividually highly variable and although twin studies have suggested a high heritability, underlying genetic factors are still unknown. Here we adopted a pathway-oriented approach using a large human liver bank (n = 150) to elucidate whether variants in candidate genes of constitutive, ligand-inducible, and pathophysiological inhibitory regulatory pathways may explain different hepatic CYP1A2 phenotypes. Samples were phenotyped for phenacetin O-deethylase activity, and the expression of CYP1A2 protein and mRNA was determined. CYP1A2 expression and function was increased in smokers and decreased in patients with inflammation and cholestasis. Of 169 SNPs in 17 candidate genes including the CYP1A locus, 136 non-redundant SNPs with minor allele frequency >5% were analyzed by univariate and multivariate methods. A total of 13 strong significant associations were identified, of which 10 SNPs in the ARNT, AhRR, HNF1α, IL1β, SRC-1, and VDR genes showed consistent changes for at least two phenotypes by univariate analysis. Multivariate linear modeling indicated that the polymorphisms and non-genetic factors together explained 42, 38, and 33% of CYP1A2 variation at activity, protein and mRNA levels, respectively. In conclusion, we identified novel trans-associations between regulatory genes and hepatic CYP1A2 function and expression, but additional genetic factors must be assumed to explain the full extent of CYP1A2 heritability.

Stable expression, activity, and inducibility of cytochromes P450 in differentiated HepaRG cells

HepaRG cells possess the unique property to differentiate in vitro and to express various functions of mature hepatocytes, including the major cytochromes P450 (P450s). In the present study, we carefully analyzed mRNA expression and activity of the major P450s and their responsiveness to three prototypical inducers, phenobarbital, rifampicin, and omeprazole, in differentiated HepaRG cell cultures over a 4-week period after low and high seeding. Only minor differences were observed in P450 activities when measured by two cocktails of probe substrates, probably related to the choice and/or concentration of substrates. Similar results were obtained from the two cell seeding conditions. Expression and activities of several P450s were dimethyl sulfoxide-dependent. However, basal P450 expression and activities as well as their responsiveness to the prototypical inducers were well maintained over the 4-week period, and a good correlation was observed between transcript levels and corresponding activities. Thus, CYP1A2, CYP2B6, and CYP3A4 were found to accurately respond to their respective prototypical inducers, i.e., omeprazole, phenobarbital, and rifampicin. Likewise, basal expression of several phase II enzymes, transporters, and nuclear receptors, and response to inducers were also well preserved. More genes were found to be induced in HepaRG cells than in primary human hepatocytes, and no marked variation was noticed between the different passages. Taken together, these data support the conclusion that HepaRG cells represent a promising surrogate to primary human hepatocytes for xenobiotic metabolism and toxicity studies.

Effects of selective serotonin reuptake inhibitors on timolol metabolism in human liver microsomes and cryo-preserved hepatocytes

Timolol has been widely used in the treatment of glaucoma. Topically applied, timolol may cause adverse cardiovascular effects due to systemic absorption through the nasolacrimal duct. Timolol is mainly metabolized by cytochrome P450 2D6 (CYP2D6) in the liver. The aim of the present study was to characterize further the metabolism of timolol in vitro. Especially the effect of several drugs such as selective serotonin reuptake inhibitors on the metabolism of timolol was evaluated. In human liver microsomes, four timolol metabolites were identified, in cryo-preserved hepatocytes nine. In both in vitro experiments, the hydroxy metabolite M1 was the main metabolite. The in vivo half-life predicted for timolol was 3.7 hr. in cryo-preserved hepatocytes, corresponding to the half-life of timolol in humans in vivo. Fluoxetine, paroxetine, sertraline, citalopram and fluvoxamine inhibited the formation of M1 in microsomes with IC(50) values of 1.4, 2.0, 3.5, 21 and 20 microM, respectively. In human cryo-preserved hepatocytes, the IC(50) values for fluoxetine, paroxetine and fluvoxamine were 0.7, 0.5 and 5.9 microM, respectively. In conclusion, compounds known to be potent CYP2D6 inhibitors inhibited timolol metabolism in in vitro experiments. The present results strongly suggest that fluoxetine and paroxetine may significantly affect the metabolism of timolol also in vivo and may thus potentiate the adverse cardiovascular effects of topically administered timolol.

