Tiotropium (Spiriva): mechanistical considerations and clinical profile in obstructive lung disease

Long-acting anticholinergic use in chronic obstructive pulmonary disease: efficacy and safety

PURPOSE OF REVIEW

This article reviews findings from recently published randomized controlled trials and systematic reviews to provide an up-to-date assessment of the efficacy and safety of tiotropium, the only currently available long-acting muscarinic antagonist, when used alone or in conjunction with other respiratory medications in the treatment of chronic obstructive pulmonary disease (COPD).

RECENT FINDINGS

Results of recent clinical trials support findings from earlier trials in patients with moderate to very severe COPD demonstrating significant benefits of tiotropium compared to placebo, including sustained increases in lung function, reductions in exacerbations and risk of exacerbation-related hospitalizations, and improvement in health status. These benefits were particularly noted in the 4-year UPLIFT study that included 5993 COPD patients, including a large percentage with moderate severity. Whereas the cardiovascular safety of tiotropium has been questioned, results of the UPLIFT trial and a recent pooled analysis of data from 30 trials of tiotropium demonstrated that tiotropium is associated with reductions in the risk of all-cause mortality, cardiovascular mortality and cardiovascular events.

SUMMARY

Recent findings confirm the benefits of tiotropium in COPD management and provide reassurance regarding its safety. Moreover, the recent UPLIFT trial provides supportive evidence for the efficacy of tiotropium in COPD patients already receiving treatment with long-acting inhaled beta-agonists and inhaled corticosteroids, suggesting advantages of 'triple' therapy in advanced disease. Further, well designed, adequately powered studies should explore the potential advantages and disadvantages of various combinations of currently available long-acting respiratory medications in COPD, particularly in different clinical phenotypes of this heterogeneous disease.

Paradoxical trough effects of triple therapy with budesonide/formoterol and tiotropium bromide on pulmonary function outcomes in COPD

BACKGROUND

Lowest receptor occupancy for a drug occurs at trough prior to the next dose. Previous studies have focused on the effects of triple therapy at peak dose intervals using forced expiratory maneuvers. Impulse oscillometry (IOS) and body plethysmography (PLETH) are more sensitive than spirometry to assess inhaled therapies in COPD.

METHODS

Nineteen patients with COPD (FEV(1)/FVC ratio < 0.7; FEV(1) < 60%) completed a double-blind randomized crossover trial of tiotropium 18 microg/d or placebo for 2 weeks each, with a 1-week washout. Prior to this procedure, there was a nonrandomized 4 week run-in of budesonide/formoterol 200/6 2 puffs bid, which continued throughout the study. Spirometry, IOS, and PLETH were performed both before pre- and post-budesonide/formoterol run-in and at trough following the first and last dose of tiotropium (ie, 24 h posttiotropium and 12 h post-budesonide/formoterol).

RESULTS

Mean +/- SEM for age and FEV(1) were 65 +/- 2 years and 42 +/- 2%, respectively. Following initial budesonide/formoterol, there were no significant changes in spirometry; however, all measures of IOS and PLETH deteriorated (P < .01 for all outcomes). Compared with placebo, tiotropium was additive to budesonide/formoterol after single and chronic dosing measured by FEV(1) (P < .001 and P = .014, respectively) and forced expiratory flow, midexpiratory phase (P = .001; P= .026), whereas specific airway resistance, reactance, resonant frequency, and area under the reactance curve showed additive benefits at a single dose only.

CONCLUSIONS

Budesonide/formoterol caused an unexpected worsening of IOS and PLETH outcomes compared with a washed-out baseline in the nonplacebo-controlled run-in. This finding was not observed with spirometry. Subsequent addition of tiotropium improved lung function with all techniques after a single dose and for spirometry after chronic dosing. These paradoxical findings may reflect beta2-adrenoceptor downregulation and muscarinic 3 receptor cross talk. Placebo-controlled studies are required to explore this result.

