Bronchodilator combination therapy for the treatment of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality, and its prevalence is rising worldwide. Bronchodilators remain the cornerstone of COPD treatment, especially inhaled β2-adrenergic receptor agonists and inhaled anticholinergics. Long-acting bronchodilators are considered more effective and convenient than short-acting bronchodilators for the maintenance treatment in patients with moderate to very severe COPD. There are currently 3 long-acting inhaled bronchodilators available in the United States: the β2-adrenergic receptor agonists formoterol and salmeterol, and the anticholinergic, tiotropium. All 3 long-acting bronchodilators have been shown to be effective and well tolerated for the management of patients with stable COPD in clinical studies. The combination of β2-adrenergic receptor agonists and anticholinergics has been shown to provide superior bronchodilatory effect than either agent alone, possibly because of different mechanisms of action of these agents. The current treatment guidelines recommend the use of one or more long-acting bronchodilators for patients with moderate to severe stable COPD who remain symptomatic with single-agent bronchodilator therapy. The objective of this article is to review clinical data on combined bronchodilator therapy with β2-adrenergic receptor agonists and anticholinergics in patients with COPD.     

Olodaterol + tiotropium bromide for the treatment of chronic obstructive pulmonary disease

A solid scientific rationale and an increasing body of clinical evidence for combining a β₂-agonist with an antimuscarinic agent in COPD fully support the opinion that patients not controlled by a single bronchodilator should be given two bronchodilators with different mechanisms of action. Tiotropium is an established choice for the management of patients with stable COPD, and olodaterol is a new effective and safe once-daily long-acting β2-agonist. The parallel bronchodilating modes of action of olodaterol and tiotropium make them an attractive combination in COPD. The large ongoing TOviTO Phase III trial program is documenting the efficacy and safety of olodaterol/tiotropium fixed dose combination delivered via the Respimat Soft Mist Inhaler as maintenance therapy in patients with moderate to very severe COPD. However, we must still know whether this fixed-dose combination will affect exacerbations and hospitalizations, and ultimately death, and also the precise estimates of its relative cardiovascular safety.     

Tiotropium bromide: a novel once-daily anticholinergic bronchodilator for the treatment of COPD

Tiotropium bromide (Spiriva, BA679BR, Boehringer Ingelheim) is a novel inhaled, long-acting anticholinergic bronchodilator that is employed as a once-daily maintenance treatment for patients with chronic obstructive pulmonary disease (COPD). Like ipratropium bromide, tiotropium bromide is a quaternary ammonium derivative that binds to muscarinic receptors. However, although tiotropium binds with high affinity to muscarinic receptors of M1-, M2- and M3-subtypes, it dissociates very slowly from M1- and M3-receptors but more rapidly from M2-receptors, thereby giving it a unique kinetic selectivity. To date, the short-acting anticholinergic agents ipratropium and oxitropium bromide have been extensively employed as bronchodilator therapy for patients with COPD. Indeed, the Global Initiative for Chronic Obstructive Lung Disease (GOLD) strategy emphasises the role of bronchodilators in symptomatic management of all stages of COPD. It is encouraging that tiotropium given once daily from a dry powder inhaler at 18 g has been shown to cause greater improvement in lung function and reduction in symptoms than ipratropium bromide given four times daily. Furthermore, clinical studies over a 1-year period have demonstrated that tiotropium has impressive and maintained effects on lung function, symptoms and health-related quality of life, and may also reduce exacerbations. In a recent large scale comparative study over 6 months, tiotropium has been shown to cause superior bronchodilation and symptomatic improvement when compared to twice daily salmeterol in COPD. The only significant reported adverse event is dry mouth, which is found in approximately 10%-15% of subjects, but this is reversible and rarely causes discontinuation of therapy. Based on these promising features, it is likely that tiotropium used alone or in combination with other bronchodilators will emerge as first-line maintenance treatment for patients with airway obstruction due to COPD.     

