ReviewAnticholinergic agents in asthma and COPD
Introduction
Although naturally occurring anticholinergic alkaloids such as atropine and scopolamine have been used in traditional medical cultures for many years, these agents are well absorbed into the systemic circulation and thus have multiple systemic side-effects that limit their clinical usefulness. The discovery that synthetic quaternary congeners of atropine were very poorly absorbed but retained topical anticholinergic activity enabled the development of analogues of atropine such as ipratropium, oxitropium, and tiotropium bromides for clinical use as inhaled bronchodilators. In the last 2 decades, these agents have become important agents in the routine treatment of COPD but also for asthma in certain circumstances.
Section snippets
Available agents
In most countries, ipratropium bromide is available as a metered-dose inhaler, as a dry powder inhalation, and as a nebulizable solution as Atrovent®. Because the original dose of ipratropium, 40 μg, is suboptimal for COPD (Gross et al., 1989), a double strength metered-dose inhaler form, Atrovent forte®, is also available in many countries outside the USA. Fixed combinations of ipratropium with albuterol (salbutamol) are also available in metered-dose inhaler form as Combivent® and in
Stable COPD
The major clinical use of inhaled anticholinergic agents is for the routine treatment of stable COPD. Several large multi-center long-term clinical studies in the 1980s compared ipratropium metered-dose inhaler with a β-adrenoreceptor agonist metered-dose inhaler. These uniformly showed that the increase in Forced Expired Volume in 1 s (FEV1), the primary outcome of the studies, was at least as great and as prolonged with ipratropium as with a conventional β-adrenoreceptor agonist and sometimes
Side-effects and adverse events
Being very poorly absorbed, currently approved inhaled anticholinergic agents have a very wide therapeutic margin and are very well tolerated, even in rare instances when massive doses have accidentally been given (Gross and Skorodin, 1985). In normal clinical use, dryness of the mouth is a common side effect of all agents in this class but is rarely sufficiently severe for the patient to discontinue use. Bad taste is an occasional complaint, as is a brief coughing spell shortly after
References (33)
- et al.
Ba 679 BR, a novel long-acting anticholinergic bronchodilator
Life Sci.
(1993) Tiotropium bromide
Chest
(2004)- et al.
Massive overdose of atropine methonitrate with only slight untoward effects
Lancet
(1985) - et al.
The assessment and treatment of asthma: a conference report
J. Allergy Clin. Immunol.
(1990) - et al.
The addition of an aerosol anticholinergic to an oral beta agonist plus theophylline in asthma and bronchitis. A double-blind single dose study
Chest
(1982) - et al.
Nebulized anticholinergic and sympathomimetic treatment of asthma and chronic obstructive airways disease in the emergency room
Am. J. Med.
(1987) - et al.
A comparison of the bronchodilator activity of Sch 1000 and salbutamol
J. Allergy Clin. Immunol.
(1977) - et al.
The role of ipratropium bromide in the emergency management of acute asthma exacerbation: a meta-analysis of randomized clinical trials
Ann. Emerg. Med.
(1999) - et al.
Comparison of the anticholinergic bronchodilator ipratropium bromide with metaproterenol in chronic obstructive pulmonary disease. A 90-day multi-center study
Am. J. Med.
(1986) - et al.
Efficacy of atropine methylnitrate alone and in combination with albuterol in children with asthma
Chest
(1990)