Allergy & Asthma-Kent H. DeYarman, MD

Topics in Allergy

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Asthma-General Concepts
and Basics of Management

 

Asthma is an inflammatory disease of the respiratory mucus membranes. This includes inflammation of the mucus membranes that line the bronchial tubes but, in some people, includes inflammation of the membranes in the nose, sinuses, and eyes.

 

Inflammation is a process where specific chemicals are released from cells in the respiratory membranes and these chemicals attract inflammatory cells (eosinophils, etc) causing them to migrate to the respiratory tract, adhere to the respiratory membranes and become metabolically active. The inflammatory cells are normal cells that reside in areas of the body other than the respiratory tract and are usually inactive. When they migrate to the respiratory tract they settle just under the lining layer and remain there for several days or longer. Up to 10 million per square inch have been counted. During their stay they release materials that cause swelling of the membrane, they increase mucus production and cause mucus to become thick and sticky and they release materials that injure and damage the protective respiratory membranes.

 

When the respiratory membranes are injured by the inflammatory cells, small nerve endings in the membrane lose their protective covering and are irritated and exposed to the airway. Many triggering factors can then irritate the nerve endings which in turn causes constriction of the bronchial tubes. The more inflamed the airways become, the more "touchy" they are.

 

Several factors are known to increase and contribute to airway inflammation in asthma:

 

*Inborn or hereditary factors.

*Prolonged smoke exposure or some occupational exposures to chemicals.

*Some virus infections including influenza.

*Allergies

*Chronic sinus infections, stomach acid reflux and other factors may add to the inflammation.

Our goals in treating your asthma include:

 

*Prevention of both chronic & troublesome symptoms.

*Maintain normal activity levels.

*Prevent flareups of asthma and minimize the need for emergency room visits and hospitalization.

*Minimize the impact of factors that contribute to your asthma.

*Provide optimal medication treatments:
- minimal side effects both short term and long term. - convenient medication schedule. - cost considerations (this can be the most difficult aspect)

*Meet your needs and expectations.

You may have additional goals and concerns and you should express those to us.

 

Managing your asthma may require

 

*medications

*controlling factors that contribute to asthma

*learning to monitor asthma to know when and how to intervene when the severity of your asthma changes.

We will discuss these topics one at a time. Although all of these topics are important the use of medications is probably the most confusing area so we will discuss that first. It can be helpful to think of medications for asthma as either Quick Relief (Rescue) medications or Controller Medications.

 

Quick Relief (Rescue) medications - these are typically used only when needed or for short periods of time for symptom relief or restabilization of flareups. When asthma is well controlled you typically will not need these. Increased need for rescue medications is a sign your asthma is not well controlled and you may need to intervene in other ways. Rescue medications include:

 

*Short acting beta 2 agonists (medications related to adrenaline)
- albuterol (currently available as ProAir, Ventolin, Proventil) - usually used as an inhaler but also available to use in a nebulizer and available in oral pill or liquid forms. Don't worry about the HFA confusion. HFA is just the new propellant in the medication and they are all HFA inhalers now. The albuterol in the inhaler is the same as it always has been. Ventolin now has a dose counter on the inhaler. - levalbuterol (Xopenex) - think of this as a purified albuterol. They kept the part that mainly dilates bronchial tubes and got rid of the part that caused most of the side effect of over stimulation. Available as an inhaler and for use in a nebulizer. - metoproterenol (Alupent) - an older bronchodilator similar to albuterol available as an inhaler, for use in a nebulizer, and in pill & liquid oral forms. - pirbuterol (Maxiar) - available in an inhaler. Like Xopenex this causes less stimulation than albuterol for some people.

*Short acting anticholinergic bronchodilators - these dilate bronchial tubes by a mechanism that is quite different than the short acting beta 2 agonists. They are usually less effective than the short acting beta 2 agonists. They may be particularly helpful in COPD but can help some patients with asthma too. They have an additive effect with short acting beta 2 agonists and are often used in combination.
- ipatropium bromide (Atrovent) - available as an inhaler and for use in a nebulizer.