Indacaterol. A long-acting beta-2 agonist, no advantages in COPD

In patients with chronic obstructive pulmonary disease (COPD), bronchodilator drugs have only modest symptomatic efficacy. There is no evidence that they slow disease progression. A short-acting beta-2 agonist such as salbutamol is the first-choice treatment, used either on demand or on a regular basis. Long-acting beta2 agonists are an option for patients with nocturnal symptoms. Indacaterol is a long-acting beta-2 agonist that is inhaled once a day. Indacaterol has not been compared with a short-acting beta-2 agonist. Clinical evaluation is based on 4 double-blind randomised placebo-controlled trials, 3 of which also included a group treated with another long-acting bronchodilator (formoterol, salmeterol or tiotropium. The symptomatic efficacy of indacaterol was only modest, and similar to that of other long-acting bronchodilators. Indacaterol has the known adverse effect profile of beta-2 agonists. Some adverse effects seem to be more frequent than with other long-acting bronchodilators, including post-inhalation cough, hyperglycaemia, respiratory tract infections, and possibly cardiac disorders. There is no evidence that once-daily inhalation has any advantages over twice-daily inhalation, even in terms of convenience. In addition, as efficacy is limited, there is a risk that patients will use the drug more frequently, resulting in additional adverse effects. The nebulizer used to inhale the powder in the capsules is similar to the one provided with Foradil (formoterol. In practice, indacaterol offers no therapeutic advantage over existing treatments for patients with COPD. It is better to use the best-documented drugs and, if necessary, to add non-drug measures. Eliminating exposure to toxic agents, especially tobacco smoke, remains the only treatment with a proven benefit on the course of COPD.     

β(2) -adrenoceptor agonists: current and future direction

Despite the passionate debate over the use of β(2) -adrenoceptor agonists in the treatment of airway disorders, these agents are still central in the symptomatic management of asthma and COPD. A variety of β(2) -adrenoceptor agonists with long half-lives, also called ultra long-acting β(2) -adrenoceptor agonists (ultra-LABAs; indacaterol, olodaterol, vilanterol, carmoterol, LAS100977 and PF-610355) are currently under development with the hopes of achieving once-daily dosing. It is likely that the once-daily dosing of a bronchodilator would be a significant convenience and probably a compliance-enhancing advantage, leading to improved overall clinical outcomes. As combination therapy with an inhaled corticosteroid (ICS) and a LABA is important for treating patients suffering from asthma, and a combination with an inhaled long-acting antimuscarinic agent (LAMA) is important for treating COPD patients whose conditions are not sufficiently controlled by monotherapy with a β(2) -adrenoceptor agonist, some novel once-daily combinations of LABAs and ICSs or LAMAs are under development.     

Tiotropium bromide

Tiotropium bromide is a new long-lasting anticholinergic drug which, like ipratropium bromide, is a quaternary ammonium derivative. It binds with high affinity to muscarinic receptors but dissociates very slowly from M(1)- and M(3)-muscarinic receptors. Pharmacology studies have demonstrated a prolonged protective effect against cholinergic agonists and cholinergic nerve stimulation in animal and human airways. In Phase II studies single inhaled doses of tiotropium bromide have a bronchodilator and bronchoprotective effect in asthmatic and chronic obstructive pulmonary disease (COPD) patients of over 24 h. In Phase III studies, once daily inhaled tiotropium is an effective bronchodilator in COPD patients, giving great improvement in lung function and reduction in symptoms than ipratropium bromide given four times daily. The drug is well-tolerated and the only side effect of note is dryness of the mouth which occurs in approximately 10% of patients. Since, anticholinergics are the bronchodilators of choice in COPD it is likely that tiotropium bromide will become the most widely used bronchodilator for COPD patients in the future.     

Long-acting beta 2-adrenoceptor agonists or tiotropium bromide for patients with COPD: is combination therapy justified?

Bronchodilators are the mainstay of therapy for patients with established chronic obstructive pulmonary disease (COPD) but, at present, the majority of patients use short-acting agents. There is increasing evidence that long-acting agents, such as the beta(2)-adrenoceptor agonists salmeterol and formeterol, and the new anticholinergic tiotropium bromide provide a better therapeutic option. In the treatment of COPD, long-acting beta(2)-adrenoceptor agonists (LABAs) given twice daily cause the same degree of bronchodilation as tiotropium bromide given once daily. Combined use of an inhaled LABA with tiotropium bromide should provide important therapeutic benefits, as these drugs have distinct and complementary pharmacological actions in the airways. Although clinical trials of this combination have not been performed, clinical experience with Combivent, a combination of a short-acting beta(2)-adrenoceptor agonist (salbutamol) and a short-acting anticholinergic (ipratropium bromide), in COPD is encouraging because the bronchodilation produced is of a magnitude greater than that of either component alone. However, because LABAs are given twice daily but tiotropium bromide is required only once daily, the challenge is to develop a combined inhaler that can be employed on a daily basis.     

