Using InhalersFriday, March 16, 2012 - 17:10
Many of the drugs given to prevent and treat asthma are inhaled. Inhaled medications do not have to be processed in any way by digestive organs in order to start working. Instead, they travel directly to the lungs, produce their effects quickly, and cause relatively few side effects.
Several different inhaler devices are available to suit the needs of different people with different kinds of asthma. All of them have their own advantages and disadvantages. Your doctor will decide which ones are best for you.
The basic kinds of inhaler delivery systems available for adults with asthma are:
The medication is contained in a small, pressurized canister that releases a pre-measured or "metered" dose. Most canisters hold around 200 individual doses, but 50-dose and 100-dose inhalers exist for some drugs.
The pressurized metered-dose inhaler (pMDI) is sometimes called a "puffer" because the medicine contained in it is delivered to the lungs as small "puffs".
A variety of asthma medications are available in MDI form, including preventer and reliever medications. They include:
- Preventer medications and other drugs used to control persistent asthma symptoms
- Reliever medications to treat symptoms of an asthma attack
The correct use of a "press and breathe" MDI takes practice and coordination between activating the MDI and breathing in at the right time to carry the drug into the lungs.
Most MDIs are pressurized by propellants called CFCs. CFCs are thought to contribute to depletion of the ozone layer and are being phased out in most countries. These substances are being replaced by non-CFC propellants that have a different taste and "feel" when they are sprayed into the mouth and throat. The newer MDIs also deliver a more gentle spray. These differences do not change the effectiveness of the asthma medication.
Correct inhaler technique is what delivers the medication to the lung, not the propellant used to power the device.
How do I use a metered-dose inhaler (MDI) without a spacer?
There are two basic ways of taking medication with an MDI without a spacer. Your doctor will tell you which of these methods you should use:
A spacer or holding chamber is a small container attached to the MDI as an extra device. Some MDIs (for example, Azmacort) have a built-in spacer.
- The spacer acts as a reservoir that changes the characteristics of the medication. The puff of medication from the MDI goes into the spacer where it "slows down" and turns into a very fine mist instead of a high pressure puff. This fine cloud of medication stays in the spacer until the person breathes in through a one-way valve, drawing the dose of medicine into the lung.
- The cloud of vapor is so fine that most people don't feel or taste it as they breathe in. The fine drug particles are carried deep into the lung where they do the most good, instead of hitting the tongue or the back of the throat the way a blast from an MDI sometimes does.
How do I use a metered-dose inhaler with a spacer?
Dry powder inhalers depend on the force of the air drawn into the lungs to pick up measured doses of the drug in the form of very small granules that are delivered to the lungs.
Some DPIs require very little effort to breathe in and be activated. Others require a greater effort and may not be suitable for everyone. Your doctor will decide if a DPI is best for you and, if so, which model to choose.
No coordination between activation of the unit and breathing in is required with DPIs, because they are "breath-activated." Your doctor will show you how to load and use your DPI.
Preventer medications and other drugs used to control persistent asthma symptoms that are available in DPI form include:
- Inhaled corticosteroids (such as budesonide)
- Long-acting beta2-bronchodilators (such as salmeterol and formoterol)
Reliever medications to treat symptoms of an asthma attack that are available in DPI form include:
- Short-acting beta2-bronchodilators (such as albuterol)
Multiple-dose and single-dose DPIs are available. Multidose-units offer convenience. Single-dose DPIs may be well-suited for children or adults where control of each individual dose is required:
Multidose DPIs include:
- Turbuhaler: 200-dose disposable unit with dose indicator; each dose is dispensed from a chamber when a knob on the base of the unit is rotated in one direction and then in the other.
- Diskus: 60-dose disposable unit with dose indicator; each dose dispensed from a dosing disc when a lever on the unit is moved.
- Diskhaler: 8-dose unit (Ventolin; Beclovent) and 4-dose unit (Serevent) with dose indicator; each dose dispensed from a dosing disk when the lid on the unit is raised, piercing a foil blister; replaceable medication disks
Single-dose DPIs include:
- Rotahaler: Rotating the sleeve of the unit breaks a capsule, releasing the powdered drug inside the unit; drug inhaled through fine mesh screen; reusable.
- Spinhaler: Sliding sleeve in and out punctures a drug capsule, releasing the powdered drug inside the unit; inhaling turns a small propeller that spins powdered drug out of the unit; reusable
- Aerolizer: Pressing two levers pierces a capsule. The capsule rotating during inhalation releases the powder into the air stream.
Which inhaler do I use during an asthma attack?
Inhalers are color-coded for the different drugs they contain. Different companies use different colors for their inhalers, but the color of the inhaler containing the reliever drug will always be different than the color used on the inhalers containing other asthma medications. Make note of the:
This awareness can be vitally important during the stress and anxiety of an asthma attack. Know which color inhaler contains your "rescue" medicine. Most companies use a blue color code on inhalers containing a short-acting beta2-bronchodilator to be used in an asthma emergency to relieve airway constriction.
Nebulizers consist of a small air compressor unit that turns liquid asthma medication into a fine mist that is breathed in through a mouthpiece. Treatments usually last around 10 minutes.
No coordination is required to deliver the medication because it is simply taken in with the breath. Compared with other inhalers, however, nebulizers are wasteful of drug. The units are compact but lack the convenience of portable MDIs and DPIs.
A limited number of medications are available in a form suitable for nebulizers.
Preventer medications and other drugs used to control persistent asthma symptoms that are available in nebulizer form are:
- Inhaled corticosteroids (such as budesonide)
- Nonsteroidal antiallergics (such as cromolyn)
Reliever medications to treat symptoms of an asthma attack that are available in nebulizer form are:
- Short-acting beta2-bronchodilators (many, such as albuterol)
- Anticholinergic bronchodilators (such as ipratropium)
How do I use a small-volume nebulizer?