Plasma concentrations of fluticasone propionate and budesonide following inhalation: effect of induced bronchoconstriction

The Pharmacokinetics of Inhaled Drugs

The pharmacokinetic (PK) profile of a drug after inhalation may differ quite markedly from that seen after dosing by other routes of administration. Drugs may be administered to the lung to elicit a local action or as a portal for systemic delivery of the drug to its site of action elsewhere in the body. Some knowledge of PK is important for both locally- and systemically-acting drugs. For a systemically-acting drug, the plasma concentration-time profile shares some similarities with drug given by the oral or intravenous routes, since the plasma concentrations (after the distribution phase) will be in equilibrium with concentrations at the site of action. For a locally-acting drug, however, the plasma concentrations reflect its fate after it has been absorbed and removed from the airways, and not what is available to its site of action in the lung. Consequently, those typical PK parameters which are determined from plasma concentration measurements, e.g., area under the curve (AUC), Cmax, tmax and post-peak t1/2 may provide information on the deposition and absorption of drugs from the lung; however, the information from these parameters becomes more complicated to decipher for those drugs which are locally-acting in the lung. Additionally, the plasma concentration profile for both locally- and systemically-acting drugs will not only reflect drug absorbed from the lung but also that absorbed from the gastrointestinal (GI) tract from the portion of the dose which is swallowed. This absorption from the GI tract adds a further complication to the interpretation of plasma concentrations, particularly for locally-acting drugs. The influence of physiological and pathological factors needs to be considered in the absorption of some inhaled drugs. The absorption of some hydrophilic drugs is influenced by the inspiratory maneuver used during initial inhalation of the drug, and at later times after deposition. Similarly, the effects of smoking have been shown to increase lung permeability and increase the absorption of certain hydrophilic drugs. The effects of different disease states of the lung have less defined influences on absorption into the systemic circulation.

Serum Inhaled Corticosteroid Detection for Monitoring Adherence in Severe Asthma

BACKGROUND

Daily inhaled corticosteroids (ICSs) are fundamental to asthma management, but adherence is low.

OBJECTIVES

To investigate (1) whether LC-MS/MS could be used to detect ICSs in serum and (2) whether serum levels related to markers of disease severity.

METHODS

We collected blood samples over an 8-hour period from patients with severe asthma prescribed at least 1000 μg daily of beclomethasone dipropionate equivalent. Following baseline sampling, patients were observed taking their usual morning dose. Subsequent blood samples were obtained 1, 2, 4, and 8 hours postinhalation and analyzed by LC-MS/MS. Correlations between serum ICS levels and severity markers were investigated.

RESULTS

A total of 60 patients were recruited (41 females; 39 prescribed maintenance prednisolone; mean age, 49 ± 12 years; FEV₁, 63 ± 20 %predicted). Eight hours postinhalation, all patients using budesonide (n = 10) and beclomethasone dipropionate (15), and all but 1 using fluticasone propionate (28), had detectable serum drug levels. Fluticasone furorate was detected in 2 patients (of 4), ciclesonide in none (of 7). Low adherence by repeat prescription records (<80%) was identified in 43%. Blood ICS levels correlated negatively with exacerbation rate, and (for fluticasone propionate only) positively with FEV₁ %predicted.

CONCLUSIONS

Commonly used ICSs can be reliably detected in the blood at least 8 hours after dosing, and could therefore be used as a measure of adherence in severe asthma. Higher exacerbation rates and poorer lung function (for fluticasone propionate) were associated with lower blood levels.

Combined in Vitro-in Silico Approach to Predict Deposition and Pharmacokinetics of Budesonide Dry Powder Inhalers

PURPOSE

A combined in vitro - in silico methodology was designed to estimate pharmacokinetics of budesonide delivered via dry powder inhaler.

METHODS

Particle size distributions from three budesonide DPIs, measured with a Next Generation Impactor and Alberta Idealized Throat, were input into a lung deposition model to predict regional deposition. Subsequent systemic exposure was estimated using a pharmacokinetic model that incorporated Nernst-Brunner dissolution in the conducting airways to predict the net influence of dissolution, mucociliary clearance, and absorption.

