There are other treatments that can be added to reliever and preventer inhalers if needed, such as preventer tablets and long-acting relievers (used as preventers and combination inhalers).

Long acting ß₂ agonists (LABA) include salmeterol, formoterol and vilanterol. LABA have a rapid onset of action and their effects can last for over twelve hours. LABA are included in the BTS guidelines from step 3.

LABA should only be prescribed to patients regularly using an ICS, LABA are commonly prescribed as combination inhalers with inhaled corticosteroid and this can improve patient adherence. Where the patient experiences no benefit from the LABA they should be discontinued.

Salmeterol and vilanterol should not be prescribed for the treatment of acute asthma attacks.

Leukotriene receptor antagonists (LTRA) such as montelukast and zafirlukast are included in step 3 of the BTS guidelines.

BTS/SIGN guidance recommends LTRA in adults and children over 5 years of age who have not responded to LABA or who are taking a LABA and ICS but are still symptomatic.

Children aged 2 and over who are unable to use ICS and are still symptomatic despite optimal SABA therapy can be prescribed montelukast in combination with a short acting reliever, whilst zafirlukast is licensed for use in patients 12 years and over.

Leukotrienes are potent inflammatory mediators released from mast cells and eosinophils. In asthmatic patients these mediators have been shown to cause bronchoconstriction, mucus secretion, and increased vascular permeability. LTRA have a high affinity to block the leukotriene receptors, this blockade inhibits bronchoconstriction. Montelukast and zafirlukast achieve bronchodilation within two hours of administration.

Methylxanthines

Theophylline and aminophylline can be trialled in patients with persistent symptoms despite use of maximal tolerated doses of LABA and ICS. Theophylline has a bronchodilator and anti-inflammatory effect which can benefit patients with asthma and COPD.

Theophylline has a narrow therapeutic window and the possibility of side effects can be minimized by slowly titrating the dose upwards. Treatment should be discontinued in patients who show no response to treatment.

Modified release methylxanthines should be prescribed by brand as the rate of drug release and absorption can vary between brands.