ASTHMA INHALER OVERVIEW

Inhaled medications are the cornerstone of asthma therapy, but they can only be effective if they are used properly. Using your inhaler correctly delivers the medication to your lungs, where it can work to control your symptoms. Using an inhaler incorrectly means that little or no medicine reaches the lungs.

Studies have shown that almost everyone can learn proper inhaler technique with adequate training and practice. This article discusses how to use a metered dose inhaler for adults. A separate article discusses inhaler use in children. (See "Patient information: Asthma inhaler techniques in children (Beyond the Basics)".)

Other topics about asthma are available separately. (See "Patient information: Asthma treatment in adolescents and adults (Beyond the Basics)" and "Patient information: Asthma symptoms and diagnosis in children (Beyond the Basics)" and "Patient information: How to use a peak flow meter (Beyond the Basics)" and "Patient information: Trigger avoidance in asthma (Beyond the Basics)".)

TYPES OF ASTHMA INHALERS

Two major types of inhalers are used to deliver asthma medication: metered dose inhalers (MDIs) and dry powder inhalers (DPIs). Each type has advantages and disadvantages. The techniques for using the various MDIs and DPIs are described below.

METERED DOSE ASTHMA INHALERS

Metered dose inhalers (MDIs) are used to deliver a variety of inhaled medications, including quick relief bronchodilators such as albuterol, Proventil, Ventolin, and controller medicines such as glucocorticoids (Flovent HFA, QVAR, and others). You deliver the medication by pushing down on a canister (picture 1).

New inhalers in 2008 and 2009 — The inhaler canister contains the medicine and other products that help to deliver the medication to the lungs. Previously, inhalers contained a chemical known to damage the ozone layer.

As a result, most inhalers in the United States were reformulated after December 2008. The new inhalers use a chemical called hydrofluoroalkane (HFA) to deliver the medication to the lungs. HFA devices may have a different taste compared to the previous inhalers, and the spray may feel softer. However, this does not mean the medicine is not reaching your lungs.

In addition, HFA inhalers need to be cleaned and primed to prevent medication build up and blockage. Each manufacturer will provide instructions about how to use their inhaler. These instructions should be reviewed carefully. (See 'How to use a metered dose inhaler' below.)

HFA inhalers may be more expensive than the older inhaler. Talk to your healthcare provider if you have difficulty paying for your medications because assistance programs may be available.

How to use a metered dose inhaler — Each inhaler manufacturer has specific instructions for using their inhaler; the following are general instructions.

When using a metered dose inhaler FOR THE FIRST TIME (with or without a spacer), prepare the inhaler first:

• Shake the inhaler for five seconds
• Prime the inhaler by pressing down the canister with the index finger to release the medication. Hold the inhaler away from your face to prevent medication from getting into your eyes. Press the canister down again 3 times.

After an inhaler is used for the first time, it does not need to be primed again unless you do not use it for two weeks or more.

Instructions for using the inhaler are available in the Table (table 1).

Getting the most out of your inhaler — Several common mistakes can prevent inhaled medications from getting to the lungs. The following tips can help to get the most out of a metered dose inhaler.

• Remember to take the cap off the mouthpiece
• Be sure there is medication in the canister (see 'Determine when an inhaler is empty' below)
• Inhale through the mouth when breathing in the medication, not the nose
• Take a slow, deep breath at the same time you press down on the medication canister

If you have difficulty timing your breath while spraying the medication, there are inhalers that automatically release the medication when you take a breath (ie, Maxair Autohaler). Another alternative is to use a spacer or a dry powder inhaler (DPI). (See 'Spacer devices' below and 'Dry powder asthma inhalers' below.)

Cleaning the metered dose inhaler — HFA inhalers must be cleaned on a regular basis to prevent medication build up and blockages. Most manufacturers recommend cleaning the mouthpiece at least once per week. To clean:

• Remove the medication canister and cap from the mouthpiece. Do not wash the canister or immerse it in water.
• Run warm tap water through the top and bottom of the plastic mouthpiece for 30 to 60 seconds.
• Shake off excess water and allow the mouthpiece to dry completely (overnight is recommended).
• If you need the inhaler before the mouthpiece is dry, shake off excess water, replace canister, and test spray two times (away from the face).

Spacer devices — A spacer device holds the medicine in a chamber after you squeeze the canister, allowing you to inhale slowly and deeply once or twice (picture 2). Spacers can dramatically decrease the amount of medicine deposited in the back of the mouth or on the tongue, allowing much more of the medicine to reach the lungs. HFA inhalers do not usually require a spacer, although a spacer may be recommended if you have difficulty timing the spray with inhalation.

There are many spacers on the market, although little is known about the benefit of one type versus another. In general, larger-sized spacers appear to be more effective than smaller ones. Proper technique and frequent cleaning are important to ensure optimal drug delivery. Be sure to read the package insert that comes with the spacer for specific directions about cleaning and use.

Cleaning the spacer — Although the powder residue that is deposited in the chamber is not harmful, the spacer should be cleaned periodically, approximately every one to two weeks. Wash the spacer with warm water and dishwashing detergent; washing with water alone causes an electrostatic charge to develop, reducing the effectiveness of the spacer. After washing, air-dry the spacer before the next use.

Determine when an inhaler is empty — It is not always possible to determine when your inhaler is empty by shaking it; even when the medication is gone, some propellant remains in the canister. A few inhalers now have dose counters to track the amount of medication used, including Ventolin-HFA and Proventil (picture 3). Ask your healthcare provider if a counter is available on your inhaler.