Transport of ipratropium, an anti-chronic obstructive pulmonary disease drug, is mediated by organic cation/carnitine transporters in human bronchial epithelial cells: implications for carrier-mediated pulmonary absorption

Ipratropium bromide, an anticholinergic drug used for the treatment of asthma and chronic obstructive pulmonary disease, has low oral bioavailability, but systemic exposure, superior to oral administration, can be achieved by inhalation. Therefore, we investigated the pulmonary absorption mechanism of ipratropium using human bronchial epithelial BEAS-2B cells. [3H]Ipratropium uptake by BEAS-2B cells was temperature-dependent and saturable, with a K(m) value of 78.0 microM, suggesting involvement of carrier-mediated uptake. An RT-PCR study showed that organic cation/carnitine transporters OCTN1 and OCTN2 are expressed in BEAS-2B cells, but organic cation transporters (OCTs) are not. Uptake of [3H]ipratropium by HEK293 cells expressing OCTN1 (HEK293/OCTN1) and OCTN2 (HEK293/OCTN2) was significantly increased, compared with mock-transfected cells, and the estimated K(m) values were 444 microM and 53.0 microM, respectively. Finally, the contributions of OCTN1 and OCTN2 to ipratropium uptake were evaluated by measuring [3H]ipratropium uptake by BEAS-2B cells in which OCTN1 or OCTN2 gene expression had been silenced. Knock-down of OCTN1 or OCTN2 suppressed the uptake of [3H]ipratropium to 78.2% and 14.8% of that by control BEAS-2B cells, respectively. In addition, another anticholinergic, tiotropium, was also taken up by both HEK293/OCTN1 and HEK293/OCTN2 cells. Therefore, ipratropium and tiotropium are taken up primarily by OCTN2, and to a lesser extent by OCTN1, in bronchial epithelial cells. These findings are consistent with the pharmacological activity of the drugs after administration via inhalation.

Management of chronic obstructive pulmonary disease: moving beyond the asthma algorithm

For many years, chronic obstructive pulmonary disease (COPD) was considered a disease of fixed airflow obstruction for which there was no good treatment. Out of desperation and frustration, health care providers extrapolated from asthma to COPD, and standard asthma therapy was adopted without evidence for efficacy. In recent years, we have gained a better understanding of the pathophysiologic differences between asthma and COPD, and prospective controlled trials have provided a rationale for therapy. Smoking cessation is critically important, both as primary prevention and as an effective way to slow the decrease in lung function in patients with established disease. beta(2)-Adrenergic and anticholinergic agonists improve lung function and relieve symptoms in most patients. Tiotropium improves exercise tolerance and quality of life and reduces exacerbations and hospitalizations. The increase in lung function seen with tiotropium is sustained with continued use over at least 3 to 4 years. Inhaled corticosteroids decrease exacerbations and improve quality of life, and their effect seems greatest in patients with lower lung function and in exacerbation-prone patients. There is no evidence that inhaled corticosteroids alone affect mortality, despite the reduction in exacerbations and increased risk of pneumonia. In some patient populations, inhaled fluticasone, salmeterol, or the combination might slow the rate of loss of lung function. Rather than reflexively using effective asthma therapy in the patient with COPD, current and future therapy for COPD is increasingly evidence based and targeted to specific inflammatory pathways that are important in patients with COPD.

Anticholinergic treatment in airways diseases

The prevalence of chronic airways diseases such as chronic obstructive pulmonary disease and asthma is increasing. They lead to symptoms such as a cough and shortness of breath, partially through bronchoconstriction. Inhaled anticholinergics are one of a number of treatments designed to treat bronchoconstriction in airways disease. Both short-acting and long-acting agents are now available and this review highlights their efficacy and adverse event profile in chronic airways diseases.

Impact of frequency of COPD exacerbations on pulmonary function, health status and clinical outcomes

BACKGROUND

COPD exacerbations are responsible for the morbidity and mortality of this disease. The relationship between exacerbations and patient-related clinical outcomes is not clearly understood.

METHODS

A retrospective analysis of two 1-year, placebo-controlled clinical trials with tiotropium 18 microg daily was conducted to examine relationships between exacerbations and other clinical outcomes. The relationship between FEV(1), St. George's Respiratory Questionnaire (SGRQ), and the transition dyspnea index (TDI) were examined based on the frequency of exacerbations (0, 1, 2, >2).

