Asthma and chronic obstructive pulmonary disease are life-long, potentially life-threatening diseases. Inhalation of medications is an effective method for delivering short- or long-acting bronchodilators and corticosteroids to prevent and control respiratory symptoms. Inhalation of medications may also reduce the risk of adverse drug effects because the medications can often be provided in lower doses than an oral form of the drug. There are four basic types of inhalers:
Pressurized metered-dose inhalers (MDIs) typically consist of a small canister of medication fitted into a plastic body with a mouthpiece. Each dose is delivered by pressing the canister into the plastic body while inhaling through the mouthpiece. Use of a "spacer" that connects to the MDI makes it easier to inhale the dose, which is first released into the spacer and then inhaled slowly.
Dry-powder, breath-activated inhalers are preloaded with the medication(s) inside the device. Prior to use, a single dose of the medication is loaded into the mouthpiece, often by turning or twisting the inhaler body until a "click" signals the dose is ready to be inhaled. Patients simply take a deep breath while their lips are sealed around the inhaler, and a single dose is delivered.
Dry-powder, capsule inhalers utilize capsules as the dose-holding system, which are inserted into the device by the manufacturer or by the patient prior to use, and punctured by the device before each dose is inhaled directly from the inhaler.
Soft mist inhalers are a propellant-free liquid inhaler that provides a slow-moving, soft aerosol cloud of medicine to help patients inhale the medication, even if they can't take a very deep breath.
Errors With Inhalers
The correct use of an inhaler depends on its type; thus, each manufacturer provides detailed instructions for use. Unfortunately, up to 94% of patients use their inhalers incorrectly. Problems are not limited to one type of device, nor are they limited to patients-even healthcare professionals make errors (Bonds et al., 2015). In the study by Bonds et al., only 7% of patients who used MDIs demonstrated proper technique; 93% made at least one mistake, and of those, 63% missed 3 or more steps in the 11-step process. Although most of these errors result in diminished drug delivery rather than no delivery, other errors have resulted in omitted doses and overdoses.
Common errors include:
* Not holding their breath long enough (10 seconds or as long as comfortable) after inhaling a dose
* Using an empty inhaler because the patient can still see or feel a "spray"
* Forgetting to exhale completely before each dose or exhaling into the inhaler
* Not using maintenance inhalers when asymptomatic
Common errors made by patients using an MDI include: not shaking the canister or container before each dose; inhaling at the wrong time (not in sync with pressing the inhaler); aiming the inhaler at the roof of the mouth or tongue, rather than the throat; inhaling an unnoticed foreign body that has entered an uncapped inhaler; damaged or sticky spacer valves that limit the delivery of the medicine.
Common errors made by patients using a dry-powder, breath-activated inhaler include: failing to load a dose before inhaling; loss of medication by holding the inhaler mouthpiece upside down during or after loading a dose; failure to inhale strongly enough.
Common errors made by patients using a dry-powder inhaler that requires loading and piercing of a capsule prior to each dose include:
* Not piercing the capsule
* Forgetting to remove the spent capsule and not using a new capsule for each dose
* Failing to take a second breath (if indicated) to receive the full dose
* Swallowing the capsule instead of inhaling its contents
* Placing the capsule into the inhaler mouthpiece instead of the chamber designed to hold the capsule, which can result in swallowing or choking on the capsule during inhalation (ISMP Canada, 2016; National Asthma Council Australia, 2008)
Errors With Newer Inhalers
Several new devices for the administration of inhaled medications have been introduced. Some of the devices are used to administer newly marketed medications, whereas others contain previously available drugs in a different administration format. They were designed to improve the ability to use the inhalers correctly. They include:
* A dose counter that allows patients to see when the supply of medication is low.
* A longer duration of spray at a lower speed to help patients receive the full dose despite problems with coordinating the spray with the breath and the depth of the breath.
* The inability to activate a dose when all of the medication has been used.
Unfamiliarity with these newer inhalers has been the source of some recently reported errors. A patient discharged from the hospital on SPIRIVA HANDIHALER was readmitted 3 days later after taking 3 Spiriva capsules by mouth each day rather than placed in the device so its contents could be inhaled. A color-blind patient was unable to tell if the indicator window on a TUDORZA PRESSAIR inhaler was red or green. The window turns green when the inhaler is loaded with a dose and ready to use, and red when the dose has been completely inhaled.
Optimal Use of Inhalation Devices
We have compiled a list of proactive risk-reduction strategies to support the proper use of these and other inhalers by patients and practitioners:
* Obtain demonstration inhalers from the manufacturer to provide hands-on education. Maintain these demonstration devices in a segregated area away from actual medications so they don't find their way into the supply for patients.
* Ensure that patient education includes a demonstration of how the inhalation device is to be used. Helpful how-to videos are available from the Centers for Disease Control and Prevention (http://www.ismp.org/sc?id=1759), the use-inhalers.com website (http://use-inhalers.com), and product-specific websites. The use-inhalers.com website also offers free handouts for patients with step-by-step instructions in both English and Spanish.
* Focus education on essential aspects of proper inhaler use and the importance of taking all doses, and place less emphasis on aspects of treatment that allow some flexibility, such as timing between BID or q12h doses.
* Remind patients to discard an inhaler when the dose counter is at zero, even if the device continues to spray.
* Ask the patient to demonstrate inhaler technique (using a demonstration inhaler or their own) to create opportunities to correct improper technique. For devices using capsules, emphasize the need to place the capsule in the piercing chamber and not in the mouthpiece, and that the capsules should never be swallowed.
* If patients are not responding to treatment as expected, observe their technique using inhalation devices to ensure proper delivery of the prescribed medications.
ISMP gratefully acknowledges ISMP Canada for providing most of the content for this article (ISMP Canada, 2016).
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