RESULTS

DPIs demonstrated significant in vitro differences in deposition, resulting in large differences in simulated regional deposition in the central conducting airways and the alveolar region. Similar but low deposition in the small conducting airways was observed with each DPI. Pharmacokinetic predictions showed good agreement with in vivo data from the literature. Peak systemic concentration was tied primarily to the alveolar dose, while the area under the curve was more dependent on the total lung dose. Tracheobronchial deposition was poorly correlated with pharmacokinetic data.

CONCLUSIONS

Combination of realistic in vitro experiments, lung deposition modeling, and pharmacokinetic modeling was shown to provide reasonable estimation of in vivo systemic exposure from DPIs. Such combined approaches are useful in the development of orally inhaled drug products.

A Randomized Comparison of the Pharmacokinetics and Bioavailability of Fluticasone Propionate Delivered via Xhance Exhalation Delivery System Versus Flonase Nasal Spray and Flovent HFA Inhalational Aerosol

PURPOSE

The exhalation delivery system with fluticasone propionate (Xhance®) has been shown to deliver drug substantially more broadly in the nasal cavity (particularly into superior/posterior regions), with less off-target loss of drug to drip-out and swallowing, than conventional nasal sprays. This open-label study evaluated the systemic bioavailability of Xhance® by comparing the pharmacokinetic (PK) properties of a single dose of fluticasone from 3 products administering the drug using 3 different devices: Xhance®, Flonase® (fluticasone propionate inhalational nasal spray), and Flovent® HFA (fluticasone propionate inhalational aerosol).

METHODS

This open-label study was conducted in 2 parts. Study part 1 compared systemic exposure with a single dose of Xhance® 186 or 372 μg versus Flonase® 400 μg (3-way, 3-treatment, 3-sequence, randomized crossover in healthy subjects; n = 90). A separate study, part 2, under the same umbrella protocol, compared systemic exposure with Xhance® 372 μg versus Flovent® HFA 440 μg (2-way, 2-treatment, 2-sequence, randomized crossover in patients with mild to moderate asthma; n = 30).

FINDINGS

With Xhance® 186 μg, the geometric least squares mean (LSM) C_max was higher than with Flonase® 400 μg (16.02 vs 11.66 pg/mL, respectively; geometric mean ratio [GMR], 137.42%) and the geometric LSM AUC_0-∞ values were similar (97.30 vs 99.61 pg · h/mL; GMR, 97.78%). With Xhance® 372 μg, the geometric LSM C_max and AUC_0-∞ were higher than with Flonase® 400 μg (C_max, 23.50 vs 11.66 pg/mL [GMR, 201.53%]; AUC_0-∞, 146.61 vs 99.61 pg · h/mL [GMR, 147.19%]). In part 2, the geometric LSM C_max and AUC_0-∞ values were lower with Xhance® 372 μg than with Flovent® HFA 440 μg (C_max, 25.28 vs 40.02 pg/mL [GMR, 63.18%]; AUC_0-∞, 205.78 vs 415.16 pg · h/mL [GMR, 49.57%]).

IMPLICATIONS

Similar intranasal doses of Xhance® (372 μg) and Flonase® (400 μg) are clearly not bioequivalent. Systemic exposure is very low with all products. Systemic exposure is higher with Xhance® than with Flonase® and substantially lower than with Flovent® HFA 440 μg and, based on dose normalization, Flovent® HFA 220 μg. ClincalTrials.gov identifier: NCT02266927.

A compartment-quasi-3D multiscale approach for drug absorption, transport, and retention in the human lungs

