Population pharmacokinetics and pharmacodynamics of ciclesonide

Assessment of the predictive capability of modelling and simulation to determine bioequivalence of inhaled drugs: A systematic review

OBJECTIVES

There are a multitude of different modelling techniques that have been used for inhaled drugs. The main objective of this review was to conduct an exhaustive survey of published mathematical models in the area of asthma and chronic obstructive pulmonary disease (COPD) for inhalation drugs. Additionally, this review will attempt to assess the applicability of these models to assess bioequivalence (BE) of orally inhaled products (OIPs).

EVIDENCE ACQUISITION

PubMed, Science Direct, Web of Science, and Scopus databases were searched from 1996 to 2020, to find studies that described mathematical models used for inhaled drugs in asthma/COPD.

RESULTS

50 articles were finally included in this systematic review. This research identified 22 articles on in silico aerosol deposition models, 20 articles related to population pharmacokinetics and 8 articles on physiologically based pharmacokinetic modelling (PBPK) modelling for inhaled drugs in asthma/COPD. Among all the aerosol deposition models, computational fluid dynamics (CFD) simulations are more likely to predict regional aerosol deposition pattern in human respiratory tracts. Across the population PK articles, body weight, gender, age and smoking status were the most common covariates that were found to be significant. Further, limited published PBPK models reported approximately 29 parameters relevant for absorption and distribution of inhaled drugs. The strengths and weaknesses of each modelling technique has also been reviewed.

CONCLUSION

Overall, while there are different modelling techniques that have been used for inhaled drugs in asthma and COPD, there is very limited application of these models for assessment of bioequivalence of OIPs. This review also provides a ready reference of various parameters that have been considered in various models which will aid in evaluation if one model or hybrid in silico models need to be considered when assessing bioequivalence of OIPs.

Ciclesonide Impacts Clinicopathological Features of Eosinophilic Esophagitis

BACKGROUND

Eosinophilic esophagitis (EoE) is a chronic allergen-mediated disease of the esophagus. Pharmacologic treatment has largely relied on repurposing corticosteroids. Ciclesonide (CIC) is a corticosteroid for the treatment of asthma with biochemical properties that improve topical potency.

OBJECTIVE

To determine whether CIC decreased clinicopathological features of EoE.

METHODS

We performed a retrospective cohort study of patients with EoE treated with CIC at a pediatric hospital from 2010 to 2019. Data were extracted from the electronic health record. Patients who were prescribed CIC with pre- and post-CIC endoscopic and histological data available were included for analysis.

RESULTS

A total of 281 patients were treated with CIC and 81 met criteria for inclusion. Use of CIC was associated with reduced symptoms including dysphagia (P < .001), abdominal pain (P < .001), vomiting (P = .01), heartburn (P = .02), and behavior changes (P = .02). Average composite endoscopic reference scores decreased from 2.54 to 1.37 (P < .001), with improvement in exudates, edema, and furrows (all P < .001). Peak eosinophil counts decreased from 48 to 23 eosinophils/hpf (P < .001). Forty-three patients (53%) achieved remission (<15 eosinophils/hpf). Esophageal Candida was reported in 1 patient. Fasting morning cortisol concentrations were low in 10 of 31 patients tested. Six of these 10 patients had abnormal adrenocorticotropic hormone stimulation testing, 5 of 6 diagnosed with adrenal insufficiency before transition to CIC and 3 of 6 with subsequent normalization of adrenal function on CIC therapy.

CONCLUSIONS

Patients with EoE treated with CIC experienced significant reductions in clinicopathological features of EoE. CIC can be considered an alternative therapy in patients with known adrenal insufficiency or at risk of developing adrenal insufficiency.

Glucocorticoid induced adrenal insufficiency

Synthetic glucocorticoids are widely used for their anti-inflammatory and immunosuppressive actions. A possible unwanted effect of glucocorticoid treatment is suppression of the hypothalamic-pituitary-adrenal axis, which can lead to adrenal insufficiency. Factors affecting the risk of glucocorticoid induced adrenal insufficiency (GI-AI) include the duration of glucocorticoid therapy, mode of administration, glucocorticoid dose and potency, concomitant drugs that interfere with glucocorticoid metabolism, and individual susceptibility. Patients with exogenous glucocorticoid use may develop features of Cushing's syndrome and, subsequently, glucocorticoid withdrawal syndrome when the treatment is tapered down. Symptoms of glucocorticoid withdrawal can overlap with those of the underlying disorder, as well as of GI-AI. A careful approach to the glucocorticoid taper and appropriate patient counseling are needed to assure a successful taper. Glucocorticoid therapy should not be completely stopped until recovery of adrenal function is achieved. In this review, we discuss the factors affecting the risk of GI-AI, propose a regimen for the glucocorticoid taper, and make suggestions for assessment of adrenal function recovery. We also describe current gaps in the management of patients with GI-AI and make suggestions for an approach to the glucocorticoid withdrawal syndrome, chronic management of glucocorticoid therapy, and education on GI-AI for patients and providers.

An Ultrasensitive LC-APPI-MS/MS Method for Simultaneous Determination of Ciclesonide and Active Metabolite Desisobutyryl-Ciclesonide in Human Serum and Its Application to a Clinical Study

BACKGROUND

The development of more efficient drug delivery devices for ciclesonide inhalation products requires an ultrasensitive bioanalytical method to measure systematic exposure of ciclesonide (CIC) and its active metabolite desisobutyryl-ciclesonide (des-CIC) in humans.

METHOD

Serum sample was extracted with 1-chlorobutane. A reversed-phase liquid chromatography coupled with atmospheric pressure photoionization-tandem mass spectrometry (LC-APPI-MS/MS) method was used for quantification of 1-500 pg/mL for both analytes in a 0.500-mL serum. The analysis time was 4.7 min/injection. CIC-d11 and des-CIC-d11 were used as the internal standards.

RESULTS

Calibration curves showed good linearity (r2 > 0.99) for both analytes. This novel method was precise and accurate with interassay precision and accuracy of all within 9.6% CV and ± 4.0% bias for regular QC samples. Extraction recovery was approximately 85% for both analytes. Serum samples are stable for 3 freeze-thaw cycles, 24 h at bench top, and up to 706 days at both -20 °C and -70 °C. This method was successfully used to support a pharmacokinetic (PK) comparison between the inhalation suspensions and an inhalation aerosol of ciclesonide in healthy participants. The method robustness was also supported by the good incurred sample reanalysis reproducibility.

CONCLUSION

APPI, a highly selective and sensitive ionization source, made possible for quantifying CIC and des-CIC with a lower limit of quantification (LLOQ) of 1 pg/mL in human serum by LC-MS/MS. A 10-fold sensitivity improvement from the most sensitive reported method (LLOQ, 10 pg/mL) is essential to fully characterize the PK profiles of CIC and des-CIC in support of the clinical development of the ciclesonide-related medications for patients.

