Step 4: Maintain Best Lung Function
Optimise Medication Program

Aims:

• relieve symptoms with intensive initial therapy

• use minimum effective doses for maintenance to minimise side-
  effects and maximise compliance

Maintenance corticosteroid therapy:
The use of corticosteroid therapy to maintain asthma control is described in Step 2.

Choose a method of delivery suitable for the age of the patient.
Holding chambers versus nebulisers for beta-agonist treatment of acute asthma
Metered dose inhalers, with holding chambers, are at least equivalent to nebuliser delivery of beta-agonists in acute asthma. Uncertainty over delivery of equipotent doses from the different devices can be overcome by administering beta-agonists at short intervals, titrating the number of treatments according to the patient's response. Side-effects in children may be more pronounced with nebulisers (Cates C, et al, CDSR) [LEVEL 1].

Consider the addition of ipratropium bromide in the maintenance medication for children.
Anti-cholinergic drugs for wheeze in children under the age of two years 
Level 2 evidence from one crossover trial showed that in the home setting, maintenance treatment using an anti-cholinergic drug was perceived by parents to be preferable to nebulised water for the relief of symptoms. Further work is required to clarify the exact role of anti-cholinergic agents in the treatment of wheeze in young children (Everard ML & Kurian M, CDSR) [LEVEL 1].

A long acting beta-agonist may be considered in the maintenance therapy of adults in addition to inhaled corticosteroids in moderate to severe asthma. 
Salmeterol versus theophylline in the maintenance treatment of asthma
Salmeterol may be more effective than theophylline in reducing asthma symptoms, including night waking, and the need for rescue medication. More adverse events occurred in subjects using theophylline when compared to salmeterol (Wilson A, et al, CDSR) [LEVEL 1].

Inhaled corticosteroids plus eformoterol versus placebo
Level 2 evidence from two randomised controlled trials indicates that the addition of eformoterol to inhaled steroids, in adult patients with mild to moderate asthma, produced a reduction in symptoms and improvement in peak flows. One study showed a reduction in exacerbations (Bremner P & Musk B, CAR) [LEVEL 2].

Guidelines for specialist consultation for adults: the patient is not responding to therapy, and/or unacceptable side effects from medication.
Methotrexate as a steroid-sparing agent in adult asthma
Methotrexate has been used as a steroid-sparing agent in chronic asthma. Level 1 evidence from 13 trials showed a modest (25%) fall in dose of oral corticosteroids when given with methotrexate. However, there are very significant risks associated with its use and continuous monitoring for side-effects is required (Davies H, et al, CDSR) [LEVEL 1].

Inhaled corticosteroids should be used in those children who are unresponsive to non-steroid anti-inflammatory therapy.
Comparison of inhaled corticosteroids and non-steroid anti-inflammatory therapy in children
Several Cochrane Systematic Reviews are currently in progress covering the broad categories of inhaled and oral corticosteroids, back titration, steroid-sparing agents, regular versus as-required beta₂-agonists, and anti-leukotriene agents. For further information on the specific topics please