Rationale for once-daily therapy in asthma: compliance issues

Adherence to treatment by patients with asthma or COPD: comparison between inhaled drugs and transdermal patch

An Internet-based questionnaire study involving patients with asthma and chronic obstructive pulmonary disease (COPD) and parents of children with asthma was conducted to evaluate adherence to treatment, and convenience of inhalation and transdermal formulations. Valid responses were obtained from 1470 patients. Among asthmatic patients, the percentage of those who selected "taking as prescribed" was 52.7% for inhalant users and 83.2% for transdermal users. Among patients with COPD, the corresponding values were 54.7% and 86.6%. There was a significant difference (p<0.01) in treatment compliance between inhalation and transdermal formulations in both groups. The most common reason for poor adherence was "frequency of administration", and 83.2% of the patients preferred a once-daily administration. In addition, patients who had used both types of formulations preferred the transdermal ones. In conclusion, health care professionals should further educate their patients about the importance of treatment with inhalants, since poor adherence to treatment with inhalation formulations significantly hinders achievement of optimal efficacy. In addition, transdermal tulobuterol patch, which is administered once daily as a long-acting, beta(2)-agonist, appeared to be useful for long-term control of both asthma and COPD.

Impact of inhaled corticosteroid-induced oropharyngeal adverse events: results from a meta-analysis

BACKGROUND

Oropharyngeal adverse events associated with inhaled corticosteroid (ICS) use can affect adherence; however, these effects have been studied less extensively than those that occur systemically.

OBJECTIVE

To calculate the risk of ICS-induced oral candidiasis, dysphonia, and pharyngitis among currently available therapies and to determine related effects of dose and device.

METHODS

A computerized search in MEDLINE (January 1966 to June 2004) and EMBASE (January 1974 to June 2004) was conducted using indexed MedDRA terms for oropharyngeal adverse events. Odds ratios (ORs) were used to determine the rate of ICS-induced adverse events based on dose and device.

RESULTS

A total of 23 studies (59 drug arms) were evaluated. Incidence of oral candidiasis (P < or = .001), dysphonia (P < or = .001), and pharyngitis (P < or = .023) increased significantly with dose vs placebo at all dose levels and combined, regardless of device. Overall, the ICS metered-dose inhaler (MDI) device (hydrofluoroalkane formulation, 4 arms; chlorofluorocarbon formulation, 26 arms) was associated with a 5-fold greater risk of oral candidiasis vs MDI placebo (OR, 5.40). In contrast, the ICS dry-powder inhaler (DPI) device had a 3-fold greater risk for oral candidiasis vs DPI placebo (OR, 3.24). A similar trend was observed with regard to dysphonia (ICS MDI: OR, 5.68; ICS DPI: OR, 3.74; both vs. placebo). Both ICS MDI and DPI were associated with an approximately 2-fold greater risk of pharyngitis compared with placebo.

CONCLUSIONS

Currently available inhaled corticosteroids canbe associated with oropharyngeal adverse events. Such events may be reduced by postdose mouth rinsing or use of a spacer.

Airway selectivity: an update of pharmacokinetic factors affecting local and systemic disposition of inhaled steroids

Topical corticosteroids remain the most efficacious single treatment for asthma and rhinitis, despite the emergence of newer drugs in recent years. The antiinflammatory properties of these products, combined with the targeting of formulations and optimization of the intrinsic pharmacokinetic features of the newer corticosteroid molecules has resulted in substantially improved airway selectivity. This review sets out to summarize the pharmacokinetic properties of inhaled corticosteroids that are important for the achievement of high levels of airway selectivity, with additional focus on the use of prodrugs/softdrugs relative to those of conventional corticosteroid molecules, mechanisms (such as esterification) by which retention at the target site is achieved while minimizing systemic exposure, and the role of plasma protein binding.

Effects of mometasone furoate given once daily in the evening on lung function and symptom control in persistent asthma

BACKGROUND

The chronobiology of asthma suggests that, for once-daily dosing, an evening dose may be the most effective treatment paradigm.

OBJECTIVE

To evaluate the efficacy and safety of mometasone furoate dry powder inhaler (MF-DPI) administered once daily in the evening or twice daily in patients with asthma previously maintained on twice-daily regimens of inhaled corticosteroids.

METHODS

In this 12-week, multicenter, placebo-controlled trial, 268 subjects > or =12 years of age with inhaled corticosteroid-dependent asthma and baseline forced expiratory volume in 1 second (FEV(1)) between 50% and 85% of predicted were randomized to receive treatment with MF-DPI 400 mug once daily in the evening, MF-DPI 200 mug twice daily, or placebo. The primary efficacy variable was mean change in FEV(1) from baseline to endpoint. Other lung function measures, asthma symptoms, quality of life, and rescue medication use also were assessed.