Towards a Quantitative Mechanistic Understanding of Localized Pulmonary Tissue Retention-A Combined In Vivo/In Silico Approach Based on Four Model Drugs

Increasing affinity to lung tissue is an important strategy to achieve pulmonary retention and to prolong the duration of effect in the lung. As the lung is a very heterogeneous organ, differences in structure and blood flow may influence local pulmonary disposition. Here, a novel lung preparation technique was employed to investigate regional lung distribution of four drugs (salmeterol, fluticasone propionate, linezolid, and indomethacin) after intravenous administration in rats. A semi-mechanistic model was used to describe the observed drug concentrations in the trachea, bronchi, and the alveolar parenchyma based on tissue specific affinities (Kp) and blood flows. The model-based analysis was able to explain the pulmonary pharmacokinetics (PK) of the two neutral and one basic model drugs, suggesting up to six-fold differences in Kp between trachea and alveolar parenchyma for salmeterol. Applying the same principles, it was not possible to predict the pulmonary PK of indomethacin, indicating that acidic drugs might show different pulmonary PK characteristics. The separate estimates for local Kp, tracheal and bronchial blood flow were reported for the first time. This work highlights the importance of lung physiology- and drug-specific parameters for regional pulmonary tissue retention. Its understanding is key to optimize inhaled drugs for lung diseases.

Repurposing drugs as inhaled therapies in asthma

For the first 40 years of the 20th century treatment for asthma occurred in response to an asthma attack. The treatments were given by injection or orally and included the adrenergic agonists adrenalin/epinephrine and ephedrine and a phosphodiesterase inhibitor theophylline. Epinephrine became available as an aerosol in 1930. After 1945, isoprenaline, a non-selective beta agonist, became available for oral use but it was most widely used by inhalation. Isoprenaline was short-acting with unwanted cardiac effects. More selective beta agonists, with a longer duration of action and fewer side-effects became available, including orciprenaline in 1967, salbutamol in 1969 and terbutaline in 1970. The inhaled steroid beclomethasone was available by 1972 and budesonide by 1982. Spirometry alone and in response to exercise was used to assess efficacy and duration of action of these drugs for the acute benefits of beta₂ agonists and the chronic benefits of corticosteroids. Early studies comparing oral and aerosol beta₂ agonists found equivalence in bronchodilator effect but the aerosol treatment was superior in preventing exercise-induced bronchoconstriction. Inhaled drugs are now widely used including the long-acting beta₂ agonists, salmeterol and formoterol, and the corticosteroids, fluticasone, ciclesonide, mometasone and triamcinolone, that act locally and have low systemic bio-availability. Repurposing drugs as inhaled therapies permitted direct delivery of low doses of drug to the site of action reducing the incidence of unwanted side-effects and permitting the prophylactic treatment of asthma.

Use of ICS/LABA (extra-fine and non-extra-fine) in elderly asthmatics

Age represents an exclusion criterion in randomized clinical trials designed to test the efficacy and safety of inhaled drugs in asthma. As a consequence, data on efficacy and safety of inhaled corticosteroid (ICS) and long-acting β2 agonist (LABA) combinations in elderly asthmatics are scanty. Older age is associated with an increased proportion of comorbid conditions; in addition, all organ functions undergo a process of senescence, thus reducing their ability to metabolize the agents. Overall, these age-associated conditions may variably, and often unpredictably, affect the metabolism and excretion of respiratory drugs. However, pharmacological treatment of asthma does not follow specific recommendations in the elderly. In the elderly, the ICS/LABA combinations may carry an increased risk of local indesiderable effects, primarily due to the lack of coordination between activation of the device and inhalation, and systemic adverse events, mainly due to the greater amount of active drug that is available because of the age-associated changes in organ functions as well as drug-to-drug and drug-to-concomitant disease interactions. The extra-fine formulations of ICSs/LABAs, which allow for a more favorable drug deposition in the lungs at a reduced dose, may contribute to overcome this issue. This review revises the efficacy and safety of treatment with ICSs/LABAs, focusing on the main pharmacodynamic and pharmacokinetic properties of the drugs and highlighting the potential risks in the elderly asthmatic population.

Pharmacometric Models for Characterizing the Pharmacokinetics of Orally Inhaled Drugs

During the last decades, the importance of modeling and simulation in clinical drug development, with the goal to qualitatively and quantitatively assess and understand mechanisms of pharmacokinetic processes, has strongly increased. However, this increase could not equally be observed for orally inhaled drugs. The objectives of this review are to understand the reasons for this gap and to demonstrate the opportunities that mathematical modeling of pharmacokinetics of orally inhaled drugs offers. To achieve these objectives, this review (i) discusses pulmonary physiological processes and their impact on the pharmacokinetics after drug inhalation, (ii) provides a comprehensive overview of published pharmacokinetic models, (iii) categorizes these models into physiologically based pharmacokinetic (PBPK) and (clinical data-derived) empirical models, (iv) explores both their (mechanistic) plausibility, and (v) addresses critical aspects of different pharmacometric approaches pertinent for drug inhalation. In summary, pulmonary deposition, dissolution, and absorption are highly complex processes and may represent the major challenge for modeling and simulation of PK after oral drug inhalation. Challenges in relating systemic pharmacokinetics with pulmonary efficacy may be another factor contributing to the limited number of existing pharmacokinetic models for orally inhaled drugs. Investigations comprising in vitro experiments, clinical studies, and more sophisticated mathematical approaches are considered to be necessary for elucidating these highly complex pulmonary processes. With this additional knowledge, the PBPK approach might gain additional attractiveness. Currently, (semi-)mechanistic modeling offers an alternative to generate and investigate hypotheses and to more mechanistically understand the pulmonary and systemic pharmacokinetics after oral drug inhalation including the impact of pulmonary diseases.

The effects of inhaled corticosteroids on growth in children

Inhaled corticosteroids (ICS) are recommended as the first-line therapy for children with persistent asthma. These agents are particularly effective in reducing underlying airway inflammation, improving lung function, decreasing airway hyper-reactivity, and reducing intensity of symptoms in asthmatics. Chronic diseases, such as asthma, have growth-suppressing effects independent of the treatment, which inevitably complicates growth studies. One year studies showed a small, dose-dependent effect of most ICS on childhood growth, with some differences across various ICS molecules, and across individual children. Some ICS at the doses studied did not affect childhood growth when rigorous study designs were used. Most studies did not conform completely with the FDA guidance. The data on effects of childhood ICS use on final adult height are conflicting, but one recent well-designed study showed such an effect, clearly warranting additional studies. In spite of these measurable effects of ICS on childhood growth, it is important to understand that the safety profile of all ICS preparations, with focal anti-inflammatory effects on the lung, is significantly better than oral glucocorticoids.

