Current BTS asthma guidance notes that long-acting muscarinic antagonists appear to be as effective as salmeterol in the short term and may be superior to doubling the dose of inhaled corticosteroid (ICS) in fixed airways obstruction. Longer term studies are required to confirm this evidence. It adds that there would also appear to be benefit in adding tiotropium to ICS and salmeterol in patients who remain symptomatic despite these medications.