TREATMENT OF STEROID-RESISTANT ASTHMA

Oral corticosteroid-dependent asthma: a 30-year review

OBJECTIVE

To identify novel aspects of the pathogenesis, therapeutic options, and prophylaxis measures of corticosteroid-dependent asthma.

DATA SOURCES

PubMed searches were undertaken of studies published between 1966 and 2006 on the pathogenesis of and corticosteroid-sparing therapies for corticosteroid-dependent asthma. Identified review articles were surveyed for additional and earlier citations. Recent American Academy of Asthma, Allergy, and Immunology meeting abstracts were also searched to identify other recently published and unpublished studies.

STUDY SELECTION

Inclusion of studies in the review was decided by simple agreement of both reviewers, who independently read the "Methods" and "Discussion" sections of articles identified using the search strategy. Quality assessment was performed by the 2 reviewers.

RESULTS

High-dose inhaled corticosteroids are the first-line option for corticosteroid-dependent asthmatic patients with clear efficacy. Omalizumab is effective in reducing oral corticosteroid requirements in allergic asthma. Methotrexate, gold, and cyclosporine have corticosteroid-sparing effects clinically that must be weighed against a serious adverse effect profile. Nebulized diuretics and lidocaine, with a low adverse effect profile, offer promising results but require further study. Clarithromycin and telithromycin seem to have an independent mechanism of inflammatory modulation, but their effect on corticosteroid-dependent asthma remains to be seen. Etanercept offers only early clinical evidence of a role in corticosteroid-dependent asthma.

CONCLUSIONS

With no clear consensus on corticosteroid-sparing treatment in corticosteroid-dependent asthmatic patients, systemic glucocorticoids remain the foremost therapy, with adverse effects that require monitoring and prophylaxis.

Dapsone as an oral corticosteroid sparing agent for asthma

BACKGROUND

Oral corticosteroids are used as a treatment for asthma, however they are often associated with serious side effects. Dapsone is a sulfone with anti-inflammatory properties, therefore it may have a beneficial effect in the treatment of asthma and act as a corticosteroid-sparing agent.

OBJECTIVES

The objective of this review is to assess the safety and efficacy of adding dapsone to oral corticosteroids in adults with stable asthma who are dependent on oral corticosteroids with the intention of eventually minimizing or eliminating the use of these steroids.

SEARCH STRATEGY

The Cochrane Airways group trials register and reference lists of potential articles were searched.

SELECTION CRITERIA

Randomised controlled trials investigating the addition of dapsone compared to placebo in stable corticosteroid dependent asthmatics.

DATA COLLECTION AND ANALYSIS

No trials were found that met the selection criteria.

MAIN RESULTS

No meta-analyses could be performed.

REVIEWER'S CONCLUSIONS

No randomised controlled trials have been published, so there is no reliable evidence to show whether dapsone is beneficial or otherwise in the management of steroid-dependent asthmatic patients. There is a need for well designed randomised controlled trials to be performed. These must be carried out double-blind, since oral corticosteroid reduction requires a judgement on the part of the physician, who may be open to bias if the treatment allocation is known.

Methotrexate as a steroid sparing agent for asthma in adults

BACKGROUND

Sustained oral corticosteroid use can lead to complications, so there is interest in identifying agents that can reduce oral steroid use in people with asthma. Methotrexate has attracted attention as a possible steroid sparing agent in patients with chronic oral steroid dependent asthma.

OBJECTIVES

The objective of this review was to assess the effects of adding methotrexate to oral corticosteroids in adults with stable asthma who are dependent on oral corticosteroids.

SEARCH STRATEGY

The Cochrane Airways Group trials register and reference lists of identified articles were searched.

SELECTION CRITERIA

Randomised trials of the addition of methotrexate compared with placebo in adult steroid dependent asthmatics. Duration of therapy needed to be at least 12 weeks.

DATA COLLECTION AND ANALYSIS

Trial quality was assessed and data extraction was carried out by two reviewers independently. Study authors were contacted for missing information.

MAIN RESULTS

Ten trials involving a total of 185 people were included. Study design and quality, corticosteroid dosages and outcomes varied widely. There was a reduction in oral corticosteroid dose favouring methotrexate in parallel trials (weighted mean difference -4.1 mg per day, 95% confidence interval -6.8 to -1.3) and also in cross-over trials (weighted mean difference -2.9 mg per day, 95% confidence interval -5.9 to -0.2). There was no difference between methotrexate and placebo for forced expiratory volume in one minute (weighted mean difference 0.12 litre, 95% confidence interval -0.21 to 0.45). Hepatotoxicity was a common adverse effect with methotrexate compared to placebo (odds ratio 6.9, 95% confidence interval 3.1 to 15.5).

REVIEWER'S CONCLUSIONS

Methotrexate may have a small steroid sparing effect in adults with asthma who are dependent on oral corticosteroids. However, the overall reduction in daily steroid use is probably not large enough to reduce steroid-induced adverse effects. This small potential to reduce the impact of steroid side-effects is probably insufficient to offset the adverse effects of methotrexate.