Pharmacological consequences of inhaled drug delivery to small airways in the treatment of asthma

Small peripheral airways are an important target for the anti-inflammatory treatment of asthma. To make anti-inflammatory drugs (inhaled corticosteroids [ICS]) effectively reach small airways, they should be delivered using inhalation techniques containing high proportions of fine or super-fine particles. Higher proportions of fine particles are associated with higher systemic absorption of ICS leading to an increased risk of endogenous cortisol suppression. Ciclesonide, despite the highest proportion of fine and super-fine particle fractions, is the only ICS not associated with an increased risk of systemic adverse effects, including cortisol suppression. In contrary to ICS, bronchodilators should not be administered to peripheral airways. This does not improve their efficacy and may increase their risk of cardiotoxicity. Thus, from a pharmacological point of view and the theory of aerosols' deposition, fixed combinations of ICS and long-acting beta agonists are always suboptimal. In many cases, the best solution may be to use fine-particle ciclesonide and a non-fine particle beta agonist administered from separate inhalers.

Effects of representative glucocorticoids on TNFα- and CD40L-induced NF-κB activation in sensor cells

Glucocorticoids are an important class of anti-inflammatory/immunosuppressive drugs. A crucial part of their anti-inflammatory action results from their ability to repress proinflammatory transcription factors such as nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) upon binding to the glucocorticoid receptor (GR). Accordingly, sensor cells quantifying their effect on inflammatory signal-induced NF-κB activation can provide useful information regarding their potencies as well as their transrepression abilities. Here, we report results obtained on their effect in suppressing both the TNFα- and the CD40L-induced activation of NF-κB in sensor cells that contain an NF-κB-inducible SEAP construct. In these cells, we confirmed concentration-dependent NF-κB activation for both TNFα and CD40L at low nanomolar concentrations (EC50). Glucocorticoids tested included hydrocortisone, prednisolone, dexamethasone, loteprednol etabonate, triamcinolone acetonide, beclomethasone dipropionate, and clobetasol propionate. They all caused significant, but only partial inhibition of these activations in concentration-dependent manners that could be well described by sigmoid response-functions. Despite the limitations of only partial maximum inhibitions, this cell-based assay could be used to quantitate the suppressing ability of glucocorticoids (transrepression potency) on the expression of proinflammatory transcription factors caused by two different cytokines in parallel both in a detailed, full dose-response format as well as in a simpler single-dose format. Whereas inhibitory potencies obtained in the TNF assay correlated well with consensus glucocorticoid potencies (receptor-binding affinities, Kd, RBA, at the GR) for all compounds, the non-halogenated steroids (hydrocortisone, prednisolone, and loteprednol etabonate) were about an order of magnitude more potent than expected in the CD40 assay in this system.

Comparison of the efficacy of ciclesonide with that of budesonide in mild to moderate asthma patients after step-down therapy: a randomised parallel-group study

BACKGROUND

Inhaled corticosteroids (ICSs) are widely used in asthma control. Ciclesonide (CIC) is an ICS with on-site lung activation for potent anti-inflammatory activity.

AIMS

This study aimed to compare the clinical benefit of CIC with budesonide (BUD) in step-down therapy.

METHODS

A total of 150 patients with mild-to-moderate asthma well controlled by a combination of ICS and long-acting β2-agonist were randomised to receive either CIC 320 μg (n=75) once daily or 2 inhalations of BUD 200 μg (n=75) twice daily for 12 weeks. The forced expiratory volume in 1s (FEV1), maximum mid-expiratory flow (MMEF) and asthma control test (ACT) scores were measured. Ranked stratification of patients and physicians was assessed.

RESULTS

Drug adherence was significantly higher in the CIC group than in the BUD group (76.0% vs. 58.7%, P=0.03). The FEV1 and MMEF remained stable throughout the 12-week CIC treatment. In the BUD group, FEV1 significantly decreased at weeks 4 and 12. MMEF had a higher value in the CIC group than in the BUD group. Both patients and physicians ranked CIC over BUD.

CONCLUSIONS

CIC is more effective and has better drug adherence than BUD as step-down treatment when asthma is well controlled by combination therapy.

Inhalational Steroids and Iatrogenic Cushing's Syndrome

Bronchial asthma (BA) and Allergic rhinitis (AR) are common clinical problems encountered in day to day practice, where inhalational corticosteroids (ICS) or intranasal steroids (INS) are the mainstay of treatment. Iatrogenic Cushing syndrome (CS) is a well known complication of systemic steroid administration. ICS /INS were earlier thought to be safe, but now more and more number of case reports of Iatrogenic Cushing syndrome have been reported, especially in those who are taking cytochrome P450 (CYP 450) inhibitors. Comparing to the classical clinical features of spontaneous Cushing syndrome, iatrogenic Cushing syndrome is more commonly associated with osteoporosis, increase in intra-ocular pressure, benign intracranial hypertension, aseptic necrosis of femoral head and pancreatitis, where as hypertension, hirsuitisum and menstrual irregularities are less common. Endocrine work up shows low serum cortisol level with evidence of HPA (hypothalamo-pituitary-adrenal) axis suppression. In all patients with features of Cushing syndrome with evidence of adrenal suppression always suspect iatrogenic CS. Since concomitant administration of cytochrome P450 inhibitors in patients on ICS/INS can precipitate iatrogenic CS, avoidance of CYP450 inhibitors, its dose reduction or substitution of ICS are the available options. Along with those, measures to prevent the precipitation of adrenal crisis has to be taken. An update on ICS-/INS- associated iatrogenic CS and its management is presented here.

Pharmacokinetics and pharmacodynamics of inhaled glucocorticoids

Inhaled corticosteroids are used widely to treat asthma. A number of different steroids and inhalation devices are available. The pharmacokinetic and pharmacodynamic properties of the different inhaled corticosteroids may influence their efficacy and safety profiles. Properties of an ideal inhaled corticosteroid include low oropharyngeal deposition, low oral bioavailability, high lung deposition, long pulmonary residence times, high receptor affinity, high plasma protein binding, and efficient systemic clearance. Attention to these parameters might help clinicians optimally balance between the safety and efficacy of inhaled corticosteroids in treating individual patients with asthma.

Safety and efficacy of inhaled corticosteroids (ICS) in children with asthma

Inhaled corticosteroids (ICS) are the guideline-preferred preventative therapy for persistent asthma of all severity levels and for all ages, including children. While these drugs are unquestionably efficacious, concerns of adverse systemic effects limit patient compliance with treatment regimens and thus the attainable benefits. Suppression of bone growth, bone density, and HPA axis function, in addition to cataract formation and elevated intraocular pressure/glaucoma, have been associated with ICS use. This review will focus on recent developments in the safety and efficacy of ICS as compared to oral CS corticosteroids and the achievement of a balance between risk and benefit in optimizing ICS therapy.

