Once-daily administration of budesonide Turbuhaler was as effective as twice-daily treatment in patients with mild to moderate persistent asthma

In vitro and ex vivo models in inhalation biopharmaceutical research - advances, challenges and future perspectives

Oral inhalation results in pulmonary drug targeting and thereby reduces systemic side effects, making it the preferred means of drug delivery for the treatment of respiratory disorders such as asthma, chronic obstructive pulmonary disease or cystic fibrosis. In addition, the high alveolar surface area, relatively low enzymatic activity and rich blood supply of the distal airspaces offer a promising pathway to the systemic circulation. This is particularly advantageous when a rapid onset of pharmacological action is desired or when the drug is suffering from stability issues or poor biopharmaceutical performance following oral administration. Several cell and tissue-based in vitro and ex vivo models have been developed over the years, with the intention to realistically mimic pulmonary biological barriers. It is the aim of this review to critically discuss the available models regarding their advantages and limitations and to elaborate further which biopharmaceutical questions can and cannot be answered using the existing models.

Therapeutic Mechanisms of Glucocorticoids

Glucocorticoids (GCs) have been used clinically for decades as potent anti-inflammatory and immunosuppressive agents. Nevertheless, their use is severely hampered by the risk of developing side effects and the occurrence of glucocorticoid resistance (GCR). Therefore, efforts to understand the complex mechanisms underlying GC function and GCR are ongoing. The goal is to generate new glucocorticoid receptor (GR) ligands that can dissociate anti-inflammatory from metabolic side effects and/or overcome GCR. In this review paper we discuss recent insights into GR-mediated actions in GCR and novel therapeutic strategies for acute and chronic inflammatory diseases.

In vitro metabolism of beclomethasone dipropionate, budesonide, ciclesonide, and fluticasone propionate in human lung precision-cut tissue slices

Background

The therapeutic effect of inhaled corticosteroids (ICS) may be affected by the metabolism of the drug in the target organ. We investigated the in vitro metabolism of beclomethasone dipropionate (BDP), budesonide (BUD), ciclesonide (CIC), and fluticasone propionate (FP) in human lung precision-cut tissue slices. CIC, a new generation ICS, is hydrolyzed by esterases in the upper and lower airways to its pharmacologically active metabolite desisobutyryl-ciclesonide (des-CIC).

Methods

Lung tissue slices were incubated with BDP, BUD, CIC, and FP (initial target concentration of 25 μM) for 2, 6, and 24 h. Cellular viability was assessed using adenosine 5'-triphosphate content and protein synthesis in lung slices. Metabolites and remaining parent compounds in the tissue samples were analyzed by HPLC with UV detection.

Results

BDP was hydrolyzed to the pharmacologically active metabolite beclomethasone-17-monopropionate (BMP) and, predominantly, to inactive beclomethasone (BOH). CIC was hydrolyzed initially to des-CIC with a slower rate compared to BDP. A distinctly smaller amount (approximately 10-fold less) of fatty acid esters were formed by BMP (and/or BOH) than by BUD or des-CIC. The highest relative amounts of fatty acid esters were detected for BUD. For FP, no metabolites were detected at any time point. The amount of drug-related material in lung tissue (based on initial concentrations) at 24 h was highest for CIC, followed by BUD and FP; the smallest amount was detected for BDP.

Conclusion

The in vitro metabolic pathways of the tested ICS in human lung tissue were differing. While FP was metabolically stable, the majority of BDP was converted to inactive polar metabolites. The formation of fatty acid conjugates was confirmed for BMP (and/or BOH), BUD, and des-CIC.

Once-daily dosing with budesonide/formoterol compared with twice-daily budesonide/formoterol and once-daily budesonide in adults with mild to moderate asthma

Adherence to maintenance therapy is often poor in patients with asthma. Simplifying dosing regimens has the potential to improve both adherence and asthma-related morbidity. In this 12-week, randomized, double-blind, double-dummy, parallel-group study, 617 patients with mild to moderate persistent asthma (mean forced expiratory volume in 1s [FEV1] 78.5% predicted) who were not optimally controlled on inhaled corticosteroids (200-500 microg/day) were randomized to once-daily budesonide/formoterol (80/4.5 microg, 2 inhalations in the evening), twice-daily budesonide/formoterol (80/4.5 microg, 1 inhalation), or a corresponding dose of budesonide once-daily (200 microg, 1 inhalation in the evening). All patients received budesonide (100 microg twice daily) during a 2-week run-in. Changes in mean morning peak expiratory flow (PEF) were similar for od budesonide/formoterol (23.4 l/min) and twice-daily budesonide/formoterol (24.1 l/min), and both were greater than with budesonide (5.5 l/min; both P<0.001). Evening PEF, symptom-free days, reliever-free days, and asthma control days were improved with budesonide/formoterol therapy vs. budesonide (P<0.05 vs. budesonide for all variables). All treatments were well tolerated. Budesonide/formoterol administered once daily in the evening is a convenient treatment regimen that is as effective in improving asthma control as twice-daily dosing in patients with mild to moderate persistent asthma.

Budesonide once versus twice-daily administration: meta-analysis

OBJECTIVES

The aim of this study was to examine the efficacy of budesonide administered once daily compared to twice daily in asthma.

METHODOLOGY

Meta-analysis of randomised controlled trials comparing budesonide administered once versus twice a day that presented data on at least one clinical outcome measure was conducted.

