Tolerance to reduction of oral steroid dosage in severely asthmatic patients receiving nedocromil sodium

Stepping down the dose of inhaled corticosteroids for adults with asthma

BACKGROUND

Asthma is a condition of the airways affecting more than 300 million adults and children worldwide. National and international guidelines recommend titrating up the dose of inhaled corticosteroids (ICS) to gain symptom control at the lowest possible dose because long-term use of higher doses of ICS carries a risk of systemic adverse events. For patients whose asthma symptoms are controlled on moderate or higher doses of ICS, it may be possible to reduce the dose of ICS without compromising symptom control.

OBJECTIVES

To evaluate the evidence for stepping down ICS treatment in adults with well-controlled asthma who are already receiving a moderate or high dose of ICS.

SEARCH METHODS

We identified trials from the Specialised Register of the Cochrane Airways Group and conducted a search of ClinicalTrials.gov (www.ClinicalTrials.gov) and the World Health Organization (WHO) trials portal (www.who.int/ictrp/en/). We searched all databases from their inception with no restriction on language. We also searched the reference lists of included studies and relevant reviews. We performed the most recent search in July 2016.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of at least 12 weeks' duration and excluded cross-over trials. We looked for studies of adults (aged ≥ 18 years) whose asthma had been well controlled for a minimum of three months on at least a moderate dose of ICS. We excluded studies that enrolled participants with any other respiratory comorbidity.We included trials comparing a reduction in the dose of ICS versus no change in the dose of ICS in people with well-controlled asthma who a) were not taking a concomitant long-acting beta agonist (LABA; comparison 1), and b) were taking a concomitant LABA (comparison 2).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results for included studies, extracted data on prespecified outcomes of interest and assessed the risk of bias of included studies; we resolved disagreements by discussion with a third review author. We analysed dichotomous data as odds ratios (ORs) using study participants as the unit of analysis and analysed continuous data as mean differences (MDs). We used a random-effects model. We rated all outcomes using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) system and presented results in 'Summary of findings' tables.

MAIN RESULTS

We included six studies, which randomised a total of 1654 participants (ICS dose reduction, no concomitant LABA (comparison 1): n = 892 participants, three RCTs; ICS dose reduction, concomitant LABA (comparison 2): n = 762 participants, three RCTs). All included studies were RCTs with a parallel design that compared a fixed dose of ICS versus a 50% to 60% reduction in the dose of ICS in adult participants with well-controlled asthma. The duration of the treatment period ranged from 12 to 52 weeks (mean duration 21 weeks; median duration 14 weeks). Two studies were performed in the setting of primary care, two were performed in the secondary care setting and two reported no information on setting.Meta-analysis was hampered by the small number of studies contributing to each comparison, combined with heterogeneity among outcomes reported in the included studies. We found the quality of synthesised evidence to be low or very low for most outcomes considered because of a risk of bias (principally, selective reporting), imprecision and indirectness. Although we found no statistically significant or clinically relevant differences between groups with respect to any of the primary or secondary outcomes considered in this review, the data were insufficient to rule out benefit or harm.

AUTHORS' CONCLUSIONS

The strength of the evidence is not sufficient to determine whether stepping down the dose of ICS is of net benefit (in terms of fewer adverse effects) or harm (in terms of reduced effectiveness of treatment) for adult patients with well-controlled asthma. A small number of relevant studies and varied outcome measures limited the number of meta-analyses that we could perform. Additional well-designed RCTs of longer duration are needed to inform clinical practice regarding use of a 'stepping down ICS' strategy for patients with well-controlled asthma.