Allometric modeling of ciclesonide, a nonhalogenated glucocorticoid, and its active metabolite, desisobutyrylciclesonide, using animal-derived pharmacokinetic parameters

Ciclesonide, a novel glucocorticosteroid, through a rapid metabolism to desisobutyryl-ciclesonide (des-ciclesonide), provides an effective treatment option for asthma episodes by the inhaled route of administration. The availability of pharmacokinetic parameters (clearance [CL/F]; volume of distribution [Vd/F]; elimination half-life [T(½)]; and elimination rate constant [Kel]) in mice, rats, rabbits, and dogs enabled the prediction of human parameter values for des-ciclesonide using the well-accepted tool of allometry after intravenous administration of ciclesonide. However, as a result of the rapid conversion of ciclesonide, it was possible to perform allometry for the CL parameter only. Simple allometry (CL = 4.781W⁰·⁷⁸⁷⁴; R² = 0.9968) appeared to predict the CL of ciclesonide in close proximity of the observed value (observed: 101.25 L/h versus predicted: 135.62 L/h). In a similar manner, simple allometry predicted the human pharmacokinetic parameters of des-ciclesonide (CL/F, Vd/F, T(½), and Kel) within a two- to threefold range of the observed values. The allometric equations for des-ciclesonide parameter values were: CL/F = 4.8166W⁰·⁴⁹² (R² = 0.8598); Vd/F = 19.052W⁰·⁶³² (R² = 0.9049); T(½) = 3.7598W⁻⁰·¹⁶¹¹(R² = 0.8551); and Kel = 0.1832W⁰·¹⁵⁹⁶ (R² = 0.8632). In conclusion, the data suggested that allometry tool may be amenable for the prediction of the pharmacokinetic parameters of des-ciclesonide despite differences in the conversion rates and bioavailability of the active metabolite in various animal species.

THE PARADOXICAL EFFECT ON PNEUMONIA OF CHRONIC INHALED CORTICOSTEROIDS

Community-acquired pneumonia (CAP) is the leading infectious cause of death in developed countries. Several studies have shown that the risk of pneumonia is increased in patients with Chronic Obstructive Pulmonary Disease (COPD) who are receiving chronic inhaled corticosteroids (ICS). The impact of ICS On pneumonia prognosis is controversial. Recent studies have shown that COPD patients with prior ICS use have less mortality after developing CAP as compared with patients with COPD without prior ICS use. This review discusses the association of ICS and the risk of CAP and its association with clinical outcomes in patients with COPD and pneumonia.

A geometrical approach to the PKPD modelling of inhaled bronchodilators

The present work introduces a new method to model the pharmacokinetics (PK) and pharmacodynamics (PD) of an inhaled dose of bronchodilator, alternative to classic compartmental representations or computational fluid dynamics. A five compartment PK model comprising alimentary tract absorption (gut), bronchial tree mucosa, bronchial muscles, plasma, and elimination/excretion pathways has been developed. Many anatomical and physiological features of the bronchial tree depend on bronchial generation or on mean distance from the larynx. Among these are diameters, resistances, and receptor density, which determine together the local response to the inhaled drug; integrating these local responses over the whole bronchial tree allows an approximation of total bronchodilator response and airflow resistance. While the PK part of the model reflects classical compartmental assumptions, the PD part adds a simplified geometrical and functional description of the bronchial tree to a typical empirical model of local effect on bronchial muscle, leading to the direct computation of the approximate forced expiratory volume in 1 s (FEV(1)). In the present work the construction of the model is detailed, with reference to literature data. Simulation of a hypothetical asthmatic subject is employed to illustrate the behaviour of the model in representing the evolution over time of the distribution and pharmacological effect of an inhaled dose of a bronchodilator. The relevance of particle size and drug formulation diffusivity on therapeutic efficacy is discussed.

Adrenal suppression: A practical guide to the screening and management of this under-recognized complication of inhaled corticosteroid therapy

Inhaled corticosteroids (ICSs) are the most effective anti-inflammatory agents available for the treatment of asthma and represent the mainstay of therapy for most patients with the disease. Although these medications are considered safe at low-to-moderate doses, safety concerns with prolonged use of high ICS doses remain; among these concerns is the risk of adrenal suppression (AS). AS is a condition characterized by the inability to produce adequate amounts of the glucocorticoid, cortisol, which is critical during periods of physiological stress. It is a proven, yet under-recognized, complication of most forms of glucocorticoid therapy that can persist for up to 1 year after cessation of corticosteroid treatment. If left unnoticed, AS can lead to significant morbidity and even mortality. More than 60 recent cases of AS have been described in the literature and almost all cases have involved children being treated with ≥500 μg/day of fluticasone.

The risk for AS can be minimized through increased awareness and early recognition of at-risk patients, regular patient follow-up to ensure that the lowest effective ICS doses are being utilized to control asthma symptoms, and by choosing an ICS medication with minimal adrenal effects. Screening for AS should be considered in any child with symptoms of AS, children using high ICS doses, or those with a history of prolonged oral corticosteroid use. Cases of AS should be managed in consultation with a pediatric endocrinologist whenever possible. In patients with proven AS, stress steroid dosing during times of illness or surgery is needed to simulate the protective endogenous elevations in cortisol levels that occur with physiological stress.

This article provides an overview of current literature on AS as well as practical recommendations for the prevention, screening and management of this serious complication of ICS therapy.

Efficacy and safety of ciclesonide in patients with severe asthma: a 12-week, double-blind, randomized, parallel-group study with long-term (1-year) follow-up

OBJECTIVE

To investigate the efficacy and safety of ciclesonide in patients with severe asthma over a 1-year period.

RESEARCH DESIGN AND METHODS

Patients aged 18 - 75 years with persistent asthma were enrolled in a 12-week, double-blind, randomized study and treated with ciclesonide 320 or 640 μg twice daily (b.i.d.) with the option of continuing in a 40-week extension phase (EP).

MAIN OUTCOMES MEASURES

Change in morning peak expiratory flow (PEF) from baseline to 12 weeks and safety over 1 year.

RESULTS

365 patients were randomized and 275 continued into the EP. During 12 weeks' treatment, morning peak expiratory flow significantly increased by 16 l/min (p < 0.001) and 14 l/min (p = 0.001) in the 320 and 640 μg b.i.d. groups, respectively. Both doses significantly reduced total asthma symptom scores by 0.29 (p < 0.0001). In both groups, the incidence of adverse effects (AEs) was low and mean cortisol levels in serum and urine were not suppressed during the EP.