Effects of inhaled corticosteroids on metalloproteinase-8 and tissue inhibitor of metalloproteinase-1 in the airways of asthmatic children

BACKGROUND

The effects of corticosteroids on the level and expression of matrix metalloproteinase-8 (MMP-8; collagenase-2) and tissue inhibitors of metalloproteinases (TIMPs) in airway tissue are poorly characterized in vivo.

METHODS

We compared MMP-8 and TIMP-1 levels in induced sputum and their expression in airway inflammatory cells of healthy children (n = 27) and of children with newly diagnosed asthma with mild (n = 20) or moderate symptoms (n = 19), before and after 6 months of treatment with inhaled budesonide.

RESULTS

At baseline, MMP-8 was higher in asthmatic children with moderate symptoms, TIMP-1 was lower and the MMP-8/TIMP-1 ratio was higher in both groups of asthmatic children compared with controls. Inhaled budesonide increased TIMP-1 levels in both groups of asthmatic children and normalized the MMP-8/TIMP-1 ratio, and this paralleled the improvement in forced expiratory volume in 1 s in children with mild symptoms. At baseline, asthmatic children had significantly more MMP-8-positive macrophages than control children, whereas the number of TIMP-1-positive macrophages was almost the same. Budesonide decreased the percentage of MMP-8-positive macrophages and increased that of TIMP-1-positive macrophages; these changes were significant in asthmatic children with mild symptoms.

CONCLUSIONS

Inhaled budesonide normalized the MMP-8/TIMP-1 ratio in asthmatic children by upregulation of TIMP-1 production and downregulation of MMP-8 production by airway macrophages. This change may be a biochemical marker of an effect on airway inflammation and possibly of an ongoing remodeling process that should be further investigated using biopsy specimens.

An evaluation of the cytochrome P450 inhibition potential of selected pesticides in human hepatic microsomes

The goal of this work was to study the ability of 18 pesticides to inhibit selective model activities for all major xenobiotic-metabolizing enzymes, namely CYP1A1/2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1 and 3A4. Generally organophosphorus insecticides were the most potent and extensive inhibitors, especially towards CYP1A1/2 (IC(50) values of chlorpyrifos, fenitrothion and profenofos approximately 3 micro M), CYP2B6 (IC(50) values of chlorpyrifos and fenitrothion 2.5 micro M), CYP2C8 (fenitrothion 4.3 micro M), CYP2C9 (fenitrothion and malathion 4.8 and 2.5 micro M, respectively), CYP2D6 (chlorpyrifos and phenthoate approximately 3 micro M) and CYP3A4 (chlorpyrifos, fenitrothion and phenthoate 3-4 micro M). Otherwise there were quite considerable differences in potency and extent of inhibition between different organophosphates. Pyrethroids were in general very weak or inactive. Deltamethrin and fenvalerate were potent inhibitors of CYP2D6 (IC(50) values of approximately 3 micro M) while lambda-cyhalothrin potently inhibited both CYP2D6 and CYP3A4-mediated activities (IC(50)'s about 3-4 micro M). Some pesticides caused relatively potent inhibitions sporadically (carbendazim, CYP2D6, IC(50) = 12 micro M; atrazine, CYP3A4, IC(50) = 2.8 micro M; glyphosate, CYP2C9, IC(50) = 3.7 micro M; hexaflumuron, IC(50) = 6.0 micro M). With the exceptions of alpha-cypermethrin, cypermethrin, isoproturon, carbaryl and abamectin, most pesticides inhibited relatively potently at least one CYP-selective activity, which may have relevance for potential interactions in occupational exposures and for further studies on the CYP-associated metabolism of respective pesticides.

Budesonide improves decreased airway conductance in infants with respiratory symptoms

OBJECTIVE

Inhaled corticosteroids (ICS) are commonly used to treat wheezing disorders in children, but few studies have investigated the effect of ICS on lung function in infants. We evaluated the efficacy of inhaled budesonide for decreased specific airway conductance (sGaw) as an indication of bronchial obstruction in very young children with recurrent cough and/or wheeze. PATIENTS, DESIGN AND INTERVENTIONS: Functional residual capacity (FRC) and sGaw of steroid-naive children aged 3-26 months with respiratory symptoms were measured using an infant whole-body plethysmograph. Clinically indicated bronchoscopy was performed in 79% of the patients to exclude anatomical abnormalities before randomisation. Children with abnormal lung function and respiratory symptoms were randomised into two treatment groups, receiving either inhaled budesonide (400 microg/day) or placebo with NebuChamber for 6 weeks. Inhaled terbutaline 0.25 mg/dose was used as a rescue medication. Lung function measurements were repeated after 6 weeks.

