Drug Action: How Bronchodilator Drugs Work

Bronchodilator drugs are often used to prevent or relieve wheezing and shortness of breath caused by disorders such as asthma. In these conditions, the bronchi (airways in the lungs) become abnormally narrowed because muscles in their walls contract. Bronchodilators work by widening the airways and thereby increasing the air flow.

Before drug

The airway narrows as the muscle layer in its walls contracts. The flow of air to the lungs becomes reduced.

After drug

The drugs act on the muscle cells of the airway. The muscles relax, and the airway widens, increasing air flow.

From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.

The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.

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