If your inhaler does not have a counter but you use it on a regular basis (eg, two puffs twice per day), you will need a refill in 30 days. Write the date you will need the refill on the canister in permanent marker, and mark this date on your calendar or planner.

If you use your rescue inhaler infrequently, write the date you start using it on the canister in permanent marker and consider refilling it after three to four months, or sooner if you think it is no longer effective.

Another option is to check the package insert to determine the number of puffs or sprays available in the inhaler. You can then divide that number by the average number of puffs you use each month. For example:

• If you use about eight puffs each week, divide 200 by 8 = 25 weeks (about 5 months)
• Write the date you will need a refill on the canister in permanent marker, and mark this date on your calendar or planner.
• Refill your inhaler prescription at least one or two weeks before you will need it.
• Be aware, however, that you may need a refill sooner if you use your inhaler more frequently.

In the past, you may have been told to drop the canister into a bowl of water and see how it floats. However, this method is not reliable and it is no longer recommended. Spraying the inhaler is also not recommended because even an empty inhaler will continue to spray.

DRY POWDER ASTHMA INHALERS

Dry powder inhalers (DPIs) contain a dose of asthma medication in a dry powder form. DPIs deliver a fine powder to the lungs when the patient breathes in (picture 4). With a DPI, you do not need to coordinate squeezing the canister and inhaler. However, you must inhale more forcefully with a DPI than with a traditional inhaler. Thus, DPIs may not be suitable for elderly people or people with nerve or muscle weakness. Also, it is important not to blow (exhale) directly into the device before breathing in, as this can scatter the medicine before it can be inhaled.

Examples of DPIs include the quick relief medication Foradil, the controller medications Asmanex and Pulmicort flexhaler, and the combination inhalers Advair and Symbicort. Spiriva is a DPI that contains a long acting medication to treat people with COPD.

DPIs come in two main types (picture 4):

• Multiple dose devices, which contain up to 200 doses
• Single dose devices (Foradil Aerolizer, Spiriva Handihaler), which require you to place a capsule in the device immediately before each treatment. DPI capsules should NOT be swallowed.

DPIs do not contain CFC or HFA, but some contain tiny amounts of lactose.

How to use a DPI — The instructions for using a DPI depend upon the individual type and brand. The following are general instructions. Consult the package insert with your device for specific instructions.

• Remove the cap. For single use devices, load a capsule into the device as directed.
• Breathe out slowly and completely (not into the mouthpiece).
• Place the mouthpiece between the front teeth and seal the lips around it.
• Breathe in through the mouth quickly and deeply over two to three seconds.
• Remove the inhaler from the mouth. Hold your breath for as long as possible (4 to 10 seconds).
• Breathe out slowly.

Cleaning the DPI — Most DPIs should NOT be washed with soap and water. The mouthpiece can be cleaned with a dry cloth. Consult the instructions with your inhaler for further information.

ASTHMA ATTACK CARE AND PREVENTION

Work with your healthcare provider to ensure that your medication regimen is working to prevent and treat asthma attacks.

Depending upon the severity of your asthma, your treatment plan may include regular visits with your provider, one or more medications, avoiding asthma triggers, and/or home peak flow monitoring. At each visit, you should show your clinician how you use an inhaler to be sure that you are using the correct technique. (See "Patient information: How to use a peak flow meter (Beyond the Basics)" and "Patient information: Trigger avoidance in asthma (Beyond the Basics)".)

Keep an adequate supply of medication — You should always have an adequate supply of your medication(s). This includes being sure that your medication is not expired and that you always have a spare inhaler.

WHERE TO GET MORE INFORMATION

Your healthcare provider is the best source of information for questions and concerns related to your medical problem.

This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.

Patient level information — UpToDate offers two types of patient education materials.

The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.

Patient information: Asthma in adults (The Basics)
Patient information: Inhalers (The Basics)
Patient information: How to use your metered dose inhaler (adults) (The Basics)
Patient information: How to use your dry powder inhaler (adults) (The Basics)
Patient information: Medicines for asthma (The Basics)
Patient information: Cystic fibrosis (The Basics)

Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.

Patient information: Asthma inhaler techniques in children (Beyond the Basics)
Patient information: Asthma treatment in adolescents and adults (Beyond the Basics)
Patient information: Asthma symptoms and diagnosis in children (Beyond the Basics)
Patient information: How to use a peak flow meter (Beyond the Basics)
Patient information: Trigger avoidance in asthma (Beyond the Basics)

Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.

An overview of asthma management
Beta agonists in asthma: Acute administration and prophylactic use
Beta agonists in asthma: Controversy regarding chronic use
Delivery of inhaled medication in adults
Management of stable chronic obstructive pulmonary disease
The use of chromones (cromoglycates) in the treatment of asthma
The use of inhaler devices in adults
Treatment of acute exacerbations of asthma in adults
Treatment of intermittent and mild persistent asthma in adolescents and adults
What do patients need to know about their asthma?

The following organizations also provide reliable health information.

• Center for Disease Control and Prevention

     (www.cdc.gov/ASTHMA/)

• American College of Chest Physicians

     (http://www.chestnet.org/accp/patient-guides/patient-instructions-inhaled-devices-english-and-spanish)

• American Lung Association

     (http://www.lungusa.org/lung-disease/asthma/living-with-asthma/making-treatment-decisions/asthma-medicines.html)

• American Academy of Allergy, Asthma, and Immunology

     (www.aaaai.org/patients.stm)

• American College of Allergy, Asthma, and Immunology

     (www.acaai.org/allergist)

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