Keys to therapeutic success include choosing the right device and drug regimen, providing rigorous patient education, and reducing environmental exposures.
Managing chronic obstructive pulmonary disease (COPD) presents a significant challenge to busy clinicians in many ways, especially when one is approaching the long list of inhaled pharmaceutical agents with an eye toward a cost-effective, patient-centered regimen. Inhaled agents remain expensive, with few available in generic form.
Our primary goal in this article is to detail these agents' utility, limitations, and relative cost. Specifically, we review why the following considerations are important:
* Choose the right delivery device and drug while considering patient factors.
* Provide patient education through allied health professionals.
* Reduce environmental exposures.
* Rethink the use of inhaled corticosteroids (ICS).
* Understand the role of dual therapy and triple therapy.
There are numerous other treatment modalities for COPD that are recommended in national and international practice guidelines, including vaccination, pulmonary rehabilitation, home visits, phosphodiesterase-4 inhibitors, oral glucocorticoids, supplemental oxygen, and ventilatory support. (1) Discussion of those modalities is beyond the scope of this review.
Pathophysiology and pharmacotherapy targets
COPD is characterized by persistent respiratory symptoms and airflow limitation, usually due to airway or alveolar abnormalities, or both, caused by environmental and host factors. (2) Sustained lung parenchymal irritation results from exposure to noxious fumes generated by tobacco, pollution, chemicals, and cleaning agents. Host factors include lung immaturity at birth; genetic mutations, such as alpha-1 antitrypsin deficiency and dysregulation of elastase; and increased reactivity of bronchial smooth muscles, similar to what is seen in asthma. (1)
Improving ventilation with the intention of relieving dyspnea is the goal of inhaler pharmacotherapy; targets include muscarinic receptors and beta 2-adrenergic receptors that act on bronchial smooth muscle and the autonomic nervous system. Immune modulators, such as corticosteroids, help reduce inflammation around airways. (1) Recent pharmacotherapeutic developments include combinations of inhaled medications and expanding options for devices that deliver drugs.
Delivery devices: Options and optimizing their use
Three principal types of inhaler devices are available: pressurized metered-dose inhalers (MDIs), dry-powder inhalers (DPIs), and soft-mist inhalers (SMIs). These devices, and nebulizers, facilitate medication delivery into the lungs (table 1 (3-9)).
Errors in using inhalers affect outcome. Correct inhaler technique is essential for optimal delivery of inhaled medications. Errors in technique when using an inhaled delivery device lead to inadequate drug delivery and are associated with poor outcomes: 90% of patients make errors that are classified as critical (ie, those that reduce drug delivery) or noncritical. (2) Critical inhaler errors increase the risk of hospitalization and emergency department visits, and can necessitate a course of oral corticosteroids. (10) Many critical errors are device specific; several such errors are described in TABLE 1. (3-9)
Patient education is necessary to ensure that drug is delivered to the patient consistently, with the same expectation of effect seen in efficacy studies (which usually provide rigorous inhaler technique training and require demonstration of proficiency). (1,2,10) For the busy clinician, a multidisciplinary approach, discussed shortly, can help. Guidelines developed by the Global Initiative for Chronic...