Corticosteroids (glucocorticoids), inhaled

Key examples

• Beclometasone
• Budesonide
• Fluticasone

 

Common indications

• Asthma: to treat airways inflammation and control symptoms at ‘step 2’ of therapy where asthma is not adequately controlled by a short-acting β2-agonist alone.
• Chronic obstructive pulmonary disease (COPD): to control symptoms and prevent exacerbations in patients who have severe airflow obstruction on spirometry and/or recurrent exacerbations. Inhaled corticosteroids are usually prescribed in combination with a long-acting β2-agonist and/or a long-acting antimuscarinic bronchodilator.

 

Mechanisms of action

• Corticosteroids pass through the plasma membrane and interact with receptors in the cytoplasm. The activated receptor then passes into the nucleus to modify the transcription of a large number of genes. Pro-inflammatory interleukins, cytokines and chemokines are downregulated, while anti-inflammatory proteins are upregulated. In the airways, this reduces mucosal inflammation, widens the airways, and reduces mucus secretion. This improves symptoms and reduces exacerbations in asthma and COPD.

 

Important adverse effects

• The main adverse effects of inhaled corticosteroids occur locally in the airway, where their immunosuppressive effect can cause oral candidiasis (thrush infection). They can also cause a hoarse voice. In COPD, there is some evidence they may increase the risk of pneumonia. Very little is absorbed into the blood, so there are few systemic adverse effects unless taken at very high dose when systemic side effects including adrenal suppression, growth retardation (children) and osteoporosis may occur.

 

Warnings

• High-dose inhaled corticosteroids, particularly fluticasone, should be used with caution in COPD patients with a history of pneumonia and in children, where there is potential for growth suppression.

 

Important interactions

• There are no clinically significant adverse drug interactions with inhaled corticosteroids.