Most current models used for modeling the pulmonary drug absorption, transport, and retention are 0D compartmental models where the airways are generally split into the airways and alveolar sections. Such block models deliver low fidelity solutions and the spatial lung drug concentrations cannot be obtained. Other approaches use high fidelity CFD models with limited capabilities due to their exorbitant computational cost. Recently, we presented a novel, fast-running and robust quasi-3D (Q3D) model for modeling the pulmonary airflow. This Q3D method preserved the 3D lung geometry, delivered extremely accurate solutions, and was 25 000 times faster in comparison to the CFD methods. In this paper, we present a Q3D-compartment multiscale combination to model the pulmonary drug absorption, transport, and retention. The initial deposition is obtained from CFD simulations. The lung absorption compartment model of Yu and Rosania is adapted to this multiscale format. The lung is modeled in the Q3D format till the eighth airway generation. The remainder of the lung along with the systemic circulation and elimination processes was modeled using compartments. The Q3D model is further adapted, by allowing for various heterogeneous annular lung layers. This allows us to model the drug transport across the layers and along the lung. Using this multiscale model, the spatiotemporal drug concentrations in the different lung layers and the temporal concentration in the plasma are obtained. The concentration profile in the plasma was found to be better aligned with the experimental findings in comparison with compartmental model for the standard test cases. Thus, this multiscale model can be used to optimize the target-specific drug delivery and increase the localized bioavailability, thereby facilitating applications from the bench to bedside for various patient/lung-disease variations.

Influence of respiratory tract disease and mode of inhalation on detectability of budesonide in equine urine and plasma

OBJECTIVE To evaluate the influence of respiratory tract disease (ie, recurrent airway obstruction [RAO]) and mode of inhalation on detectability of inhaled budesonide in equine plasma and urine samples. ANIMALS 16 horses (8 healthy control horses and 8 horses affected by RAO, as determined by results of clinical examination, blood gas analysis, bronchoscopy, and cytologic examination of bronchoalveolar lavage fluid). PROCEDURES 4 horses of each group inhaled budesonide (3 μg/kg) twice daily for 10 days while at rest, and the remaining 4 horses of each group inhaled budesonide during lunging exercise. Plasma and urine samples were obtained 4 to 96 hours after inhalation and evaluated for budesonide and, in urine samples, the metabolites 6β-hydroxybudesonide and 16α-hydroxyprednisolone. RESULTS Detected concentrations of budesonide were significantly higher at all time points for RAO-affected horses, compared with concentrations for the control horses. All samples of RAO-affected horses contained budesonide concentrations above the limit of detection at 96 hours after inhalation, whereas this was found for only 2 control horses. Detected concentrations of budesonide were higher, but not significantly so, at all time points in horses that inhaled budesonide during exercise, compared with concentrations for inhalation at rest. CONCLUSIONS AND CLINICAL RELEVANCE Results of this study indicated that the time interval between inhalation of a glucocorticoid and participation in sporting events should be increased when inhalation treatment is administered during exercise to horses affected by respiratory tract disease.

Maternal inhaled fluticasone propionate intake during pregnancy is detected in neonatal cord blood

BACKGROUND

Despite recommendations to use inhaled corticosteroids as treatment to control asthma during pregnancy, it is unknown whether inhaled fluticasone propionate (FP) reaches the fetus. Results & methodology: We collected maternal blood on the morning following delivery. FP was detected by ultra-performance LC-MS/MS (UPLC-MS/MS) in 9/17 asthmatic women using FP. Delay between last FP inhalation and maternal blood sampling ranged between 3 and 33 h and FP was detected in a range of 1.572-46.440 pg/ml. Among the nine offspring of these FP users, FP was detected in five cord blood samples. Delay between last predelivery FP inhalation and cord blood sampling ranged from 4 to 20 h and FP was detected in a range of 0.423-4.510 pg/ml.

CONCLUSION

Our findings demonstrate placental passage of inhaled FP.

A Systematic Analysis of the Sensitivity of Plasma Pharmacokinetics to Detect Differences in the Pulmonary Performance of Inhaled Fluticasone Propionate Products Using a Model-Based Simulation Approach