RESULTS

At endpoint, mean FEV(1) was significantly improved with both MF-DPI doses compared with placebo (p < 0.001). The 2 active treatment groups were statistically indistinguishable from each other. Secondary efficacy variables, including nocturnal awakenings, asthma worsenings, quality of life, and rescue medication use, were also significantly improved for both MF-DPI treatments compared with placebo. Both dosages were well tolerated; no clinically meaningful changes in laboratory values or vital signs were observed.

CONCLUSIONS

MF-DPI 400 mug once daily in the evening was as effective as MF-DPI 200 mug twice daily in improving pulmonary function, asthma symptoms, and quality of life compared with placebo in subjects previously using twice-daily regimens of an inhaled corticosteroid.

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.

Medication non-adherence in the elderly: how big is the problem?

Adherence to medication is one of the most intriguing and complex behaviours demonstrated by patients. Non-adherence to a therapeutic regimen may result in negative outcomes for patients and may be compounded in populations with multiple morbidities which require multiple drug therapy. Such a population is exemplified by the elderly. However, non-adherence may not be more prevalent in older patients and there is no consensus in the literature that age is a predictor of poor adherence. Indeed, older patients may deliberately choose not to adhere to medication (intentional non-adherence) to avoid adverse effects. Furthermore, many of the studies on adherence lack commonality in terms of how adherence is measured, the definition of an 'older' patient and the range of disease states which have been examined. Adherence may also be affected by access to medications which may be restricted by the use of formularies or insurance programmes. However, non-adherence may represent a greater risk in older people resulting in poor disease control which may be compounded with multiple morbidity and polypharmacy. A range of strategies have been implemented to try and improve adherence in this patient population. The use of forgiving drugs (those which have a prescribed dosage interval that is 50% or less the duration of drug action) may facilitate occasional lapses in drug-taking. Drug holidays (deliberate, supervised non-adherence for a fixed period of time) have been used in Parkinson's disease to reduce adverse effects. Once-daily scheduling of drug administration may offer a pragmatic approach to optimising drug therapy in some patients; this may be supplemented through the use of compliance aids. What is increasingly apparent, however, is that the role of the patient (irrespective of age) is critical in decision-making about medication, together with communication between patients and healthcare professionals. This has been articulated through the concept of concordance which has been described as a therapeutic alliance between the patient and healthcare professional. In addition, interventions employed to improve adherence must be multifaceted, and together with practical approaches (reducing unnecessary drugs and simplifying dosage regimens), the patient perspective must be considered. Good adherence should be seen as a means of achieving a satisfactory therapeutic result and not as an end in itself.

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.

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.

Adherence to asthma therapy in the preschool child

Preschool children's adherence to asthma therapy is often sub-optimal and can result in decreased quality of life for children and parents, as well as an increased risk for dangerous asthma exacerbations. Asthma management for the preschool child presents some unique challenges to adherence to therapy, including the child's limited ability to communicate, multiple caregivers responsible for medications, and parental concerns about medications. Parent beliefs, characteristics of the regimen, and family functioning have been associated with adherence levels. Understanding and improving adherence to asthma therapy for the preschool child will necessarily require addressing these age-specific concerns.

Misunderstanding of asthma controller medications: association with nonadherence

OBJECTIVE

Nonadherence to regular inhaled anti-inflammatory medication use is a frequent contributor to poor control of persistent asthma and may result from misunderstanding of the preventive role of such medications. This study's aims are to 1) test the hypothesis that misunderstanding is associated with decreased adherence to its daily use and 2) identify factors associated with increased risk of misunderstanding.

STUDY DESIGN

A sample of parents of children with asthma insured by Medicaid and enrolled in managed care programs in Northern California, Washington, and Massachusetts were interviewed by telephone. This analysis focused on the subset that reported having an inhaled anti-inflammatory medication and whose medication use and symptom frequency in the 2 weeks before the interview suggested persistent asthma. Misunderstanding of the role of inhaled anti-inflammatory medication was defined as identifying it as being for treatment of symptoms after they begin and not for prevention of symptoms before they start.

RESULTS

A total of 1663 parents of children with asthma (63% response rate) were interviewed. Of those, 571 subjects (34%) reported use of an inhaled anti-inflammatory medication and met our criteria for persistent asthma. Among those with persistent asthma, 23% (131 parents) misunderstood the role of their child's inhaled anti-inflammatory. Misunderstanding of inhaled anti-inflammatory medication was associated with decreased adherence to its daily use (odds ratio [OR] 0.18, 95% confidence interval [CI], 0.11-0.29). The risk for misunderstanding was lower if the patient had seen a specialist (OR 0.42, 95% CI, 0.24-0.75) or had graduated high school (OR=0.54, 95% CI, 0.34-0.84).