CONCLUSIONS

Ciclesonide 320 μg b.i.d. sustained lung function and asthma symptoms in patients with severe asthma over 12 weeks' treatment, and maintained lung function during a 40-week EP; ciclesonide 640 μg b.i.d. did not provide additional benefits. Long-term use of ciclesonide was not associated with increased local AEs or negative effects on cortisol levels.

Similar Results in Children with Asthma for Steady State Pharmacokinetic Parameters of Ciclesonide Inhaled with or without Spacer

Background:

Ciclesonide is an inhaled corticosteroid administered by a metered dose inhaler (MDI) to treat bronchial asthma. After inhalation, the inactive ciclesonide is converted by esterases in the airways to active metabolite desisobutyryl-ciclesonide (des-CIC).

Aim:

To compare the pharmacokinetic (PK) parameters of des-CIC in children after administration of therapeutic dose of ciclesonide with and without spacer (AeroChamber Plus^™).

Methods:

Open-label, 3 period, cross over, repeated dose, PK study in 37 children with mild to moderate stable asthma (age: 6–11 y; body weight: 20–53 kg). During each 7-day treatment period, ciclesonide was inhaled once in the morning: A) 160 μg MDI with spacer, B) 80 μg MDI with spacer, and C) 160 μg MDI without spacer. Serum PK parameters of ciclesonide and des-CIC were determined on Day 7 of each period. The primary PK parameters were the AUC_τ and C_max for des-CIC.

Results:

Inhaling ciclesonide with spacer led to a dose proportional systemic exposure (AUC_τ) of des-CIC (0.316 μg*h/L for 80 μg and 0.663 μg*h/L for 160 μg). The dose-normalized systemic exposure for des-CIC (based on AUC_τ) was 27% higher after inhalation of ciclesonide 80 μg or 160 μg with spacer than without spacer; the corresponding C_max values for des-CIC were, respectively, 63% and 55% higher with spacer. No clinically relevant abnormalities or adverse drug reactions were observed.

Conclusions:

Inhalation of therapeutic ciclesonide dose with spacer led to a slight increase in the systemic exposure of des-CIC, which does not warrant dose adjustment.

Drug metabolism and pharmacokinetics

In this article, aspects of absorption, distribution, metabolism, and excretion have been described bearing in mind the pathogenesis of allergic diseases and their possible therapeutic opportunities. The importance of the routes of administration of the different therapeutic groups has been emphasized. The classical aspects of drug metabolism and disposition related to oral administration have been reviewed, but special emphasis has been given to intranasal, cutaneous, transdermal, and ocular administration as well as to the absorption and the subsequent bioavailability of drugs. Drug-metabolizing enzymes and transporters present in extrahepatic tissues, such as nasal mucosa and the respiratory tract, have been particularly discussed. As marketed antiallergic drugs include both racemates and enantiomers, aspects of stereoselective absorption, distribution, metabolism, and excretion have been discussed. Finally, a new and promising methodology, microdosing, has been presented, although it has not yet been applied to drugs used in the treatment of allergic diseases.

Clinical pharmacokinetic and pharmacodynamic profile of inhaled ciclesonide

Asthma is a chronic inflammatory disease of the airways, and inhaled corticosteroids (ICSs) are recommended as first-line therapy for persistent asthma of all severities. Ciclesonide is a novel ICS, which is administered as an aerosol solution in a metered-dose inhaler, using hydrofluoroalkane-134a as a propellant. Because of the high respirable particle fraction, high pulmonary deposition is obtained in patients, which constitutes the basis of effective therapeutic action. The parent compound, ciclesonide, is pharmacologically inactive and is activated in the target organ, the lung, to form its only pharmacologically active metabolite, desisobutyryl-ciclesonide (des-CIC). Low oral deposition combined with minimal formation of des-CIC in the oropharynx may minimize the typical oropharyngeal adverse events associated with ICSs. Low oral bioavailability, rapid clearance and high protein binding reduce pharmacologically relevant systemic exposure. The unique pharmacokinetic and pharmacodynamic profile of ciclesonide offers a rationale that supports the favourable risk-benefit profile observed in clinical trials in patients with persistent asthma.

Similar efficacy of ciclesonide versus prednisolone to treat asthma worsening after steroid tapering

RATIONALE

Oral corticosteroids effectively treat asthma exacerbations but are associated with well-described side effects.

OBJECTIVE

This study compared the efficacy and safety of a high dose of an inhaled corticosteroid with oral prednisolone in patients with worsening of their asthma after medication withdrawal.

METHODS

Patients tapered off their inhaled corticosteroids until they reached predefined criteria of "worsening asthma". Randomized patients (n=130) were treated double blind with either ciclesonide 800mug twice daily (starting with 800mug hourly for 3h after randomization) or prednisolone 40mg once daily for 2 weeks. Spirometry, daily asthma symptoms, morning and evening peak expiratory flow and blood parameters were assessed in all, methacholine challenge and inflammatory measures were determined in induced sputum in a subset of patients.

RESULTS

Ciclesonide was as effective as prednisolone in improving forced expiratory flow in 1s, morning peak expiratory flow and symptoms, the latter improving more rapidly with ciclesonide. No differences were found in methacholine responsiveness or inflammatory measures in sputum or blood. Ciclesonide caused significantly less reduction in morning plasma cortisol levels (p<0.0001).

CONCLUSION

This study shows that inhaled ciclesonide (800mug twice daily) has comparable efficacy to oral prednisolone (40mg once daily) to regain asthma control in patients with asthma worsening. The more rapid onset and smaller effect on cortisol suppression suggest a better safety profile of ciclesonide.

Inhaled corticosteroids for asthma: are they all the same?

OBJECTIVES

To assess similarities and differences among currently available inhaled corticosteroids (ICS) for treatment of asthma, with special emphasis on factors that may affect the relative safety of these medications.

METHODS

PubMed was searched for relevant reviews and original articles. Information from these studies was synthesized and critically assessed.

RESULTS

Differences in corticosteroid formulations and delivery systems can create variations in therapeutic efficacy. Chemical properties of the various corticosteroids may also affect their relative safety. Ciclesonide and beclomethasone dipropionate are administered as prodrugs activated by enzymes present in the lungs but not the oropharynx. Corticosteroid-specific adverse effects in the oropharynx are thus avoided, although formulation-specific effects may remain. Other adverse effects require systemic availability, either via the gastrointestinal tract or the lung. Once they enter the systemic circulation, all ICS are rapidly metabolized by the liver. Oral bioavailability of ICS such as fluticasone, ciclesonide and mometasone is minimal, as a result of their essentially complete first-pass metabolism in the liver. Ciclesonide also undergoes extrahepatic metabolism that eliminates it even more rapidly. Additionally, ciclesonide and mometasone exhibit very high levels of binding to serum proteins that reduces their ability to stimulate glucocorticoid receptors outside the lung.