*Combination short acting bronchodilators - these combine a short acting beta 2 agonist with a short acting anticholinergic bronchodilator in the same inhaler or vial to use in a nebulizer.
- Combivent - is albuterol and atrovent combined in one inhaler. It may be written as Combivent or using the generic names. It may be used as needed but is sometimes prescribed on a regular basis. If you are using Combivent you would not also be using other short acting bronchodilators at the same time.

 - Duoneb - the same thing as Combivent but in a unit dose vial form to use in a nebulizer. It may be written as Duoneb or using the generic names (albuterol/ipatropium). It may be used as needed but is sometimes prescribed on a regular basis. If you are using Duoneb you would not also be using other short acting bronchodilators.

*Short courses of oral corticosteroids (also known as cortisones or steroids) or short courses of high dose inhaled cortisones. These are not usually thought of as rescue medications but we do use them to restabilize asthma during flareups so they listing them here makes some sense. Short courses of corticosteroids do not have the same side effect risks as seen with long term use. Examples include Prednisone, Methylprednisone, Medrol, Prelone, Pediapred).

Controller medications are medications meant to be taken daily to treat asthma rather than as needed. You take these even if you are feeling fine and have no symptoms at all. Some controller medications "heal inflammation" (stop the injury process caused by the inflammation cells). Others do not heal but act as long acting bronchodilators, opening bronchial tubes for 12 or 24 hours rather than for 4-6 hours seen with short acting bronchodilators.

 

Controller medications that help heal respiratory inflammation:

 

*Inhaled cortisones (steroids) - here are many of these. All are similarly effective. Some are easier to take than others. They do not have the cortisone side effects risks seen with oral cortisones. Newer inhaled cortisones include (fluticasone)Flovent, budesonide(Pulmicort), mometasone(Asmanex), beclomethasone(Qvar). Older inhaled cortisone include triamcinolone acetonide(Azmacort), flunisolide(Aerobid). These are available as inhalers with many unusual variations on how the inhaler is used. Pulmicort is also available for use in nebulizers.

*Leukotriene inhibitors - these block the effects of leukotrienes which are some of the chemicals released in the inflammation process that cause tissue injury and attract the inflammation cells that cause lung injury. There are 3 of these available. In general they tend to be less effective than inhaled cortisones but some people find they are extremely effective. It usually takes about a month to tell how effective they will be for you. They are often used in addition to inhaled cortisones for an additive effect. They may also help upper respiratory (nose and sinus) symptoms.

zilueton (Zyflo and Zyflo CR which is a long acting version) - the first leukotriene inhibitor. It is taken 2 times daily (Zyflo CR) or 4 times daily (Zyflo). It cannot be taken with food. It has some drug interactions. Liver function blood tests must be done periodically. For these reasons it is not the most popular leukotriene inhibitor.

zafirlukast (Accolate) - the second leukotriene inhibitor available. It cannot be taken with meals and does have some interactions with other medications but no lab tests are required. It is taken 2 times daily.

montelukast (Singulair) - once daily. With or without meals. No drug interactions. No lab tests are required.

*Mast Cell Stabilizers - prevent the release of many chemicals that cause inflammation. Theoretically these should prevent inflammation from even occurring but in practice most people find them less effective than inhaled cortisones or leukotriene inhibitors. They need to be taken several times a day and this is an additional drawback.
- cromolyn sodium (Intal) - available in an inhaler and for use in a nebulizer. - nedocromil sodium (Tilade) - available in an inhaler.

Controller medications that are Long Acting Bronchodilators - these medications have no ability to heal bronchial tube inflammation but instead dilate bronchial tubes for 12-24 hours depending on the medication rather rather than for 4-6 hours seen with short acting bronchodilators. They are meant to be taken regularly. They should not be used on an as needed basis. They are nearly always (with a few exceptions) used in conjunction with one of the controller medications that does have healing effects on respiratory membranes.

 

*Long acting beta 2 agonists (adrenaline derivatives) - these are similar to albuterol and other short acting beta 2 agonists but last 12 hours instead of 4-6 hours.