RESULTS

A total of 10 studies, with 1922 children and adults with asthma, met the inclusion criteria. These studies were performed predominantly with mild to moderate asthmatic patients, using doses of budesonide ranging from 200 to 800 microg per day. There was no significant difference between daily dosing once or twice for all the clinical outcome variables, including withdrawals due to asthma, for which the odds ratio was 1.0 (95% confidence interval, 0.65-1.52).

CONCLUSIONS

In mild to moderate asthma a once-daily budesonide regimen has a similar efficacy to a twice-daily regimen in doses up to 800 microg per day. A once-daily regimen has potential advantages in terms of patient compliance and satisfaction, when used in clinical practice.

Once-daily inhaled budesonide for the treatment of asthma: clinical evidence and pharmacokinetic explanation

BACKGROUND

Budesonide, a widely used inhaled corticosteroid (ICS) with a favorable therapeutic ratio, is available via a dry powder inhaler (Pulmicort Turbuhaler) and as a suspension for nebulization (Pulmicort Respules).

METHODS

MEDLINE and an AstraZeneca database were searched to identify relevant controlled clinical trials published between 1986 and 2002 using the key words budesonide OR inhaled corticosteroid, AND once daily.

RESULTS

Thirty-four controlled clinical studies involving once-daily administration of budesonide to asthmatic patients were identified. Excluding long-term studies, this review presents data from 23 controlled studies for 4466 adults or adolescents and 1532 children with asthma and demonstrates efficacy of budesonide in both corticosteroid-naïve patients and patients previously treated with ICS. Once-daily administration of budesonide achieves clinical efficacy comparable with that of twice-daily regimens in patients with mild-to-moderate asthma and is equally effective when given in the morning or evening. Once-daily administration simplifies treatment regimens and may improve patient compliance. The tolerability profiles of budesonide once-daily via Turbuhaler or as budesonide inhalation suspension are good and comparable with those for twice-daily dosing.

CONCLUSIONS

Once-daily budesonide is effective and well tolerated as initial treatment for adults and children with mild asthma and as maintenance therapy in patients with more severe asthma once asthma control has been achieved.

Once-daily inhaled corticosteroids for the treatment of asthma

PURPOSE OF REVIEW

Inhaled corticosteroids (ICS) are the mainstay of asthma therapy. Although compliance to this type of medication is often suboptimal and once-daily dosing can help to improve adherence to the treatment, the clinical implications of such a mode of administration should be determined.

RECENT FINDINGS

This review summarizes the recent studies on comparative efficacy of once-versus twice-daily administration of ICS, in light of previous reports.

SUMMARY

Although twice-daily administration of ICS is often better to optimize asthma parameters, in many patients, asthma can be sufficiently controlled by a once-daily regimen of most ICS. An increased frequency of dosing seems preferable if asthma becomes uncontrolled or is severe, although this requires further study. A therapeutic trial should, however, be done to ensure that asthma control is adequate. Comparative long-term effects of such a strategy on inflammatory and remodeling parameters remain to be determined, as does the proportion of patients who can adequately control their asthma with once-daily administration of the various ICS available.

The role of intracellular esterification in budesonide once-daily dosing and airway selectivity

BACKGROUND

Since their introduction in the 1970s, inhaled corticosteroids (ICSs) have been used to control airway inflammation associated with asthma. Budesonide is one of the ICSs recommended as first-line therapy for mild to moderate persistent asthma.

OBJECTIVE

This article describes the esterification of budesonide and how it results in prolonged, location-specific retention of drug in the airways, allowing once-daily dosing.

RESULTS

Studies conducted over the past decade have shown that budesonide forms reversible fatty acid esters within the cells of airway tissue, resulting in the formation of an intracellular depot pool of inactive drug. As the intracellular concentration of free budesonide decreases, these budesonide esters are hydrolyzed back to their active state. This process increases budesonide's retention in the airways, prolongs its duration of action, and lowers the risk of systemic effects.

CONCLUSIONS

By extending budesonide's local anti-inflammatory effect and increasing its airway selectivity, the esterification process appears to contribute to the drug's efficacy, particularly during once-daily administration. Reducing the number of required daily inhalations may increase patient compliance with asthma therapy, although this remains to be evaluated.

Comparative efficacy of once-daily therapy with inhaled corticosteroid, leukotriene antagonist or sustained-release theophylline in patients with mild persistent asthma

The purpose of this study was to compare the efficacy and safety of the inhaled budesonide, sustained-release theophylline and montelukast, a leukotriene receptor antagonist, in patients with mild persistent asthma. In this single-center, randomized, parallel-group study that not designed blindly and placebo-controlled manner, 74 patients with mild persistent asthma were treated with either inhaled budesonide 400 microg once daily, oral montelukast 10 mg once daily, or sustained-release theophylline 400 mg once daily for 3 months. In all three treatment groups, improvements were attained in overall asthma control. Asthma symptom scores and supplemental beta2-agonist use were quite the same in all three treatment groups (P>0.05). Although inhaled budesonide group resulted in significantly greater improvements compared with the other two groups in the lung functions (P<0.05), the changes in FEV1 and PEF are within the baseline variability and there was no statistically significant difference among the groups when analyzed by treatment month (P>0.05). Exacerbations of asthma were experienced by 16% of the patients in the montekulast group, by 12.5% of the patients in the theophylline group, and by none of the patients in the budesonide group. The adverse event in each of the three groups was 12%, 16% and 16.7%, respectively. It is concluded that the most important clinical parameters do not point that one of the treatments is more effective than others. Treatment with inhaled corticosteroid is preferred, but sustained-release theophylline and leukotriene antagonists are alternative controller medications in mild persistent asthma.