MAIN OUTCOME MEASURE

Lung function.

RESULTS

44 children with a median age of 11.3 months (range 3.7-25.9) completed the study. Median sGaw improved from a z score of -3.6 to -1.2 (p<0.001) in the budesonide group and from -3.2 to -2.6 (p = 0.033) in the placebo group; between group difference p = 0.014. Improvement in sGaw was more pronounced in children with atopy (p = 0.017). Symptom-free days increased in both the budesonide and placebo groups with no difference between groups.

CONCLUSION

Treatment with inhaled budesonide for 6 weeks improved sGaw in young children with chronic cough or wheeze and bronchial obstruction.

Pharmacogenomics of human liver cytochrome P450 oxidoreductase: multifactorial analysis and impact on microsomal drug oxidation

Aims: NADPH:CYP oxidoreductase (POR) is an essential component of several enzyme systems, including the microsomal CYP monooxygenases. We investigated genetic and nongenetic POR variability and its impact on drug-oxidation activities in human liver microsomes. Material and methods: POR mRNA, protein and activity, as well as ten major drug-oxidation activities, were measured in the microsomes of 150 Caucasian surgical liver samples. Matrix-assisted laser desorption/ionisation-time of flight mass spectrometric assays were established to determine the frequency of 46 selected POR SNPs. Multivariate log-linear regression models, including main effects and two-way interaction terms, and analyses of variance were used to identify statistically significant relationships. Results: POR phenotypes were less variable within the study population as compared with CYP phenotypes. Intronic SNPs g.18557G>A (intron 2), g.25676C>T (intron 3) and g.30986 G>A (intron 10) were associated with various drug-oxidation activities. The common allele POR*28 (A503V) was not associated with any activity or expression changes. Haplotype analysis identified two novel composite alleles POR*36 (P228L plus A503V) and POR*37 (A503V plus V631I). Conclusion: Models that integrate POR and microsomal CYP function are complex and depend on the CYP isozyme, the substrate and numerous genetic and nongenetic factors. Intronic POR variants may influence microsomal CYP activities. These data provide a basis for further studies towards inclusion of POR polymorphisms in pharmacogenomic strategies.

A predominate role of CYP1A2 for the metabolism of nabumetone to the active metabolite, 6-methoxy-2-naphthylacetic acid, in human liver microsomes

Nabumetone, a widely used nonsteroidal anti-inflammatory drug, requires biotransformation into 6-methoxy-2-naphthylacetic acid (6-MNA), a close structural analog to naproxen, to achieve its analgesic and anti-inflammatory effects. Despite its wide use, the enzymes involved in metabolism have not been identified. In the present study, several in vitro approaches were used to identify the cytochrome P450 (P450) enzyme(s) responsible for 6-MNA formation. In human liver microsomes (HLMs) 6-MNA formation displayed monophasic Michaelis-Menten kinetics with apparent K(m) and V(max) values (mean +/- S.D.) of 75.1 +/- 15.3 microM and 1304 +/- 226 pmol/min/mg protein, respectively, and formation rate of 6-MNA varied approximately 5.5-fold (179-983 pmol/min/mg protein). 6-MNA activity correlated strongly with both CYP1A2-mediated phenacetin O-deethylation activity and CYP1A2 protein content (r = 0.85 and 0.74, respectively; p < 0.0001 for both). Additional correlations were found with model activities of CYP2C19 and CYP3A4. Of 11 cDNA-expressed recombinant P450s used, recombinant CYP1A2 was the major form catalyzing the 6-MNA formation with an apparent K(m) of 45 microM and V(max) of 8.7 pmol/min/pmol P450. Minor fractions were catalyzed by recombinant P450s CYP1A1, CYP2B6, CYP2C19, CYP2D6, and CYP2E1. Experiments with P450-selective chemical inhibitors and monoclonal anti-P450 antibodies showed that furafylline, a mechanism-based inhibitor CYP1A2, and anti-CYP1A2 antibody markedly inhibited 6-MNA formation, whereas inhibitors for other P450s did not show significant inhibitory effects. Taken together, these studies indicate that the formation of the active metabolite of nabumetone, 6-MNA, is predominantly catalyzed by CYP1A2 in HLMs with only minor contribution of other P450s.

