Chronic Obstructive Pulmonary Disease (COPD) (cont.)

There are a variety of medications prescribed to treat COPD.

Treating airway obstruction in COPD with bronchodilators is similar but not identical to treating bronchospasm in asthma. Bronchodilators are medications that relax the muscles surrounding the small airways thereby opening the airways. Bronchodilators can be inhaled, taken orally or administered intravenously. Inhaled bronchodilators are popular because they go directly to the airways where they work. As compared with bronchodilators given orally, less medication reaches the rest of the body, and, therefore, there are fewer side effects.

Metered dose inhalers (MDIs) are used to deliver bronchodilators. An MDI is a pressurized canister containing a medication that is released when the canister is compressed. A standard amount of medication is released with each compression of the MDI. To maximize the delivery of the medications to the airways, the patient has to learn to coordinate inhalation with each compression. Incorrect use of the MDI can lead to deposition of much of the medication on the tongue and the back of the throat instead of on the airways.

Chlorofluorocarbons (CFCs) have been removed from all MDI inhalers because of the environmental effects on the ozone layer. These have been replaced by a new propellant, hydrofluoroalkane (HFA). Patients may notice that the jet they feel in the back of their throat is less intense when compared with the CFC inhaler. They should be instructed that they are still receiving the same amount of medication though it may feel different than their older inhaler. Another very important point that patients must be aware of is that "floating" these new inhalers does not help in determining the amount of medication left in the MDI. In the past, the CFC devices could be floated in a bowl of water. With more medicine in the inhaler, the canister would sink and gradually float as it emptied. This is not the case with the HFA inhalers. The number of inhalations must be counted to determine if medication is still left in the inhaler. Shaking the inhaler is not an effective method of determining how much medication is left. Often propellant (HFA) will continue to come out of the inhaler even after the medication is used up. At the present only one albuterol inhaler comes with a counter device and this is Ventolin-HFA.

Source: MedicineNet.com
http://www.medicinenet.com/chronic_obstructive_pulmonary_disease_copd/article.htm