Asthma and chronic obstructive pulmonary disease (COPD) are life-long, potentially life-threatening diseases that represent the leading chronic respiratory diseases in the world. Inhalation of medications is an effective method for rapidly delivering short- or long-acting bronchodilators and corticosteroids to prevent, control, and treat respiratory symptoms that accompany these diseases. 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.
Rescue inhalers that deliver short-acting bronchodilators to relieve sudden respiratory symptoms, and maintenance inhalers that deliver long-acting bronchodilators and corticosteroids to prevent and control respiratory symptoms, are the cornerstone of managing asthma and COPD. Inhalation devices that deliver these medications are available in four basic types:
Pressurized metered-dose inhalers (MDIs), which have been around for decades, 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 (breath-activated).
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.
The correct use of an inhaler depends on its type; thus, each manufacturer provides detailed instructions for use, some with a Medication Guide for consumers and/or a short online video to help visualize the technique. Unfortunately, up to 94% of patients with asthma and COPD use their inhalers incorrectly.2-4 Problems are not limited to one type of device, nor are they limited to patients—even healthcare professionals have made errors. Misuse leads to reduced efficacy and poor outcomes. For example, in a study published in 2015, Bonds et al. found that 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. While most of these errors typically result in diminished drug delivery rather than no delivery at all, other errors have resulted in omitted doses, overdoses, and exacerbation of the underlying disease and respiratory symptoms.
Common errors made by patients using any inhaler include:
Common errors made by patients using an MDI (with and without a spacer) include:
Common errors made by patients using a dry-powder, breath-activated inhaler include:
Common errors made by patients using a dry-powder inhaler that requires loading and piercing of a capsule prior to each dose include:
Over the past few years, several new devices for the administration of inhaled medications have been introduced. Some of the devices are used to administer newly marketed medications, while others contain previously available drugs in a different administration format. They were designed to address some of the problems with older inhalers and to improve the ability to use the inhalers correctly. Specifically, the newer inhalers include:
Despite these new design enhancements to improve correct use, unfamiliarity with the newer inhalers on the market has been the source of several recently reported errors.