The role of plasma pharmacokinetics (PK) for assessing bioequivalence at the target site, the lung, for orally inhaled drugs remains unclear. A validated semi-mechanistic model, considering the presence of mucociliary clearance in central lung regions, was expanded for quantifying the sensitivity of PK studies in detecting differences in the pulmonary performance (total lung deposition, central-to-peripheral lung deposition ratio, and pulmonary dissolution characteristics) between test (T) and reference (R) inhaled fluticasone propionate (FP) products. PK bioequivalence trials for inhaled FP were simulated based on this PK model for a varying number of subjects and T products. The statistical power to conclude bioequivalence when T and R products are identical was demonstrated to be 90% for approximately 50 subjects. Furthermore, the simulations demonstrated that PK metrics (area under the concentration time curve (AUC) and C max) are capable of detecting differences between T and R formulations of inhaled FP products when the products differ by more than 20%, 30%, and 25% for total lung deposition, central-to-peripheral lung deposition ratio, and pulmonary dissolution characteristics, respectively. These results were derived using a rather conservative risk assessment approach with an error rate of <10%. The simulations thus indicated that PK studies might be a viable alternative to clinical studies comparing pulmonary efficacy biomarkers for slowly dissolving inhaled drugs. PK trials for pulmonary efficacy equivalence testing should be complemented by in vitro studies to avoid false positive bioequivalence assessments that are theoretically possible for some specific scenarios. Moreover, a user-friendly web application for simulating such PK equivalence trials with inhaled FP is provided.

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 choice of inhalation device: A medical act]

Inhaled treatments are essential for respiratory diseases management, including COPD and asthma. Optimal control of the disease largely depends on patient's compliance and proper use of these treatments. Different types of ready-to-use inhaler devices are available: metered dose inhaler, dry powder inhaler or soft mist inhaler. Each of these devices presents specific characteristics and constraints that have to be evaluated and taken into account before prescription. In order to optimize adherence and treatment efficacy, the choice of inhaler device should depend on the specific needs, abilities and preferences of each patient and a specific education to treatment should be provided. Inhaled treatments, even containing the same drug, have different technical constraints and are thus not easily interchangeable. Their substitution without prior medical consent and without proper training can lead to errors in taking treatment, treatment failures and increased health care consumption. In France, substitution by the pharmacist is not authorized. While patient education must be carried out in collaboration with all health professionals, it is preferable that the choice of inhaler device remains the responsibility of the physician.

Prehospital use of inhaled corticosteroids and point prevalence of pneumonia at the time of hospital admission: secondary analysis of a multicenter cohort study

OBJECTIVE

To address clinical concern regarding the use of inhaled corticosteroids (ICSs) and the risk for pneumonia, particularly among patients with chronic obstructive pulmonary disease (COPD) and asthma.

PATIENTS AND METHODS

A multicentered prospective cohort of patients admitted to the hospital from March 1, 2009, through August 31, 2009, with pneumonia or another risk factor for acute respiratory distress syndrome was analyzed to determine the risk for pneumonia requiring hospitalization among patients taking ICSs. The adjusted risk (odds ratio [OR]) for developing pneumonia because of ICSs was determined in a multiple logistic regression model.

RESULTS

Of the 5584 patients in the cohort, 495 (9%) were taking ICSs and 1234 (22%) had pneumonia requiring hospitalization. In univariate analyses, pneumonia occurred in 222 (45%) of the patients on ICSs vs 1012 (20%) in those who were not (OR, 3.28; 95% CI, 2.71-3.96; P<.001). After adjusting in the logistic regression model, prehospital ICS use was not significantly associated with pneumonia in the whole cohort (OR, 1.20; 95% CI, 0.93-1.53; P=.162), among the subset of 589 patients with COPD (OR, 1.40; 95% CI, 0.95-2.09; P=.093), among the 440 patients with asthma (OR, 1.07; 95% CI, 0.61-1.87; P=.81), nor among the remaining 4629 patients without COPD or asthma (OR, 1.32; 95% CI, 0.88-1.97; P=.179).

CONCLUSION

When adjusted for multiple confounding variables, ICS use was not substantially associated with an increased risk for pneumonia requiring admission in our cohort.

Assessment of endogenous, oral and inhaled steroid cross-reactivity in the Roche cortisol immunoassay

BACKGROUND

Inhaled steroids are widely used for the treatment of asthma. Concerns over adrenal suppression when used at high doses or in combination with drugs such as ritonavir exist, requiring the measurement of serum cortisol. Herein, we investigate the cross-reactivity of the inhaled steroids betamethasone, fluticasone and beclomethasone in the Roche cortisol immunoassay, in addition to five other steroids.