Safety and pharmacological profile of tiotropium bromide

Background: Chronic obstructive pulmonary disease (COPD) is associated with progressive airflow obstruction and is characterized by a high risk of morbidity and mortality. With early detection and treatment, the natural history of this disease may be improved. So far, bronchodilator therapy is the most important treatment for COPD. Tiotropium is a bronchodilator of recent introduction. Objective: To discuss the clinical data on the safety and efficacy of tiotropium, a very long-acting antimuscarinic drug, available at present. Methods: The Cochrane trial database, Medline, Embase, were searched systematically, and ～ 20 respiratory journals and conference abstracts were searched manually. Language of publication was limited to English. included tiotropium, COPD, anticholinergic, safety and adverse events. Conclusion: A large body of evidence is available at present on the safety and efficacy of tiotropium in COPD, with dry mouth being the most common adverse event. Reviews of serious adverse event data in the literature have reported that tiotropium is safe and that the incidence of these events is the same as with placebo. Tiotropium is a convenient treatment for COPD with a good clinical efficacy and safety profile.     

Tiotropium bromide, a new, once-daily inhaled anticholinergic bronchodilator for chronic-obstructive pulmonary disease

Tiotropium bromide is a quaternary ammonium compound structurally related to ipratropium and has recently been approved in the US for the long-term, once-daily, maintenance treatment of bronchospasm associated with chronic-obstructive pulmonary disease (COPD). It is available in a dry powder form, where 18 microg [corrected] of the drug is inhaled once-daily through a device, the HandiHaler). The potency and long duration of effect of this anticholinergic bronchodilator result primarily from a prolonged blockade of the M1 and M3 muscarinic receptors in the airways and a relatively more rapid dissociation from the M2 receptor (which provides inhibitory feedback). Multiple studies of up to a duration of 1 year have demonstrated its effectiveness as a bronchodilator for COPD, with a trough increase (measured approximately 24 h after administration of the drug) in forced expiratory volume in 1 s of approximately 0.12 l and a peak increase of approximately 0.25 l. Tiotropium inhalation also leads to a significant reduction in static lung volumes in hyperinflated patients with COPD; this probably contributes to the reduction in dyspnoea that is associated with long-term use of this maintenance bronchodilator. Regular use of the drug was associated with clinically meaningful increases in the Transitional Dyspnoea Index, which indicate reductions in dyspnoea associated with daily activities. Improvement in the respiratory-specific health status questionnaire, the St George's Respiratory Questionnaire component and total scores was also documented. Finally, pooled data from two 1-year studies and two 6-month studies documented 20 and 28% reductions in the number of exacerbations per patient per year. Side effects have been relatively minimal, with dry mouth the most common symptom, ranging 6 - 16% of patients and rarely leading to discontinuation of the study drug. Limited comparisons of efficacy with other bronchodilators are available. Once-daily tiotropium has been demonstrated to be clearly superior to ipratropium four times daily as a bronchodilator for COPD. Combined results from two studies comparing once-daily tiotropium to twice-daily inhalation of standard doses of salmeterol, indicate a magnitude of the bronchodilator response similar in the two drugs early in the study. However, by 6 months, the bronchodilator effect of tiotropium was somewhat greater than that of the long-acting beta-agonist. Preliminary data suggest that combining tiotropium with long-acting beta-agonists may produce additional bronchodilator action in COPD.     

Tiotropium bromide

Tiotropium bromide is a new long-lasting anticholinergic drug which, like ipratropium bromide, is a quaternary ammonium derivative. It binds with high affinity to muscarinic receptors but dissociates very slowly from M₁- and M₃-muscarinic receptors. Pharmacology studies have demonstrated a prolonged protective effect against cholinergic agonists and cholinergic nerve stimulation in animal and human airways. In Phase II studies single inhaled doses of tiotropium bromide have a bronchodilator and bronchoprotective effect in asthmatic and chronic obstructive pulmonary disease (COPD) patients of over 24 h. In Phase III studies, once daily inhaled tiotropium is an effective bronchodilator in COPD patients, giving great improvement in lung function and reduction in symptoms than ipratropium bromide given four times daily. The drug is well-tolerated and the only side effect of note is dryness of the mouth which occurs in approximately 10% of patients. Since, anticholinergics are the bronchodilators of choice in COPD it is likely that tiotropium bromide will become the most widely used bronchodilator for COPD patients in the future.     