Corticosteroid-sparing effect of chromoglycate sodium and nedocromil

The most appropiate management for bronchial asthma is the control of airway inflammation. Corticosteroids are the most effective anti-inflammatory drugs available, but they have a number of side effects; most of these are dose-dependent. In children, asthma control should be accomplished with low steroid doses possibly given by inhalation. In a double-bind placebo-controlled crossover study a group of children with mild to moderate asthma received NED 16 mg/day or BDP 400 μg/day. Values for FEV₁, PEF, symptoms use ofbronchodilators overlapped, whereas bronchial hyper-responsiveness assessed by histamine bronchoprovocation challenge was better with BDP than NED. In another case, one boy with high bronchial hyper-reactivity assessed by provocation test with hypertonic solution, experienced a significant improvement only after 2 weeks of therapy with Deflazacort (2 mg/Kg/day) followed by 4 months on combined treatment with NED (16 mg/day) and BDP (300 μ/day). Authors conclude that NED could have a steroidsparing effect over long-term use.

Alternative agents for anti-inflammatory treatment of asthma

Recent guidelines for the management of asthma have emphasized the role of inflammation in persistent asthma. Medications with anti-inflammatory properties are recommended as the primary long-term-control medications. Of the available choices of long-term-control medications, inhaled corticosteroids are the preferred medication. A literature review of the available studies supports this recommendation of inhaled corticosteroids as the preferred agents for long-term control. Other long-term-control medications--specifically nedocromil, theophylline, and leukotriene modifiers, but not cromolyn--can supplement the beneficial effect of inhaled corticosteroids on pulmonary function and symptom control. Long-acting beta2-adrenergic agonists can also provide an additive clinical benefit to inhaled corticosteroids on symptom control and pulmonary function, but they do not provide additional anti-inflammatory effect. Extended long-term studies of each of the long-term-control medications with anti-inflammatory actions are needed to assess their specific effect on airway remodeling and on the natural history of asthma.

Oral glucocorticosteroid-sparing effect of budesonide administered by Turbuhaler: a double-blind, placebo-controlled study in adults with moderate-to-severe chronic asthma. Pulmicort Turbuhaler Study Group

OBJECTIVE

To determine the ability of budesonide via an inhaler (Pulmicort Turbuhaler; Astra Draco AB) to replace oral glucocorticosteroids (GCSs) in adult subjects with moderate-to-severe asthma.

DESIGN

Double-blind, randomized, and placebo-controlled study, with parallel groups.

SETTING

Multicenter study in outpatient setting.

PARTICIPANTS

Eighty men and 79 women, aged 20 to 69 years, with moderate-to-severe asthma and a mean FEV1 of 58.3% predicted normal. All subjects were receiving oral GCS treatment and 79% of subjects were also receiving inhaled beclomethasone dipropionate (BDP). The mean daily doses of prednisone at baseline, including converted dose of BDP, for the placebo, budesonide 400 microg, and budesonide 800 microg, respectively, were 19.7 mg, 19.5 mg, and 18.7 mg.

MEASUREMENTS AND INTERVENTIONS

After a 2-week baseline period, subjects entered a 20-week treatment period, during which the oral dose of prednisone was reduced by forced down-titration at 2-weekly intervals.

RESULTS

Subjects receiving 400 microg or 800 microg bid of budesonide achieved a significantly greater reduction (82.9% and 79.0% respectively) in oral GCS dose compared with placebo-treated subjects (27%; p<0.001). Two thirds of the subjects receiving budesonide were able to achieve sustained oral corticosteroid cessation, compared with 8% in the placebo group. Additionally, both doses of budesonide resulted in significant improvement in results of pulmonary function tests and asthma symptoms scores, and a significant decrease in the use of bronchodilator therapy. The mean plasma cortisol levels before and after adrenocorticotropic hormone stimulation increased most toward the normal range in the budesonide-treated groups compared with placebo-treated subjects.

CONCLUSION

Budesonide administered via Turbuhaler has a significant oral GCS-sparing capacity with maintained or improved asthma control in adult subjects with moderate-to-severe asthma.