RESULTS

921 patients participated in the trials (mean age 65 years, mean FEV(1) = 1.02 L (39% predicted). The percent change from baseline in FEV(1) in the tiotropium group was +12.6%, +12.0%, +2.1% and +8.9%; and in the placebo group was -3.4%, -3.4%, -5.7% and -6.7% for exacerbation frequencies of 0, 1, 2, >2, respectively. Compared with baseline, the largest improvement in SGRQ occurred in patients with no exacerbations. In the placebo group, there was a significant association between an increased frequency of exacerbations and worsening SGRQ scores. A reduction in exacerbation rates of 4.4% to 42.0% such as that shown in this study cohort was associated with meaningful changes in questionnaire based instruments.

CONCLUSIONS

In the placebo-treated patients increased frequency of exacerbations was associated with larger decrements in FEV(1), TDI, and SGRQ. A reduction in the frequency of exacerbations is associated with changes that are considered meaningful in these clinical outcomes.

SAR of a series of inhaled A(2A) agonists and comparison of inhaled pharmacokinetics in a preclinical model with clinical pharmacokinetic data

COPD is a major cause of mortality in the western world. A(2A) agonists are postulated to reduce the lung inflammation that causes COPD. The cardiovascular effects of A(2A) agonists dictate that a compound needs to be delivered by inhalation to be therapeutically useful. The pharmacological and pharmacokinetic SAR of a series of inhaled A(2A) agonists is described leading through to human pharmacokinetic data for a clinical candidate.

Tiotropium bromide: an update

Tiotropium bromide is a once-daily inhaled anticholinergic bronchodilator. It works by blocking the muscarinic receptors in airway smooth muscle. Tiotropium has a wide therapeutic margin, due to its poor gastrointestinal absorption and its very low systemic bioavailability. The drug is mainly indicated in COPD patients. Clinically relevant outcomes such as significant improvements in spirometry, hyperinflation, dyspnea, heath status, acute exacerbations and mortality have been consistently observed in tiotropium clinical trials, and the drug has been shown to reduce the risk of mortality due to cardiac-vascular disease and respiratory failure. The main side effect reported is dryness of the mouth. Some subgroups of asthmatics also seem to respond to anticholinergic drugs: among them, those with the Arg/Arg genotype for the beta2-adrenergic receptor and those with a high percentage of neutrophils in sputum.

Changes in lung function and health status in patients with COPD treated with tiotropium or salmeterol plus fluticasone

BACKGROUND AND OBJECTIVE

The effects of tiotropium, a long-acting anticholinergic drug, were compared with those of the combination of salmeterol, a long-acting beta(2)-agonist, and fluticasone, an inhaled corticosteroid, in patients with COPD.

METHODS

A 4-month, randomized, open cross-over study of tiotropium, 18 microg once daily, versus salmeterol, 50 microg, plus fluticasone, 200 microg, twice daily, was conducted in patients with COPD. Efficacy was assessed by spirometry and responses to the St George's Respiratory Questionnaire (SGRQ). After 4 months, patients were asked to select their subsequent therapy and indicate the reasons for their selection.

RESULTS

A total of 78 patients completed the study. There were no significant differences in the improvements in FEV(1) or SGRQ scores between the therapies. Similar numbers of patients selected tiotropium (42.3%) and salmeterol plus fluticasone (57.7%). However, those who preferred one of the therapies demonstrated greater improvements in SGRQ scores with that therapy. One subgroup of patients (30.8%) showed greater improvements in dyspnoea and FEV(1) in response to tiotropium, and the other subgroup of patients (35.9%) showed greater improvements in dyspnoea and FEV(1) in response to salmeterol plus fluticasone. Some patients (14.1%) selected salmeterol plus fluticasone because of positive effects on sputum expectoration.