Tiotropium bromide,a new,once-daily inhaled anticholinergic bronchodilator for chronic-obstructive pulmonary disease

Tiotropium bromide is a quaternary ammonium compound structurally related to ipratropium and has recently been approved in the US for the long-term, once-daily, maintenance treatment of bronchospasm associated with chronic-obstructive pulmonary disease (COPD). It is available in a dry powder form, where 18 mg of the drug is inhaled once-daily through a device, the HandiHaler^®. The potency and long duration of effect of this anticholinergic bronchodilator result primarily from a prolonged blockade of the M₁ and M₃ muscarinic receptors in the airways and a relatively more rapid dissociation from the M₂ receptor (which provides inhibitory feedback). Multiple studies of up to a duration of 1 year have demonstrated its effectiveness as a bronchodilator for COPD, with a trough increase (measured ～ 24 h after administration of the drug) in forced expiratory volume in 1 s of ～ 0.12 l and a peak increase of ～ 0.25 l. Tiotropium inhalation also leads to a significant reduction in static lung volumes in hyperinflated patients with COPD; this probably contributes to the reduction in dyspnoea that is associated with long-term use of this maintenance bronchodilator. Regular use of the drug was associated with clinically meaningful increases in the Transitional Dyspnoea Index, which indicate reductions in dyspnoea associated with daily activities. Improvement in the respiratory-specific health status questionnaire, the St George’s Respiratory Questionnaire component and total scores was also documented. Finally, pooled data from two 1-year studies and two 6-month studies documented 20 and 28% reductions in the number of exacerbations per patient per year. Side effects have been relatively minimal, with dry mouth the most common symptom, ranging 6 – 16% of patients and rarely leading to discontinuation of the study drug. Limited comparisons of efficacy with other bronchodilators are available. Once-daily tiotropium has been demonstrated to be clearly superior to ipratropium four times daily as a bronchodilator for COPD. Combined results from two studies comparing once-daily tiotropium to twice-daily inhalation of standard doses of salmeterol, indicate a magnitude of the bronchodilator response similar in the two drugs early in the study. However, by 6 months, the bronchodilator effect of tiotropium was somewhat greater than that of the long-acting β-agonist. Preliminary data suggest that combining tiotropium with long-acting β-agonists may produce additional bronchodilator action in COPD.     

▾Indacaterol for COPD

?Indacaterol powder for inhalation (Onbrez Breezhaler - Novartis) is a long-acting beta(2) agonist, licensed for once-daily use as maintenance bronchodilator therapy for chronic obstructive pulmonary disease (COPD). In this article, we consider the evidence for indacaterol and how its use fits with current management strategies for COPD.     

UPLIFT Study: the effects of long-term therapy with inhaled tiotropium in chronic obstructive pulmonary disease

Background: In chronic obstructive pulmonary disease (COPD), inhaled tiotropium bromide, a long-acting anticholinergic, has been shown to exert a sustained bronchodilator effect and to be superior to ipratropium bromide, a short-acting formulation of the same pharmacological class. Objective: To discuss the effects of long-term therapy with tiotropium in COPD. Methods/results: Analysis of efficacy and safety data on tiotropium from a 4-year randomized placebo controlled study performed in moderate to very severe COPD patients. Tiotropium was found to reduce significantly COPD-related morbidity, to improve health-related quality of life (HRQoL) irrespective of disease severity and to slow significantly lung function decline in patients not using inhaled corticosteroids or other long-acting bronchodilators. The safety profile – and in particular cardiovascular safety – of tiotropium was good. Conclusions: Tiotropium bromide, alone or in combination with other inhaled therapies, can maintain an adequate control of COPD on a long-term basis.     

Seretide for obstructive lung disease

Seretide (Advair [North America], GlaxoSmithKline) is an inhaler combination formulation intended for the maintenance therapy of obstructive airways disease. Seretide was developed and made available initially as three multi-dose, dry powder inhaler formulations delivering 50 microg/puff of the long acting beta(2) agonist salmeterol and either 100, 250 or 500 microg/puff of the inhaled corticosteroid fluticasone propionate. In addition to the initial multi-dose dry powder inhaler system (Diskus or Accuhaler), a chlorofluorocarbon (CFC)-free pressurised aerosol formulation has become available. Studied mostly extensively as a maintenance therapy for patients with persistent asthma, the combination inhaler is at least equivalent to its components administered separately and is superior to monotherapy with salmeterol or inhaled corticosteroid in both paediatric and adult populations. The combination has a logical role in the treatment of moderate-to-severe asthma, offering the advantage of increased convenience and possibly improved compliance. In addition to improvements in lung function, symptom scores and quality of life, the combination therapy reduces exacerbation rates, an outcome that contributes to favourable cost-effectiveness. A role as initial maintenance therapy in all forms of persistent asthma is also plausible but there are fewer data concerning the impact of Seretide in milder forms of persistent asthma. Clinical trials are underway to examine the potential role of Seretide in patients with chronic obstructive pulmonary disease (COPD). Salmeterol has been shown to be an effective first-line bronchodilator in COPD and fluticasone has been shown to reduce the frequency and or severity of exacerbations in COPD patients in two key trials. At a time when the prevalence of both asthma and COPD is increasing, Seretide is a valuable step in the management of these common obstructive lung diseases.     

