People using two different inhalers for common chronic lung diseases are more than 50 per cent more likely to have a heart attack than those on just one, new University of Otago-led research reveals.

Inhaled long-acting muscarinic antagonists (LAMAs) and long-acting beta-agonists (LABAs) are the main drugs used to treat chronic obstructive pulmonary disease (COPD) – the umbrella medical term for emphysema and chronic bronchitis. While both drugs are bronchodilators and open the airways, they work in different ways and in some cases, patients are prescribed both.

Research undertaken by Otago and Auckland universities in New Zealand, found that when these drugs are taken together, the patient’s risk of suffering an acute coronary event increases.

The research team says that people with COPD already have a high risk of acute coronary syndrome, so it is important to identify factors that might increase that risk even further.

The findings of a higher risk of acute coronary syndrome with dual therapy is something for patients and healthcare providers to consider when weighing up the potential benefits and harms of escalating treatment from one to two long-acting bronchodilators – especially for those patients who have a high absolute risk of future cardiovascular events.