CONCLUSIONS

Despite acting by similar mechanisms, currently available ICS and their delivery systems differ in ways that can potentially affect both safety and therapeutic effectiveness for individual patients.

Ciclesonide: a safe and effective inhaled corticosteroid for the treatment of asthma

Ciclesonide is a novel inhaled corticosteroid used in the continuous treatment of mild-to-severe asthma. Its formulation and mechanism of action yield a low oral and systemic bioavailability, and high pulmonary deposition. In multiple clinical trials, ciclesonide is at least as effective as either fluticasone propionate or budesonide at symptom control, while in many cases having improved safety outcomes and tolerability. The improved safety and comparable efficacy profiles of ciclesonide demonstrated in current studies could potentially yield a treatment option that may lead to improved adherence and outcome.

Cortisol suppression as a surrogate marker for inhaled corticosteroid-induced growth retardation in children

Exposure of inhaled corticosteroids (ICSs) in pediatrics results in adrenal suppression and growth inhibition. The objective of this study was to assess the relationship of ICS mediated growth retardation with cortisol suppression in asthmatic children. A meta-analysis approach was performed with 33 published articles. Growth velocity (GV) data were obtained from the literature for evaluation of growth. Cumulative cortisol suppression within 24h (CCS%) was calculated at steady state with a validated algorithm. Consolidated GV and CCS% data were employed for model development. A linear mixed effects model was developed to adequately describe the relationship between GV and CCS%. No impact of tested covariates was observed. Population estimate of the rate of change in GV was -0.06cm/year/CCS% (12.7%, coefficient of variation) for both stadiometry and knemometry methods. However, GV from stadiometry is expected to be approximately three fold higher than that from knemometry when cortisol suppression was not presented. The final model was evaluated with posterior predictive check and pattern check approaches. The results from this study elucidate CCS% as an excellent predictor of ICS mediated growth retardation in asthmatic children.

Ciclesonide nasal spray: in allergic rhinitis

Ciclesonide nasal spray delivers the corticosteroid ciclesonide as a hypotonic spray via a metered-dose manual pump. Systemic exposure to ciclesonide and its active metabolite desisobutyryl-ciclesonide is low after intranasal administration. High protein binding (approximately 99%) and rapid first-pass clearance further reduce systemic exposure to the drug. In well designed trials, intranasal ciclesonide 200 microg once daily for 2-4 weeks was more effective than placebo in terms of improving nasal symptoms in adolescents and adults with moderate to severe seasonal allergic rhinitis. Quality of life measures were statistically significantly improved in ciclesonide relative to placebo recipients during the first 2 weeks of therapy. Similarly, in adolescents and adults with moderately severe perennial allergic rhinitis, ciclesonide 200 microg once daily was more effective than placebo in terms of reducing nasal symptoms in well designed trials of 6 weeks' and 1 year's duration. Improvements relative to placebo in quality of life measures were not considered clinically relevant. Ciclesonide nasal spray was generally well tolerated in these clinical trials; most adverse events were mild to moderate in intensity.

Glucocorticoid receptor binding: a biphasic dependence on molecular size as revealed by the bilinear LinBiExp model

For corticosteroids, receptor-binding affinity (RBA) at the glucocorticoid receptor (GR) is a major determinant of therapeutic potential. Here, the results of a comprehensive quantitative analysis of relative RBA (rRBA) data obtained from more than a hundred active structures are reported. Because of a clear biphasic size-dependence, the recently introduced linearized biexponential (LinBiExp) model provided very good fit: for steroids that satisfy the main binding criteria at the GR, it accounts for close to 80% of the variability in the free energy of binding DeltaG0 (or logrRBA) data by using only two descriptors: calculated molecular volume and an indicator variable for the presence of 6alpha/9alpha-halogen or cyclic 16,17-acetal moieties. Accordingly, binding is strongest for corticosteroids close to an ideal size that is large enough to provide as large nonspecific (van der Waals-type) interactions as possible, but is not too large to have difficulty fitting due to size-limitations at the binding site. Binding affinity is dramatically increased by 6alpha- or 9alpha-halogenation or introduction of a cyclic 16,17-acetal moiety (in average, about 7-fold), but there is no significant increase after the first substitution. Known highly active glucocorticoids, such as betamethasone 17-monopropionate, fluticasone propionate, or mometasone furoate, indeed satisfy both of these criteria. For small-enough structures, the obtained size-dependency (slope) of the free energy of binding suggest that, as long as only nonspecific interactions are involved, addition of a methylene-sized non-hydrogen atom to the ligand structure increases DeltaG0 on average by about 1.5 kJ/mol, corresponding to an almost doubling of the binding affinity.

Assessment of the long-term safety of inhaled ciclesonide on growth in children with asthma

OBJECTIVE

To assess the effects of the new inhaled corticosteroid ciclesonide on growth in children with asthma.

METHODS

We performed a multicenter, randomized, double-blind, placebo-controlled study to assess the effects of inhaled ciclesonide on growth in children with mild, persistent asthma. After a 6-month run-in period, 661 prepubertal children who were aged 5.0 to 8.5 years were randomly assigned to once-daily morning treatment for 1 year with ciclesonide 40 or 160 microg (ex-actuator) or placebo, followed by a 2-month follow-up period. The primary end point was the linear growth velocity (linear regression estimate) over the double-blind treatment period. Growth was recorded as the median of 4 stadiometer measurements. Adverse events and 10-hour overnight and 24-hour urinary free cortisol levels were also assessed.

RESULTS

Mean linear growth velocity during run-in was comparable between groups: 160 microg, 6.20 cm/year; 40 microg, 6.59 cm/year; placebo, 6.49 cm/year. Mean differences from placebo (5.75 cm/year) in growth velocity over the double-blind treatment period were -0.02 cm/year for ciclesonide 40 microg and -0.15 cm/year for ciclesonide 160 microg. Both ciclesonide treatments were noninferior to placebo with respect to growth velocity. The overall incidence of adverse events was comparable between groups, and no significant changes in 10-hour overnight or 24-hour urinary free cortisol levels were noted between groups during the double-blind treatment period.

CONCLUSIONS

Ciclesonide demonstrated no detectable effect on childhood growth velocity, even at the highest dosage, which may ease concerns about systemic adverse events.

Similar efficacy of ciclesonide once daily versus fluticasone propionate twice daily in patients with persistent asthma

This 12-week, double-blind, parallel-group study compared the efficacy and safety of once daily ciclesonide and twice daily fluticasone propionate in patients aged 12-75 years with persistent asthma. Patients were randomized to once-daily ciclesonide 80 micro g (n = 278) or 160 micro g (n = 271), or twice daily fluticasone propionate 88 micro g (n = 259) (all ex-actuator). Significant improvements from baseline were seen in all three treatment groups for forced expiratory volume in 1 second, asthma symptom scores and rescue medication use (all p < 0.0001). Asthma exacerbation rates were low (each ciclesonide group, n = 2; fluticasone group, n = 1). Adverse event reporting indicated good tolerability. Once daily ciclesonide 80 micro g or 160 micro g showed comparable efficacy and tolerability to twice daily fluticasone propionate 88 micro g in persistent asthma.

