The emerging role of tiotropium for patients with asthma

Emerging role of long-acting anticholinergics in children with asthma

PURPOSE OF REVIEW

Although the use of inhaled anticholinergics in obstructive airway disease has been established for several years, the clinical experience using these medications in treating patients with asthma is limited. Only few studies so far have included pediatric patients with asthma, but these studies demonstrate relevant therapeutic effects. This review will explore the pharmacological effects of inhaled anticholinergics, provide an overview about current adult and pediatric asthma studies using tiotropium, and describe future research needs.

RECENT FINDINGS

In a phase II study with tiotropium as add-on to maintenance treatment to inhaled corticosteroids (ICSs) in moderate persistent adolescent with asthma, significant improvement of peak and trough forced expiratory volume in 1 s (FEV1) with a good safety profile could be demonstrated. A pediatric phase II study in symptomatic patients with asthma aged 6-11with comparable study design also demonstrated significant improvement of peak FEV1 with no serious adverse events. However, both studies could not document a significant clinical improvement analyzed by standardized scores.

SUMMARY

Tiotropium might become an add-on treatment option in symptomatic pediatric and adolescent patients with asthma despite adequate therapy with ICS and long-acting β2-agonist (LABA) or as an alternative to LABA in patients with safety concerns related to LABA. For a better assessment of the clinical effect, long-term studies are needed.

Pharmacotherapy of critical asthma syndrome: current and emerging therapies

The critical asthma syndrome (CAS) encompasses the most severe, persistent, refractory asthma patients for the clinician to manage. Personalized pharmacotherapy is necessary to prevent the next acute severe asthma exacerbation, not just the control of symptoms. The 2007 National Asthma Education and Prevention Program Expert Panel 3 provides guidelines for the treatment of uncontrolled asthma. The patient's response to recommended pharmacotherapy is highly variable which risks poor asthma control leading to frequent exacerbations that can deteriorate into CAS. Controlling asthma symptoms and preventing acute exacerbations may be two separate clinical activities with their own unique demands. Clinicians must be prepared to use the entire spectrum of asthma medications available but must concurrently be aware of potential drug toxicities some of which can paradoxically worsen asthma control. Medications normally prescribed for COPD can potentially be useful in the CAS patient, particularly those with asthma-COPD overlap syndrome. Immunomodulation with drugs like omalizumab in IgE-mediated asthma syndromes is one important approach. New and emerging drugs address unique aspects of airway inflammation and biology but at a significant financial cost. The pharmacology and toxicities of the agents that may be used in the treatment of CAS to control asthma symptoms and prevent severe exacerbations are reviewed.

The acute management of asthma

Patients presenting to the emergency department (ED) or clinic with acute exacerbation of asthma (AEA) can be very challenging varying in both severity and response to therapy. High-dose, frequent or continuous nebulized short-acting beta2 agonist (SABA) therapy that can be combined with a short-acting muscarinic antagonist (SAMA) is the backbone of treatment. When patients do not rapidly clinically respond to SABA/SAMA inhalation, the early use of oral or parenteral corticosteroids should be considered and has been shown to impact the immediate need for ICU admission or even the need for hospital admission. Adjunctive therapies such as the use of intravenous magnesium and helium/oxygen combination gas for inhalation and for driving a nebulizer to deliver a SABA and or SAMA should be considered and are best used early in the treatment plan if they are likely to impact the patients' clinical course. The use of other agents such as theophylline, leukotriene modifiers, inhaled corticosteroids, long-acting beta2 agonist, and long-acting muscarinic antagonist currently does not play a major role in the immediate treatment of AEA in the clinic or the ED but is an important therapeutic option for physicians to be aware of and to consider initiating at the time of discharge from clinic, hospital, or ED to reduce later clinical worsening and readmission to the ED and hospital. A comprehensive summary is provided of the currently available respiratory pharmaceuticals approved for asthma and other airway syndromes. Clinicians must be prepared to use the entire spectrum of medications available for the treatment of acute asthma exacerbations and the agents that should be initiated to prevent worsening or additional exacerbations. They need to be familiar with the major potential drug toxicities associated with their use.

Role of anticholinergics in asthma management: recent evidence and future needs

PURPOSE OF REVIEW

Anticholinergic antimuscarinic bronchodilators play a major role in the treatment of chronic obstructive pulmonary disease, but their role in asthma has long been limited to acute management. More recently, the role of long-acting antimuscarinic bronchodilators (LAMAs) in chronic asthma management has been explored. This review will examine the pharmacological rationale for use of inhaled anticholinergics in the treatment of asthma, and provide an overview of the current literature supporting this use, as well as describe future research needs in this area.

RECENT FINDINGS

Short-acting anticholinergic bronchodilators have a role as add-on agents in the treatment of acute asthma. Preliminary clinical studies suggest that inhaled LAMAs may be comparable to long-acting beta2-agonists (LABAs) as an add-on therapy in patients not controlled by inhaled corticosteroids (ICS) alone, and may also have added benefit in patients not controlled on combined ICS-LABA. Mechanistic studies suggest that apart from their bronchodilator activity, LAMAs may have anti-inflammatory and antiremodeling influences on the airways. Further research is needed to clarify the clinical relevance of these experimental observations.

SUMMARY

Accumulating evidence supports the use of inhaled LAMAs as an add-on therapy in patients with asthma, who remain symptomatic despite guideline-based therapy with ICS with or without LABAs. Further studies are warranted to help define mechanisms of action of LAMAs, apart from their role as bronchodilators, and determine how these other actions impact asthma outcomes over time. Furthermore, future studies need to examine the long-term efficacy and safety of LAMAs in asthma and identify a subgroup of patients who would benefit from such therapies to facilitate early, personalized therapy.