METHODS

Five replicates were produced from a serum pool for each of the eight steroids at a final concentration of 0.1 and 1 µg/mL. Each steroid was dissolved in 50% methanol, with 50% methanol of the same volume added to the control sample. The cross-reactivity of each steroid in the cortisol assay was calculated.

RESULTS

There was no statistically or clinically significant cross-reactivity in the measurement of cortisol when fluticasone, beclomethasone or betamethasone were spiked at 0.1 and 1.0 µg/mL, except for beclomethasone at a concentration of 1 µg/mL (1490 nmol/L) with a cross-reactivity of 1.6%, which is unlikely to be clinically significant. At both steroid concentrations investigated, prednisolone, 17-hydroxyprogesterone and 11-deoxycortisol exhibited statistically significant cross-reactivities that were greater than the least significant change of the assay (13.1%), whereas dexamethasone and metyrapone did not. Mean inter-assay precision was 1.5% (405-1586 nmol/L).

CONCLUSION

The cross-reactivity of the inhaled steroids; betamethasone, fluticasone and beclomethasone in the Roche cortisol immunoassay are unlikely to be clinically significant at the concentrations found in patients on therapeutic doses. This will enable confident assessment of adrenal status in patients at risk of adrenal suppression.

A pharmacokinetic simulation tool for inhaled corticosteroids

The pharmacokinetic (PK) behavior of inhaled drugs is more complicated than that of other forms of administration. In particular, the effects of certain physiological (mucociliary clearance and differences in membrane properties in central and peripheral (C/P) areas of the lung), formulation (as it relates to drug deposition and particle dissolution rate), and patient-related factors (lung function; effects on C/P deposition ratio) affect the systemic PKs of inhaled drugs. The objectives of this project were (1) to describe a compartmental model that adequately describes the fate of inhaled corticosteroids (ICS) after administration while incorporating variability between and within subjects and (2) based upon the model, to provide a freely available tool for simulation of PK trials after ICS administration. This compartment model allows for mucociliary removal of undissolved particles from the lung, distinguishes between central and peripheral regions of the lung, and models drug entering the systemic circulation via the lung and the gastrointestinal tract. The PK simulation tool is provided as an extension package to the statistical software R ('ICSpkTS'). It allows simulation of PK trials for hypothetical ICS and of four commercially available ICS (budesonide, flunisolide, fluticasone propionate, and triamcinolone acetonide) in a parallel study design. Simulated PK data and parameters agreed well with literature data for all four ICS. The ICSpkTS package is especially suitable to explore the effect of changes in model parameters on PK behavior and can be easily adjusted for other inhaled drugs.

[Treatment of distal airways involvement in COPD]

INTRODUCTION

The current pharmacological treatment of COPD provides only partial beneficial effects on symptoms, exercise tolerance, frequency of exacerbations and quality of life. This could be related to poor targeting of the distal airways by current treatments, yet these airways are particularly involved in airflow obstruction and its consequences such as hyperinflation.

BACKGROUND

Many treatments used in COPD could have effects on distal airways, including bronchodilators, corticosteroids, mucolytics and antibiotics. However, these possible effects remain poorly understood.

VIEWPOINTS

New treatments targeting more specifically the mechanisms of inflammation, oxidative stress and tissue remodeling that characterize COPD, could prove useful in its management, but most are still only in the early stages of their development. Advances could also come from improvements in inhalation devices, delivering more of the medication to the distal airways.

CONCLUSIONS

Improvement in the management of COPD could come from progress in terms of both molecules and their mode of administration.