Randomized comparison of ciclesonide 160 and 640 microg/day in severe asthma

OBJECTIVE

Demonstrating clinical benefit of higher doses of inhaled corticosteroids in asthma is frequently problematic owing to their relatively flat dose-response curve in this condition. In this study we compared the efficacy and safety of a fourfold difference in the dose of ciclesonide-ciclesonide 320 microg twice daily (CIC640) versus ciclesonide 160 microg once daily (CIC160)-in patients with severe persistent asthma.

METHODS

Patients with bronchial asthma (6 months) were included in this randomized, double-blind study. After receiving fluticasone propionate 250 microg twice daily during run-in, patients were randomized to CIC160 (n=339) or CIC640 (n=341) for 12 weeks. Primary endpoints were time to first asthma exacerbation and forced expiratory volume in 1s (FEV(1)). Secondary endpoints included other lung function variables, asthma symptom scores and rescue medication use (RMU).

RESULTS

Asthma exacerbations occurred in 12.7% of patients receiving CIC160 and 6.7% receiving CIC640. CIC640 was superior for time to first exacerbation (p=0.0050, one-sided). FEV(1) increased significantly with CIC160 and CIC640 (least squares mean+/-SE of mean: 269+/-31 and 332+/-31 mL, respectively; p<0.0001), with no significant difference between groups. Change in % predicted FEV(1) and morning peak expiratory flow (PEF) were significantly higher with CIC640 (p<0.05). Asthma symptom score sums and RMU decreased in both groups; CIC640 was statistically superior (p=0.0108 and 0.0005, respectively). No unexpected adverse events were reported in either group and the majority of the events reported were mild or moderate in intensity. No significant changes in serum cortisol were observed from the baseline to the study end. Small decreases in creatinine-adjusted 24h urine cortisol levels from baseline were seen in both the treatment groups, which, due to the large patient numbers, were statistically significant (p<0.05); however, no dose-response effect was seen and the difference between groups was not significant (p=0.7892).

CONCLUSION

CIC640 was superior to CIC160 for time to first exacerbation, % predicted FEV1, morning PEF, asthma symptom score sum and RMU in patients with severe asthma; both doses had similar tolerability profiles and no significant changes in serum cortisol were seen in either treatment group.

Key barriers to optimal management of adult asthma in Australia: physician and patient perspectives

OBJECTIVE

Despite recent advances in asthma treatment, its management in many patients remains sub-optimal. The aim of the Global Asthma Physicians and Patient (GAPP) survey was to identify barriers to optimal asthma management and to explore the content and dynamics of physician-patient communications. Here we present the key findings for adults with asthma in Australia.

RESEARCH DESIGN AND METHODS

Patients with asthma aged > or = 18 years and physicians who treat adults (generalists; specialists) participated in telephone interviews conducted in May-June 2005, using close-end questionnaires. The survey examined physicians' beliefs and prescribing habits; patients' experiences with asthma; doctor-patient communication; satisfaction with asthma medications and interest in new asthma treatment.

RESULTS

A total of 101 adults with asthma and 100 physicians treating asthma patients in Australia completed the survey. Overall, key barriers to optimal asthma management included medication side effects, treatment compliance and patient education. These barriers may be exacerbated by poor patient-physician communication that fails to address patients concerns regarding side effects and may lead to poor treatment compliance. Both physicians and patients expressed safety concerns regarding the long-term use of inhaled corticosteroid and both groups would welcome new treatment options with improved safety profiles, efficacy and once-daily dosing.

CONCLUSION

From both a physician and patient perspective, the safety profile of asthma medication constitutes a key factor in promoting treatment compliance and, ultimately, treatment outcomes. The results highlight discrepancies in perceived patient-physician communication and a need for improved patient education in asthma management.

Pharmacotherapy of asthma

The pharmacotherapy of asthma is a complex and evolving topic. A detailed understanding of the pathophysiologic processes involved in the asthmatic response forms the basis for understanding the actions of drugs used to treat this condition. Likewise, a solid comprehension of the medicinal chemistry and pharmacologic properties of the numerous agents involved in the treatment of asthma is critical for rationalizing drug choices and understanding potential side effects. Asthma is addressed at several points in the PharmD curriculum at South University including in the Pathophysiology (quarter 2), Integrated Sequence III (quarter 6), and Critical Care (quarter 9) courses. Various teaching strategies are employed throughout, along with weekly case-based recitations. The content presented here includes a synopsis of the pathophysiology and pharmacology from our Integrated Sequence III block on inflammatory diseases and asthma. A short review of pertinent pathophysiology is followed by a detailed presentation on the various classes of asthma drugs which includes their chemistry, mechanism of action, pharmacokinetics, toxicity, and interactions. This presentation is designed to prepare students for asthma therapeutics, which follows next in the schedule. The complexities of asthma pharmacotherapy are stressed along with current controversies and future drug development.

Modulation of human lung fibroblast functions by ciclesonide: evidence for its conversion into the active metabolite desisobutyryl-ciclesonide

BACKGROUND

Ciclesonide, an inhaled corticosteroid administered as inactive compound with almost no binding affinity for the glucocorticoid receptor, is clinically effective in asthma being converted by airway epithelial cells into its active metabolite desisobutyryl-(des)-ciclesonide.

AIM

To evaluate whether ciclesonide could directly modulate in vitro bronchial fibroblast functions being converted into des-ciclesonide by these pluripotent cells involved in the regulation of airway inflammation and remodelling.

METHODS

Ciclesonide (0.09-9.0 microM) was added to a human adult lung fibroblast cell line (CCL-202), seeded in medium in the presence of the following cytokines and growth factors: (a) basic fibroblast growth factor (bFGF) for cell proliferation, measured by tritiated thymidine ([3H]TdR) incorporation; (b) tumour necrosis factor (TNF)-alpha, to stimulate intercellular adhesion molecule (ICAM)-1 expression and monocyte chemoattractant protein-1 (MCP-1) and eotaxin release, evaluated by flow cytometry and ELISA, respectively; (c) transforming growth factor (TGF)-beta1, for induction of alpha smooth muscle actin (alpha-SMA) protein expression and modification of the organization of alpha-SMA stress fibres, evaluated by Western blot analysis and fluorescence microscopy.

