Overview of Step 4 therapy
Step 4 therapy is indicated for patients who remain uncontrolled despite optimised Step 3 therapy. It is rarely indicated as initial therapy.
Consider referral to a respiratory physician if the diagnosis is in doubt.
Step 4 therapy consists of:
- regular daily medium-dose inhaled corticosteroid plus long-acting beta2 agonist (ICS+LABA) therapy, plus an as-required reliever—most likely to be beneficial in patients with type 2 airway inflammation (identified by elevated blood eosinophil concentration [more than 300 microlitres] or elevated fractional exhaled nitric oxide [FeNO] [more than 25 parts per billion])
- triple therapy using a low-dose ICS+LABA (Step 3) with a long-acting muscarinic antagonist (LAMA), plus an as-required reliever—most likely to be beneficial in patients without type 2 airway inflammation.
Other options for Step 4 therapy are used less frequently.