Budesonide and formoterol in a single pressurized metered-dose inhaler for treatment of COPD

Budesonide/formoterol in two dosage strengths (80/4.5 µg and 160/4.5 µg), each administered as two inhalations twice daily, was previously developed as a fixed-dose inhaled corticosteroid/long-acting β-agonist combination in a pressurized metered-dose inhaler for use in asthma. More recent double-blind, randomized controlled trials of 6 and 12 months duration (referred to, respectively, as SHINE and SUN) have demonstrated the efficacy and safety of the higher-dose formulation in patients with severe and very severe chronic obstructive pulmonary disease. Specifically, budesonide/formoterol 160/4.5 µg (two inhalations twice daily) has demonstrated additive benefits over one or the other of its monocomponents with respect to improvements in morning predose and 1-h postdose lung function, as well as greater improvements in respiratory symptoms, health status and rescue medication use, and greater reductions in exacerbations of chronic obstructive pulmonary disease than placebo. It also has a satisfactory safety profile and has not been shown to increase the risk of pneumonia.

Inhaled fluticasone and the hormonal and inflammatory response to brief exercise

PURPOSE

Inhaled corticosteroids (ICS) improve symptoms in lung diseases, such as asthma. Initial data suggest that the effects of ICS remain localized in the lung; however, recent studies demonstrate alteration to the peripheral immune system in patients with asthma. We sought to evaluate the effect of ICS on peripheral immune mediators and hypothalamic-pituitary-adrenal axis and their response to exercise in healthy men.

METHODS

Eleven healthy males (18-30 yr old) were placed on 2 wk of fluticasone proprionate (440 μg) twice daily. A 30-min bout of exercise was performed on a cycle ergometer at approximately 70% of peak work rate before and after the start of ICS. Blood was sampled before and after exercise. Cytokines and hypothalamic-pituitary-adrenal axis mediators were measured by ELISA, and fluticasone was measured by liquid chromatography/tandem mass spectrometry.

RESULTS

After ICS treatment, cortisol and adrenocorticotropin were decreased, and a blunted exercise response was observed for cortisol, adrenocorticotropin, and growth hormone. Peripheral leukocytes and neutrophils were significantly increased in response to exercise in both the untreated and the ICS-treated conditions and at baseline after ICS treatment. Interleukin-6 was elevated with ICS treatment, but the exercise response was blunted. Circulating median fluticasone levels were 0.15 ng·mL(-1) and were increased to 0.20 ng·mL(-1) in response to exercise.

CONCLUSIONS

Exercise revealed deficits in growth hormone production after ICS treatment not identified by static markers. Neutrophils were shown to be surrogate markers of the systemic effect of ICS. Exercise significantly increased circulating levels of fluticasone. Exercise challenge tests can be used to assess the physiological effect of exogenous corticosteroids.

Inhaled corticosteroids and risk of pneumonia: evidence for and against the proposed association

Inhaled corticosteroids (ICS) are commonly used in the treatment of chronic obstructive pulmonary disease. Recent large prospective trials have reported an increased incidence of pneumonia in patients treated with ICS. Despite this, the link between ICS and pneumonia remains controversial. In this review, pro and con arguments for the association between ICS and increased pneumonia risk are discussed, drawing on evidence from experimental and clinical research.

The bioavailability and airway clearance of the steroid component of budesonide/formoterol and salmeterol/fluticasone after inhaled administration in patients with COPD and healthy subjects: a randomized controlled trial

Background

Airway absorption and bioavailability of inhaled corticosteroids (ICSs) may be influenced by differences in pharmacokinetic properties such as lipophilicity and patient characteristics such as lung function. This study aimed to further investigate and clarify the distribution of budesonide and fluticasone in patients with severe chronic obstructive pulmonary disease (COPD) by measuring the systemic availability and sputum concentration of budesonide and fluticasone, administered via combination inhalers with the respective long-acting β₂-agonists, formoterol and salmeterol.

Methods

This was a randomized, double-blind, double-dummy, two-way crossover, multicenter study. Following a run-in period, 28 patients with severe COPD (mean age 65 years, mean forced expiratory volume in 1 second [FEV₁] 37.5% predicted normal) and 27 healthy subjects (mean age 31 years, FEV₁ 103.3% predicted normal) received two single-dose treatments of budesonide/formoterol (400/12 μg) and salmeterol/fluticasone (50/500 μg), separated by a 4–14-day washout period. ICS concentrations were measured over 10 hours post-inhalation in plasma in all subjects, and over 6 hours in spontaneously expectorated sputum in COPD patients. The primary end point was the area under the curve (AUC) of budesonide and fluticasone plasma concentrations in COPD patients relative to healthy subjects.