Comparative safety of long-acting inhaled bronchodilators: a cohort study using the UK THIN primary care database.

BACKGROUND: Use of a long-acting inhaled bronchodilator, either an anticholinergic or a beta-adrenergic receptor agonist (beta-agonist), is recommended for maintenance treatment of chronic obstructive pulmonary disease (COPD). In COPD, the organ system most frequently requiring medical care, other than the respiratory system, is the cardiac system. OBJECTIVES: To compare the risk of total mortality and certain respiratory and cardiac adverse events among users of the two types of recommended long-acting bronchodilators, we conducted a cohort study. Specifically, the study compared the safety of the only approved long-acting anticholinergic, tiotropium bromide, with the single-ingredient long-acting beta-agonists (LABAs) salmeterol or formoterol in a broad population of users. METHODS: We used automated general practitioner data from the UK THIN (The Health Information Network) database as the data source for this study. We used Cox proportional hazards models to compute hazard ratio (HR) estimates and 95% CI controlling for propensity scores comprising various baseline demographic variables, medical therapies and illnesses. RESULTS: The 1061 tiotropium users and 1801 LABA users were similar with regard to risk of total mortality (HR 0.93; 95% CI 0.59, 1.44) and most cardiac events, including angina (HR 0.77; 95% CI 0.37, 1.59), atrial fibrillation or flutter (HR 0.60; 95% CI 0.25, 1.42), myocardial infarction (HR 1.29; 95% CI 0.45, 3.66) and tachycardia (HR 0.66; 95% CI 0.29, 1.51). Though imprecise, there was evidence of a decreased risk of heart failure (HR 0.65; 95% CI 0.37, 1.12) in tiotropium users. As regards respiratory endpoints, the risk of COPD exacerbation (HR 1.15; 95% CI 0.79, 1.67) and pneumonia (HR 1.11; 95% CI 0.38, 3.26) were similar among users of each type of drug, although there was a decreased risk of asthma exacerbation (HR 0.41; 95% CI 0.26, 0.64) in tiotropium users compared with LABA users. CONCLUSIONS: Users of tiotropium and single-ingredient LABA had similar risk of total mortality and cardiovascular endpoints. The decreased risk of asthma exacerbations with tiotropium may be due to residual confounding by indication. Confidence limits for most events include reduced risks for tiotropium and also small increases in risk. Nevertheless, the point estimates suggest that tiotropium was associated with a lower risk of each cardiac event except myocardial infarction. However, the small number of cases means that further studies are needed to confirm these results.     

Long-acting muscarinic antagonists for the treatment of chronic obstructive pulmonary disease

Muscarinic acetylcholine receptor antagonists, particularly of the M(3) subtype, are useful therapeutics as bronchodilators in chronic obstructive pulmonary disease (COPD). The first long-acting muscarinic antagonist, tiotropium bromide (Spiriva(?)), was launched in 2002 and has since become established as the gold-standard muscarinic antagonist for the treatment of COPD. This review will survey the preclinical profiles of tiotropium and nine inhaled development candidates as well as literature reports of other preclinical compounds specifically designed as inhaled antimuscarinic agents for the treatment of COPD. The design strategies employed lay behind three common principles: high potency and slow reversibility at the M(3) receptor and low systemic exposure. In addition to their effectiveness as bronchodilators, the differentiation of these agents in the clinic may be linked to their potential to be utilized in combination with other therapeutics. In the long term, the emerging knowledge around the role of muscarinic antagonists in the inflammation and remodeling of the airways may also help in discriminating them.     

