Introduction
A Metered Dose Inhaler is the most common type of inhaler used for treating many respiratory diseases, including Asthma, COPD (Chronic Obstructive Pulmonary Disease), Emphysema and Chronic Bronchitis. Metered Dose Inhaler is also known as MDI or a pMDI where p stands for pressurized. MDI device delivers a measured amount of medication into the lungs in the form of a short burst of aerosolized medicine. These inhalers have a chemical called Hydrofluroalkanes (HFA) to deliver the medicine into the lungs. Using a metered dose inhaler is simple if it is used in the right way. It is usually self-administered by the patient via inhalation. There are several types of metered dose inhaler that deliver a variety of medications.
Inhaled Corticosteroids
MDI with corticosteroids control respiratory disease by suppressing overactive immune response in the lungs which can cause inflammation. Lung Inflammation constricts airways and irritates the lungs, leading to spasms in the smooth muscles lining the lungs. MDIs are available in various brand names such as Flovent, Azmacort, Beclovent, Vanceril, Budesonide, Qvar and Aerobid.
Bronchodilators
Metered dose bronchodilators relax the smooth muscles of the lung airways preventing spasms that restrict or cut off the air supply. There are two types of bronchodilators available: long acting and short acting. Serevent (salmeterol) and Foradil (formoterol) are long-acting bronchodilators taken twice a day and are used to prevent acute bronchospasm. Short-acting bronchodilators are used to treat acute bronchospasm and are often called "rescue inhalers." They are available in different brand names as Ventolin, Proventil, Maxair, Xopenex, Alupent and ProAir.
Combination Inhalers
Corticosteroids and long-acting bronchodilators are also available in combinations for ease of use and efficiency. There is evidence that use of long-acting bronchodilators without an inhaled corticosteroid increases the risk of death during an asthma attack, which makes combination metered dose inhaler medications more popular.
Brand names available for metered dose inhalers combining both a steroid and bronchodilator are Advair and Symbicort.