Definition: Controller Medications
Many people with asthma need to take medication every day to control their asthma and prevent symptoms from developing. These are called controller medications (also called preventive or maintenance medications). Most work by reducing inflammation of the airways; others work by relaxing the airways and making them wider. Controller medications are slow acting, meaning that they can take days or even weeks to begin working. They don't provide immediate relief of symptoms and shouldn't be used when an effect is needed quickly. This requires faster-acting medications (known as rescue medications) that can work on the spot.
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