Clinical management of asthma in the 1990s. Current therapy and new directions

Asthma is a serious global health problem affecting nearly 100 million people worldwide. Its rising prevalence and associated morbidity and mortality are of increasing concern. Traditionally, symptomatic control of bronchoconstriction with beta 2 agonists and theophylline has been the mainstay of therapy. However, during recent years, inflammation has been recognised as the predominant cause of reversible airway obstruction and airway hyperreactivity. As a result, the emphasis in treatment has shifted to the early use of inhaled corticosteroids to control airway inflammation. beta 2 agonists are best used on an as-needed basis for the relief of acute bronchoconstriction and for the prevention of exercise-induced asthma. Sustained release theophylline or an inhaled long-acting beta 2 agonist may effectively control nocturnal symptoms. Preliminary studies involving agents active in the 5-lipoxygenase pathway as preventive therapy are encouraging. Further studies are needed to define their role in the management of asthma.

Nedocromil sodium

OBJECTIVE

To summarize the available pharmacokinetic and pharmacologic data on nedocromil sodium and to present representative clinical trials of this new agent in both mild-to-moderate and severe chronic asthma and allergic rhinitis. Adverse effects are reviewed.

DATA SOURCES

A MEDLINE search was used to identify pertinent literature, excluding reviews and foreign-language articles. All available English-language studies were reviewed.

DATA EXTRACTION

Pivotal and representative studies are discussed relating to the following issues: pharmacology and pharmacokinetics, management of patients with non-steroid-dependent and steroid-dependent asthma, comparison with sodium cromoglycate (cromolyn), comparison with inhaled beclomethasone dipropionate, management of exercise-induced asthma, use in children with asthma, and use in allergic rhinitis.

DATA SYNTHESIS

Nedocromil sodium is chemically grossly unrelated to cromolyn but has similar pharmacology, pharmacokinetics, and therapeutic benefits. Although ineffective in relieving acute asthma attacks, nedocromil appears to be superior to placebo in lessening the severity of chronic asthma and protecting against allergen-induced asthma when taken as chronic prophylaxis. Single doses attenuate exercise-induced asthma. It is also effective in the management of allergic rhinitis. Results have varied when nedocromil has been compared with cromolyn or inhaled beclomethasone. Studies to date indicate that, overall, nedocromil is not significantly better than cromolyn and is no better than or is inferior to inhaled beclomethasone, although individual response appears to be variable, with no identifiable predictive factors.

CONCLUSIONS

Individual patients may receive marked improvement from nedocromil therapy, but there are no factors that identify which patients will respond. Nedocromil may be particularly useful in adults who frequently fail to respond to cromolyn.

Steroid sparing effect of nedocromil sodium in asthmatic patients on high doses of inhaled steroids

Nedocromil sodium is a non-steroidal prophylactic agent developed for the management of asthma. We have assessed the steroid sparing potential of inhaled nedocromil sodium 4 mg four times daily in a randomized, double blind, placebo controlled study in 69 asthmatic subjects controlled on inhaled beclomethasone dipropionate in the dose range 1000-2000 micrograms daily. Following a 4 week run-in period subjects added nedocromil sodium or placebo by metered dose inhaler to their usual medication for a further 4 weeks. The dose of inhaled steroid was then reduced at fortnightly intervals according to a predetermined schedule, with monitoring of asthma severity, symptom scores, bronchodilator use and peak flow recordings. Sixty subjects entered the steroid reduction phase and achieved median (range) % decreases in steroid dose of 80 (17-100)% with nedocromil sodium compared to 65 (0-100)% with placebo (P = 0.34) with 14 patients in the nedocromil sodium group and 10 in the placebo group being withdrawn completely from inhaled steroids. Subjective global assessment scores were significantly better with nedocromil sodium (mean 2.14) than with placebo (2.93; P < 0.02) though there was no difference between individual daily symptom scores. In this study therefore in asthmatic patients controlled on high doses of inhaled steroids, nedocromil sodium was well tolerated but the small differences in steroid sparing effect between nedocromil and placebo were not statistically significant.