- salmeterol (Serevent) - comes in an inhaler known as a diskus. Available in other countries in a regular cartridge inhaler. It is part of Advair-see combination medications below. - formoterol (Foradil) - comes in a capsule that is put in an Aerolizer (basically a gadget made for Foradil) and inhaled every 12 hours. Similar to Serevent but faster onset of action. It is part of Symbicort-see combination medications below.

*Long acting anticholinergic medications - similar to Atrovent (see above) but the one available lasts 24 hours rather than 4-6 hours.

*tiotropium bromide (Spiriva) - a capsule that is placed in a Handihaler (yet another gadget). The contents of capsule are inhaled through the Handihaler. Taken once daily. If you take Spiriva you should not be talking short acting anticholinergic medications such as ipatropium, Atrovent, or Duoneb.

*theophylline - an older bronchodilator taken orally and is available in preparations that last varying periods of time but usually prescribed in 12 hour or 24 hour forms. Rarely used now because of many annoying and some dangerous side effects compared to the long acting beta 2 agonist bronchodilators. Examples include Theodur, Slobid, Uniphyll, Unidur, Theo-24, etc)

*Combinations of controller agents that heal tissue and long acting bronchodilators. These combine inhaled cortisones with inhaled long acting bronchodilators in one inhaler. If you need both it is much easier to use one of these rather than two separate inhalers.

 

*Advair - combines Flovent and Serevent. Comes in an inhaler known as a diskus and in a regular cartridge inhaler. Available in several different strengths of inhaled cortisone. The dose of Serevent is the same in both.

*Symbicort - combines Pulmicort and Foradil. Comes in a regular cartridge inhaler. Available in two different strengths of inhaled cortisone. The dose of Foradil is the same in both.

Controlling Contributing Factors. In addition to appropriate use of medications it is important to identify factors that contribute to the inflammation of asthma and factors that can trigger asthma even if they do not contribute to the underlying inflammation. It will be important to address:

 

*allergic factors if they are playing a role in your asthma. Controlling allergic factors may require changes to your home or work environment. Allergy shots or immunotherapy (either traditional immunotherapy or Xolair-anti IgE therapy) may be indicated to reduce the impact of allergic factors.

*it will be important to avoid viral respiratory infections if possible. Vaccination for influenza and sometimes for pneumonia may be indicated.

*avoidance of smoke, pollutants, respiratory irritants, and occupational factors.

*controlling stomach acid reflux even though it may not be obvious may be important.

*treating sinus disease can help control and manage asthma.

*some medications used for other problems can worsen asthma. These may need to be changed if possible.

Monitoring Asthma. The severity of asthma can change and can range from very mild to very severe in the same person. It will be important to recognize these changes, know their meaning, and be able to intervene with specific plans and guidelines to prevent asthma flares from becoming severe. Our goal in helping you monitor your asthma is for you to have the tools available at home to enable you to treat changes in your asthma without needing emergency rooms or additional visits to the doctor. There are several ways to monitor your asthma. We will give you specific guidelines for monitoring and intervention no matter what way you chose to do the monitoring. Monitoring may be done by:

 

*peak flow meter monitoring. This can be as simple or elaborate as you wish. Technology is beginning to intervene here. New peak flow meters have memory chips to remember your prior peak flow readings. iphones now have an Application that allows you to set up personalized peak flow monitoring plans on your iPhone. When you enter your peak flow it automatically graphs it on your peak flow graph and tells you if you should make any changes in treatment. You can even email the graphs and data to your doctor (or anyone else for that matter). See itunes App Store and look for the Asthma-Charter App.
 
www.asthma-charter.com

*changes in signs and symptoms can be used in place of peak flow monitoring for some people with good results. You still need written guidelines to know when and how to intervene when signs and symptoms change.

*change in use of rescue medications can be used in place of peak flow monitoring for some people with good results. You still need written guidelines to know when and how to intervene when signs and symptoms change.

You will benefit more over time by learning as much about asthma in general and your asthma in particular. Attention to the areas discussed above (Medications, Control of Contributing Factors, Monitoring and Intervention) should enable you to control your asthma rather than it controlling you.