October 2015
“Click” clinical initiatives, research and current updates in treatment
Review of Inhaled Medications for COPD Chris Henry, Epic Pharmacy Northside Chronic obstructive pulmonary disease (COPD) is very common in Australia and a major cause of disability, hospital admission and premature death.1 COPD is an umbrella term that includes emphysema, chronic bronchitis and chronic asthma.1 Asthma and COPD share a number of common traits and some patients will suffer from a combination of these conditions. The key distinguishing factor between these conditions is that airway dysfunction is mainly reversible in asthma; this is not the case with COPD.12 COPD cannot be cured or reversed, but rather the goal is optimal management. The Australian and New Zealand guidelines (known as “The COPD-X Plan”) summarise current evidence around optimal management of people with COPD. The guidelines state that when treating COPD, prescribers should:1 Confirm the diagnosis and assess severity Optimise function Prevent deterioration Develop a support network and encourage self-management Manage eXacerbations Optimal management of COPD follows a stepwise approach, guided by symptom severity.2
The introduction of new inhaled drugs and devices in recent years has the potential to cause confusion among consumers and healthcare providers. Up to 90% of patients use incorrect inhaler technique, resulting in inadequate drug deposition with the potential for increased exacerbations and unnecessary escalation of therapy.3 Inhaler technique should be reviewed as often as possible and the healthcare provider’s ability to demonstrate correct operation of any inhaler device is vital to ensure optimal therapeutic outcomes. There are currently in excess of 25 distinct inhalers available in Australia (Table 1), all of which can be divided into the following categories.
Pressurised Metered Dose Inhalers (pMDI) These “older generation” devices deliver medication in the form of an aerosol. The drug is mixed with a propellant in a metal canister and must be shaken before each use. The canister, housed in a plastic holder with mouth piece is depressed whilst the patient inhales in order to deliver the dose. Optimal technique with this device requires dexterity, hand strength and coordination.7 For individuals who struggle to coordinate inhalation and actuation, the pMDI can be used with a volumatic spacer. Alternatively, some drugs are also available in ‘breath-actuated’ inhalers which do
not require the same hand strength to press the canister, or the coordination to concurrently inhale.
Dry Powder Inhalers These devices deliver medication into the lungs in the form of a powder which can be either preloaded into a disposable device or provided in a capsule with a separate reusable device. The specific technique varies between each device in this class – consult the National Asthma Council4 and NPS MedicineWise5 websites for detailed instructions. However, some key points are consistent throughout these devices; do not exhale into the device or submerge when washing (the powder may cake when exposed to moisture); regularly check the dose counter and expiry, only clean the device with a tissue or dry cloth. Prescribers should consider the patient’s inspiratory flow strength before choosing one of these devices as they may not be a practical option for acutely unwell or frail patients.6 As with inhaler devices, there are an ever increasing number of inhaled drugs available to manage respiratory conditions. Fortunately, the newly approved drugs are essentially variations of existing drugs and can be summarised in the following three categories. For further details and resources see the Lung Foundation Australia website.13