Liquid chromatography-mass spectrometry in in vitro drug metabolite screening

A combination of high performance liquid chromatography (HPLC) and mass spectrometry (LC/MS) has proven its status as the most powerful analytical tool for screening and identifying drug metabolites in modern drug discovery. These techniques have become irreplaceable for drug metabolism laboratories, providing high amounts of information from a wide variety of samples. This review focuses on the most common and useful applications of these techniques when working on in vitro metabolism, more specifically with screening and identification of chemically stable or reactive metabolites formed via biotransformation reactions. Matching specific tasks and suitable instruments is a recurring consideration; for many reasons, the time-of-flight or orbitrap mass spectrometry provides clearly increased efficiency in metabolite profiling compared to other types of mass spectrometry.

Discovery of substituted sulfonamides and thiazolidin-4-one derivatives as agonists of human constitutive androstane receptor

The constitutive androstane receptor (CAR; NR1I3) is a nuclear receptor responsible for the recognition of potentially toxic endo- and exogenous compounds whose elimination from the body is accelerated by the CAR-mediated inducible expression of metabolizing enzymes and transporters. Despite the importance of CAR, few human agonists are known so far. Following a sequential virtual screening procedure using a 3D pharmacophore and molecular docking approach, we identified 17 novel agonists that could activate human CAR in vitro and enhance its association with the nuclear receptor co-activator SRC1. Selected agonists also increased the expression of the human CAR target CYP2B6 mRNA in primary hepatocytes. Composed of substituted sulfonamides and thiazolidin-4-one derivatives, these agonists represent two novel chemotypes capable of human CAR activation, thus broadening the agonist spectrum of CAR.

Functional pharmacogenetics/genomics of human cytochromes P450 involved in drug biotransformation

We investigated the elimination routes for the 200 drugs that are sold most often by prescription count in the United States. The majority (78%) of the hepatically cleared drugs were found to be subject to oxidative metabolism via cytochromes P450 of the families 1, 2 and 3, with major contributions from CYP3A4/5 (37% of drugs) followed by CYP2C9 (17%), CYP2D6 (15%), CYP2C19 (10%), CYP1A2 (9%), CYP2C8 (6%), and CYP2B6 (4%). Clinically well-established polymorphic CYPs (i.e., CYP2C9, CYP2C19, and CYP2D6) were involved in the metabolism of approximately half of those drugs, including (in particular) NSAIDs metabolized mainly by CYP2C9, proton-pump inhibitors metabolized by CYP2C19, and beta blockers and several antipsychotics and antidepressants metabolized by CYP2D6. In this review, we provide an up-to-date summary of the functional polymorphisms and aspects of the functional genomics of the major human drug-metabolizing cytochrome P450s, as well as their clinical significance.

Daily versus as-needed inhaled corticosteroid for mild persistent asthma (The Helsinki early intervention childhood asthma study)

OBJECTIVE

To compare the effect of inhaled budesonide given daily or as-needed on mild persistent childhood asthma. Patients, design and

INTERVENTIONS

176 children aged 5-10 years with newly detected asthma were randomly assigned to three treatment groups: (1) continuous budesonide (400 microg twice daily for 1 month, 200 microg twice daily for months 2-6, 100 microg twice daily for months 7-18); (2) budesonide, identical treatment to group 1 during months 1-6, then budesonide for exacerbations as needed for months 7-18; and (3) disodium cromoglycate (DSCG) 10 mg three times daily for months 1-18. Exacerbations were treated with budesonide 400 microg twice daily for 2 weeks.

MAIN OUTCOME MEASURES

Lung function, the number of exacerbations and growth.

RESULTS

Compared with DSCG the initial regular budesonide treatment resulted in a significantly improved lung function, fewer exacerbations and a small but significant decline in growth velocity. After 18 months, however, the lung function improvements did not differ between the groups. During months 7-18, patients receiving continuous budesonide treatment had significantly fewer exacerbations (mean 0.97), compared with 1.69 in group 2 and 1.58 in group 3. The number of asthma-free days did not differ between regular and intermittent budesonide treatment. Growth velocity was normalised during continuous low-dose budesonide and budesonide therapy given as needed. The latter was associated with catch-up growth.

CONCLUSIONS

Regular use of budesonide afforded better asthma control but had a more systemic effect than did use of budesonide as needed. The dose of ICS could be reduced as soon as asthma is controlled. Some children do not seem to need continuous ICS treatment.