Nedocromil sodium. An updated review of its pharmacological properties and therapeutic efficacy in asthma

Nedocromil sodium, the disodium salt of a pyranoquinoline dicarboxylic acid, has anti-inflammatory properties in vitro, in animal models of asthma, and in humans, as evidenced by inhibition of inflammatory cell activation and mediator release, early and late allergen-induced bronchoconstriction and airway hyperresponsiveness. Recent therapeutic trials confirm the safety and efficacy of inhaled nedocromil sodium as adjunctive therapy in adult patients whose asthma is not adequately controlled by beta-agonists alone. Nedocromil sodium has also been shown to improve symptoms when added to existing treatment with methylxanthines and corticosteroids. Some studies show nedocromil sodium to be successful replacement therapy for methylxanthines, in addition to enabling a modest reduction in inhaled corticosteroids in some patients. Thus, nedocromil sodium may be suitable in patients with asthma as an adjunct to existing therapy, as an alternative to regularly administered oral and inhaled beta-agonists and oral methyl-xanthines, and potentially, to low dose inhaled corticosteroids as maintenance therapy in patients with mild to moderate asthma being considered for corticosteroid therapy.

Issues and advances in the pharmacotherapy of asthma

Evidence is accumulating that inflammation of the airways is directly responsible for the increased bronchial hyperresponsiveness (BHR) and lung function obstruction in asthma. Bronchoprovocation with non-specific, direct bronchoconstrictors (methacholine and/or histamine) can be used as an indirect measurement of inflammation. Thus bronchoprovocation is a useful method for evaluating the long-term benefits of various therapies in asthma. The focus of asthma therapy research is now on the development of anti-inflammatory agents. Inhaled corticosteroids are currently the most potent anti-inflammatory agents in the treatment of asthma and so are generally the most effective in reducing BHR with long-term use. Non-corticosteroid anti-inflammatory agents that are currently available are reviewed. Recent studies have suggested that regular use of inhaled bronchodilators may actually be detrimental in asthma. At this time the data is still inconclusive but certainly warrants the attention of practitioners and requires further research, particularly in relation to the long-acting beta 2-agonists, formoterol and salmeterol.

Double-blind crossover study of nedocromil sodium in partially reversible chronic obstructive airways disease

The efficacy of 8 weeks of treatment with 4 mg of nedocromil sodium 4 times daily in the management of partially reversible chronic airflow obstruction was evaluated in a randomized, double-blind, placebo-controlled crossover trial at Repatriation General Hospital, Western Australia. Sixty-seven patients with a mean forced expiratory volume in 1 s (FEV1) of 0.99 L, which improved by 21.8 percent after beta 2-adrenergic bronchodilator, took part in the full 24-week study. After a 4-week run-in period, in addition to their regular therapy comprised of inhaled or oral bronchodilators and steroids (which remained unchanged), patients were randomly allocated to receive treatment with nedocromil sodium or placebo for 8 weeks. This was followed by a 4-week washout, and then the patients were given the alternative test treatment to that given in the first period for another 8 weeks. Compared with placebo, patients receiving nedocromil sodium had improvement in their morning and evening peak flow rates, symptom scores for cough, sleep disturbance, and overall treatment efficacy. Hence, treatment with nedocromil sodium should be considered for patients with partially reversible chronic airflow obstruction not fully controlled with bronchodilators and steroids.

Comparison of nedocromil sodium at two dosage frequencies with placebo in the management of chronic asthma

Nedocromil sodium (4 mg b.d. or q.i.d.) was added to the therapy of 76 chronic asthmatic patients in a four-centre, double-blind cross-over, placebo-controlled trial. Patients had troublesome symptoms uncontrolled by high doses of inhaled corticosteroids (mean 1450 micrograms). In 54 patients who completed the study, nedocromil sodium was significantly more efficacious than placebo (P < 0.01) in relieving morning chest-tightness and cough, in reducing total diary card score and nocturnal bronchodilator usage, and in increasing morning and evening peak flow. Asthma severity at clinic visits decreased significantly (P = 0.001) following treatment with nedocromil sodium, which was globally rated more effective than placebo (P < 0.01). Treatment differences favored q.i.d. over b.d. dosage but without statistical significance. There were no serious adverse effects. Although the pulmonary function changes were small, these findings suggest that the addition of nedocromil sodium may benefit asthmatic patients who are inadequately controlled by high doses of inhaled corticosteroids.