CONCLUSION

Misunderstanding of the role of inhaled anti-inflammatory medication is associated with reduced adherence to its daily use.

Budesonide fatty-acid esterification: a novel mechanism prolonging binding to airway tissue. Review of available data

AIMS

Evidence is accumulating that budesonide (BUD) forms intracellular esters in airways. which may affect both duration of action and therapeutic ratio of this drug. The aim of the present paper is to review the preclinical and human experimental evidence supporting the esterification of BUD, and to discuss the clinical implications this may have on asthma and rhinitis treatment.

RESULTS

After inhalation, intact BUD binds primarily to available steroid receptors, and mainly excess (unbound) BUD is esterified. Esterification of BUD is a rapid process: within 20 minutes of inhalation in the rat of radiolabeled BUD, approximately 80% of radioactivity within the trachea and main bronchi was associated with BUD esters, primarily BUD oleate. After 4 hours, the proportion of BUD esters/total cellular BUD was typically 40 to 50% for lung, 70 to 90% for trachea, and only 10 to 15% for peripheral muscle. Comparative in vitro and in vivo studies have shown that esterification prolongs BUD's anti-inflammatory activity longer than that of corticosteroids that can not form esters. Clinical studies have confirmed the prolonged presence of BUD esters, as well as intact BUD, in human airway tissues: 6 hours postdosing, nasal biopsy concentrations of intact BUD were >10-fold greater than those of fluticasone propionate and at 24 hours BUD was detectable in threefold more biopsies than fluticasone propionate. The impact of esterification on airway selectivity of BUD has also been demonstrated in vivo and using pharmacokinetic/pharmacodynamic models.

CONCLUSIONS

BUD is retained in airways as esters, a novel kinetic mechanism for synthetic glucocorticoids. In preclinical studies this esterification is correlated to a prolonged local tissue binding and efficacy, which is not found when the esterification is inhibited by an esterification blocker. Because less esters are formed in the systemic compartment than in airways/lung, the local benefit:systemic risk ratio may also be improved by this mechanism. BUD possesses favorable clinical properties, including its approved once-daily efficacy in asthma, which is probably in part attributable to esterification. However, a direct proof of the latter in patients requires effective and safe inhibitors of the esterification, which are not yet available. Therefore, evidence to support the therapeutic impact of esterification is still circumstantial.

Inhaled mometasone furoate: a review of its use in adults and adolescents with persistent asthma

Mometasone furoate is a corticosteroid with relatively high in vitro potency. Recent randomised, double-blind, multicentre trials have assessed the efficacy of mometasone furoate delivered by dry powder inhaler over 12 weeks in adults and adolescents with mild to severe persistent asthma. Mometasone furoate 200 microg twice daily or 400 microg once daily in the morning or 200 microg once daily in the evening improved lung function, asthma symptom scores and use of rescue medication to a significantly greater extent than placebo in patients who had previously received only short-acting inhaled beta2-adrenoceptor agonists alone as treatment in 3 trials (n = 195 to 306). In studies in 227 to 733 patients with mild to moderate asthma who were receiving ongoing treatment with inhaled corticosteroids prior to enrolment, mometasone furoate 100 to 400 microg twice daily was consistently better at improving the above indicators of asthma than placebo. Mometasone furoate 100 to 200 microg twice daily was as effective as beclomethasone dipropionate 200 microg twice daily or budesonide 400 microg twice daily and mometasone furoate 200 microg twice daily was as effective as fluticasone propionate 250 microg twice daily. Mometasone furoate 400 or 800 microg twice daily was also consistently more effective than placebo in reducing oral corticosteroid dosages and improving lung function and asthma symptoms in 132 patients with oral corticosteroid-dependent asthma. Once daily administration of mometasone furoate 400 microg appears to be as effective at improving indicators of asthma as twice daily administration of 200 microg. Patients receiving mometasone furoate < or =800 microg/day and recipients of placebo experienced a similar overall incidence of adverse events considered to be related to treatment. The most common of these events were oral candidiasis, headache, pharyngitis and dysphonia. Mometasone furoate 100 to 400 microg twice daily, beclomethasone dipropionate 200 microg twice daily, budesonide 400 microg twice daily or fluticasone propionate 250 microg twice daily were similarly tolerated.

CONCLUSION

Inhaled mometasone furoate is well tolerated, with minimal systemic activity and is equally effective when administered as a divided dose or as a single daily dose. Use of the drug can result in a decrease in requirements for oral corticosteroids in patients with oral corticosteroid-dependent asthma and is as effective as other inhaled corticosteroids currently used in the treatment of mild to moderate persistent asthma. Thus mometasone furoate is suitable for the control of mild to severe persistent asthma in adults or adolescents.