RESULTS

The presence of ciclesonide in cell cultures induced a significant downregulation of: (a) bFGF-induced fibroblast proliferation and TNF-alpha-induced ICAM-1 expression, at the 0.3-9.0 microM concentrations (p<0.05); (b) TNF-alpha-induced MCP-1 release, at all the concentrations tested (p<0.05); (c) TNF-alpha-induced eotaxin release, at the three highest concentrations (0.9-9.0 microM) (p<0.05); (d) TGF-beta1-induced of alpha-SMA protein expression at the 0.3-3.0 microM concentrations, associated with a reduction in the organization of alpha-SMA stress fibres.

CONCLUSIONS

These data show at cellular level an effective anti-inflammatory activity of ciclesonide on human lung fibroblasts and support the hypothesis that also these cells, in addition to airway epithelial cells, may be involved in converting the parental compound into its active metabolite in the airways.

Inhaled corticosteroids in children with asthma: pharmacologic determinants of safety and efficacy and other clinical considerations

The role of inhaled corticosteroids (ICS) in the treatment of childhood asthma has been well established. An ideal corticosteroid should demonstrate high pulmonary deposition and residency time, in addition to a low systemic bioavailability and rapid systemic clearance. The lung depositions of the ICS have been compared, with beclomethasone (beclometasone)-hydrofluoroalkane (HFA) and ciclesonide showing the highest lung deposition. Lung deposition is influenced by not only the inhalation device and type of propellant (HFA or chlorofluorocarbon), but also by whether the aerosol is a solution or suspension, and the particle size of the respirable fraction. Pulmonary residency time increases when budesonide and des-ciclesonide undergo reversible fatty acid esterification. The bioavailability of the drug depends on the oral bioavailable fraction and the amount absorbed directly from the pulmonary vasculature. The clearance rate of des-ciclesonide is very high (228 L/h), increasing its safety profile by utilizing extra-hepatic clearance mechanisms. Both des-ciclesonide and mometasone have a high protein binding fraction (98-99%). The volume of distribution (Vd) is proportional to the lipophilicity of the drug, with the Vd of fluticasone being 332L compared with 183L for budesonide. Increasing the Vd will also increase the elimination half-life of a drug. The pharmacodynamics of ICS depend on both the receptor binding affinity and the dose-response curve. Among the ICS, fluticasone and mometasone have the highest receptor binding affinity (1800 and 2200, respectively), followed by budesonide at 935 (relative to dexamethasone = 100). Compared with other nonsteroid asthma medications (long-acting beta-agonists, theophylline, and montelukast) ICS have proven superiority in improving lung function, symptom-free days, and inflammatory markers. One study suggests that early intervention with ICS reduces the loss in lung function (forced expiratory volume in 1 second) over 3 years. Whether airway remodeling is reduced or prevented in the long term is unknown. Potential adverse drug effects of ICS include adrenal and growth suppression. While in low-to-medium doses ICS have shown little suppression of the adrenal pituitary axis, in high doses the potential for significant adrenal suppression and adrenal crisis exists. Several longitudinal studies evaluating the effect of ICS on growth have shown a small decrement in growth velocity (approximate 1-2 cm) during the first year of treatment. However, when investigators followed children treated with budesonide for up to 10 years, no change in target adult height was noted. In conclusion, the development of optimal delivery devices for young children, as well as optimizing favorable pharmacokinetic properties of ICS should be priorities for future childhood asthma management.

Comparative in vitro metabolism of 14C-ciclesonide in hepatocytes from the mouse, rat, rabbit, dog, and human

The in vitro metabolism of ciclesonide, a novel inhaled nonhalogenated glucocorticoid for the treatment of asthma, was compared in cryopreserved hepatocytes from mice, rats, rabbits, dogs, and humans. Incubations of C-ciclesonide with individual hepatocyte suspensions revealed similar metabolite profiles in all 5 in vitro systems used. Ciclesonide was rapidly converted to its active metabolite, desisobutyryl-ciclesonide (des-CIC). Des-CIC was then extensively metabolized to pharmacologically inactive metabolites through oxidation and reduction, followed by glucuronidation. A total of 12 groups of metabolites derived from des-CIC were characterized and identified by liquid chromatography/radioactivity monitor/mass spectrometry. Oxidation occurred on both the cyclohexane ring and the steroid moiety. Hippuric acid formation by cleavage of the cyclohexylmethyl moiety of ciclesonide, followed by aromatization of the cyclohexane ring through multiple steps of hydroxylation, dehydration, and conjugation with glycine, was found in rat, rabbit, and human hepatocyte incubations. The results indicated that ciclesonide and its active metabolite, des-CIC, were extensively metabolized in vitro in animal and human hepatocytes and that the metabolite profiles in mouse, rat, rabbit, and dog hepatocytes were similar to the profiles in human hepatocytes.

Evidence-based selection of inhaled corticosteroid for treatment of chronic asthma

Published literature relevant to comparison of various inhaled corticosteroids (ICSs) was reviewed. Marked heterogeneity was found in the reported results. The efficacy and side effects of ICSs depend on their formulation, dosing and device used, and the subjects' age, severity of asthma, and inhaler technique. All these factors have not been included uniformly in most study designs. Notwithstanding this limitation, it appears that fluticasone is generally very effective and safe in low-to-medium doses and may be used for most patients. Budesonide is the only Pregnancy Category B ICSs, all others being Category C, and it is available as nebulizer suspension suitable for use in children over 6 months of age. Budesonide, also available as dry powder inhaler, and beclomethasone, available as metered-dose inhaler, are equal in efficacy, and side effects and may be chosen according to the patient's ability to handle the device. Flunisolide causes fewer side effects but is also relatively less effective. Triamcinolone is generally less effective and causes more side effects than most of the other ICSs. Mometasone may be preferred if once-daily dosing is desired. Ciclesonide has been found highly effective in once-daily dose and without side effects even in high doses. Further studies comparing it with other ICSs over longer periods of use will determine its place in treatment of chronic asthma.

Pharmacokinetic and pharmacodynamic properties of inhaled ciclesonide

Inhaled corticosteroids are recommended first-line therapy for persistent asthma of all severities; however, oropharyngeal and systemic adverse events can be a concern. Inhaled corticosteroids exert their therapeutic and adverse effects by interacting with glucocorticoid receptors within and outside the lungs, respectively. Ciclesonide is a novel inhaled corticosteroid that possesses a unique pharmacokinetic and pharmacodynamic profile. Ciclesonide is inactive itself and converted to its pharmacologically active metabolite, desisobutyryl-ciclesonide, in the target organ, the lungs. Pulmonary activation combined with low oral deposition may minimize oropharyngeal adverse events, and low oral bioavailability, rapid clearance, and high protein binding may reduce systemic exposure. In addition, high pulmonary deposition due to the highly respirable particles, combined with the potential for prolonged lung retention via lipid conjugation, provides for effective therapeutic action.