Pharmacology and therapeutics of bronchodilators

Bronchodilators are central in the treatment of of airways disorders. They are the mainstay of the current management of chronic obstructive pulmonary disease (COPD) and are critical in the symptomatic management of asthma, although controversies around the use of these drugs remain. Bronchodilators work through their direct relaxation effect on airway smooth muscle cells. at present, three major classes of bronchodilators, β(2)-adrenoceptor (AR) agonists, muscarinic receptor antagonists, and xanthines are available and can be used individually or in combination. The use of the inhaled route is currently preferred to minimize systemic effects. Fast- and short-acting agents are best used for rescue of symptoms, whereas long-acting agents are best used for maintenance therapy. It has proven difficult to discover novel classes of bronchodilator drugs, although potential new targets are emerging. Consequently, the logical approach has been to improve the existing bronchodilators, although several novel broncholytic classes are under development. An important step in simplifying asthma and COPD management and improving adherence with prescribed therapy is to reduce the dose frequency to the minimum necessary to maintain disease control. Therefore, the incorporation of once-daily dose administration is an important strategy to improve adherence. Several once-daily β(2)-AR agonists or ultra-long-acting β(2)-AR-agonists (LABAs), such as indacaterol, olodaterol, and vilanterol, are already in the market or under development for the treatment of COPD and asthma, but current recommendations suggest the use of LABAs only in combination with an inhaled corticosteroid. In addition, some new potentially long-acting antimuscarinic agents, such as glycopyrronium bromide (NVA-237), aclidinium bromide, and umeclidinium bromide (GSK573719), are under development, as well as combinations of several classes of long-acting bronchodilator drugs, in an attempt to simplify treatment regimens as much as possible. This review will describe the pharmacology and therapeutics of old, new, and emerging classes of bronchodilator.     

Potential for long-acting muscarinic antagonists in chronic obstructive pulmonary disease

Importance of the field: The prevention and relief of symptoms by regular use of bronchodilators is central to the pharmacological management of chronic obstructive pulmonary disease (COPD).

Areas covered in this review: The aim of this article is to review the effects of inhaled muscarinic antagonists in the treatment of stable COPD.

What the reader will gain: An update of the clinical studies performed with the long-acting inhaled muscarinic antagonist (LAMA) tiotropium bromide in patients with COPD is given. In recent years, combinations of a LAMA and a long-acting inhaled beta2-agonist (LABA), and ‘triple therapy’ consisting of a LAMA, a LABA, and an inhaled steroid are being developed. Issues of safety of inhaled anticholinergics in COPD are discussed and a short overview of new LAMAs being developed for COPD is given.

Take home messages: The importance of anticholinergic drug treatment in COPD was largely advanced by the development of the first LAMA, tiotropium bromide. The vast experience obtained with tiotropium bromide has paved the way for new LAMAs such as aclidinium bromide and glycopyrrolate (NVA-237).     

Tiotropium: an inhaled anticholinergic for chronic obstructive pulmonary disease.

PURPOSE: The pharmacology, pharmacokinetics, clinical efficacy, adverse effects, drug interactions, dosage and administration, and formulary considerations of tiotropium are discussed. SUMMARY: Tiotropium, a long-acting inhaled anticholinergic, recently received approval from the Food and Drug Administration for the management of chronic obstructive pulmonary disease (COPD). In patients with COPD, increased parasympathetic nervous system activity leads to bronchoconstriction and mucus secretion. Tiotropium induces relaxation of the airway smooth muscle, as does ipratropium, but differs in receptor association and dissociation rates, allowing for once-daily administration. After inhalation, tiotropium reaches maximal plasma concentrations within five minutes, but clinical improvements in forced expiratory volume in one second (FEV(1)) are maintained over 24 hours. Clinical trials of tiotropium with placebo, ipratropium, and salmeterol have demonstrated the efficacy of tiotropium in improving FEV(1) and forced vital capacity values and health-related quality of life. The most commonly observed adverse effect is dry mouth. No increase in adverse effects was observed when tiotropium was administered concomitantly with other drugs for COPD, including sympathomimetic bronchodilators and oral and inhaled corticosteroids. The combination of tiotropium and other anticholinergics has not been studied and is not recommended. The recommended dosage of tiotropium is the inhalation of an 18-mug capsule with a HandiHaler breath-actuated inhalation device once daily. CONCLUSION: Tiotropium appears to be at least as effective as currently available alternatives in the treatment of patients with COPD who require daily bronchodilator treatment. Its simplified dosing and tolerable adverse-effect profile can potentially lead to enhanced patient compliance.