Results

Mean plasma AUC values were lower in COPD patients versus healthy subjects for budesonide (3.07 μM·hr versus 6.21 μM·hr) and fluticasone (0.84 μM·hr versus 1.50 μM·hr), and the dose-adjusted AUC (geometric mean) ratios in healthy subjects and patients with severe COPD for plasma budesonide and fluticasone were similar (2.02 versus 1.80; primary end point). In COPD patients, the T_max and the mean residence time in the systemic circulation were shorter for budesonide versus fluticasone (15.5 min versus 50.8 min and 4.41 hrs versus 12.78 hrs, respectively) and C_max was higher (1.08 μM versus 0.09 μM). The amount of expectorated fluticasone (percentage of estimated lung-deposited dose) in sputum over 6 hours was significantly higher versus budesonide (ratio 5.21; p = 0.006). Both treatments were well tolerated.

Conclusion

The relative systemic availabilities of budesonide and fluticasone between patients with severe COPD and healthy subjects were similar. In patients with COPD, a larger fraction of fluticasone was expectorated in the sputum as compared with budesonide.

Trial registration

Trial registration number NCT00379028

Budesonide and the risk of pneumonia: a meta-analysis of individual patient data

BACKGROUND

Concern is continuing about increased risk of pneumonia in patients with chronic obstructive pulmonary disease (COPD) who use inhaled corticosteroids. We aimed to establish the effects of inhaled budesonide on the risk of pneumonia in such patients.

METHODS

We pooled patient data from seven large clinical trials of inhaled budesonide (320-1280 mug/day), with or without formoterol, versus control regimen (placebo or formoterol alone) in patients with stable COPD and at least 6 months of follow-up. The primary analysis compared treatment groups for the risk of pneumonia as an adverse event or serious adverse event during the trial or within 15 days of the trial end. Cox proportional hazards regression was used to analyse the data on an intention-to-treat basis. Data were adjusted for patients' age, sex, smoking status, body-mass index, and postbronchodilator percent of predicted forced expiratory volume in 1 s (FEV(1)).

FINDINGS

We analysed data from 7042 patients, of whom 3801 were on inhaled budesonide and 3241 were on control treatment, with 5212 patient-years of exposure to treatment. We recorded no significant difference between treatment groups for the occurrence of pneumonia as an adverse event (3% [n=122 patients] vs 3% [n=103]; adjusted hazard ratio 1.05, 95% CI 0.81-1.37) or a serious adverse event (1% [n=53] vs 2% [n=50]; 0.92, 0.62-1.35), or for time to pneumonia as an adverse event (log-rank test 0.94) or a serious adverse event (0.61). Increasing age and decreasing percent of predicted FEV(1) were the only two variables that were significantly associated with occurrence of pneumonia as an adverse event or a serious adverse event.

INTERPRETATION

Budesonide treatment for 12 months does not increase the risk of pneumonia in patients with COPD during that time and therefore is safe for clinical use in such patients.

FUNDING

Michael Smith Foundation for Health Research.

Do airway clearance mechanisms influence the local and systemic effects of inhaled corticosteroids?

The role of airway clearance in inhaled drug therapy is complex. Disease-induced bronchoconstriction results in a central drug-deposition pattern where mucociliary clearance is most efficient. When drug-induced bronchodilation is achieved, deposition and uptake becomes more peripheral, and because there is less mucociliary clearance in the periphery, this will lead to an unintentional increase in lung exposure and enhance the risk of systemic side effects. In addition, mucociliary clearance is pathologically reduced in both asthma and chronic obstructive pulmonary disease. Among inhaled corticosteroids, rate of dissolution and lung uptake differs considerably. For the slowly dissolving, lipophilic steroids, the contribution of mucociliary clearance to these findings appears significant, and variability in lung and systemic exposure resulting from variable mucociliary function appears to be amplified. In addition, dose optimisation of non-stable asthma becomes more complex. The present review highlights the impact of mucociliary clearance on inhaled corticosteroid disposition and identifies critical areas where more research is needed.