CONCLUSIONS

The study was unblinded and the results need to be interpreted with caution. However, tiotropium and salmeterol plus fluticasone had similar overall effects on pulmonary function and SGRQ scores in patients with COPD. Responses to the two therapies were heterogeneous, and the patients who showed greater improvements in FEV(1) or SGRQ scores with one of the therapies preferred it for their subsequent treatment.

Optimizing bronchodilator therapy in emphysema

The treatment objectives for chronic obstructive pulmonary disease (COPD) include relieving symptoms such as dyspnea and cough, slowing the accelerated decline in lung function, decreasing exacerbations, and improving quality of life. All major guidelines for COPD management recommend beginning treatment with bronchodilators. There are several classes of bronchodilators, including beta-agonists, anticholinergics, and phosphodiesterase inhibitors, each with a specific mechanism of action. The overall approach to managing stable COPD involves a stepwise increase in treatment. Because of the progressive nature of emphysema, such an approach often involves combining bronchodilators from different pharmacologic classes. This review focuses on the pharmacologic properties of various bronchodilators and on recent studies that have examined combination therapy as a means to optimize treatment.

Similarities and differences in the autonomic control of airway and urinary bladder smooth muscle

The airways and the urinary bladder are both hollow organs serving very different functions, i.e. air flow and urine storage, respectively. While the autonomic nervous system seems to play only a minor if any role in the physiological regulation of airway tone during normal breathing, it is important in the physiological regulation of bladder smooth muscle contraction and relaxation. While both tissues share a greater expression of M2 than of M3 muscarinic receptors, smooth muscle contraction in both is largely mediated by the smaller M3 population apparently involving phospholipase C activation to only a minor if any extent. While smooth muscle in both tissues can be relaxed by beta-adrenoceptor stimulation, this primarily involves beta2-adrenoceptors in human airways and beta3-adrenoceptors in human bladder. Despite activation of adenylyl cyclase by either subtype, cyclic adenosine monophosphate plays only a minor role in bladder relaxation by beta-agonists; an important but not exclusive function is known in airway relaxation. While airway beta2-adrenoceptors are sensitive to agonist-induced desensitization, beta3-adrenoceptors are generally considered to exhibit much less if any sensitivity to desensitization. Gene polymorphisms exist in the genes of both beta2- and beta3-adrenoceptors. Despite being not fully conclusive, the available data suggest some role of beta2-adrenoceptor polymorphisms in airway function and its treatment by receptor agonists, whereas the available data on beta3-adrenoceptor polymorphisms and bladder function are too limited to allow robust interpretation. We conclude that the distinct functions of airways and urinary bladder are reflected in a differential regulation by the autonomic nervous system. Studying these differences may be informative for a better understanding of each tissue.

Effect of add-on therapy of tiotropium in COPD treated with theophylline

BACKGROUND

Although combination therapy with bronchodilators is recommended for chronic obstructive pulmonary disease (COPD), there is insufficient evidence for the efficacy of some combinations of long-acting bronchodilators.

OBJECTIVE

We investigated the effects of a combination therapy with tiotropium and theophylline in COPD patients.

METHODS

In a 12-week, open-labeled, parallel-group randomized study, pulmonary functions and dyspnea scores were compared between the combination and theophylline alone therapy at baseline, and 4 and 8 weeks after randomization in COPD.

RESULTS

Sixty-one COPD patients completed the trial (31 combination therapy, 30 theophylline alone; mean age 70 years; 58 males; mean dyspnea score 2.0 and forced expiratory volume in one second (FEV1) 1.5 L [62.5% predicted]). FEV1 in the combination group, but not in the theophylline alone, was significantly increased at 4 (1.56 +/- 0.13 L, p < 0.001) and 8 weeks (1.60 +/- 0.13 L, p < 0.001) from the baseline (1.40 +/- 0.12 L). In the combination group, but not the theophylline alone group, the dyspnea score was significantly improved after 4 (p < 0.01) and 8 weeks (p <0.05) compared with baseline. In 17 patients who did not receive theophylline at screening, treatment with 4 or 8 weeks of theophylline alone did not improve dyspnea score or FEV1.

CONCLUSION

Addition of tiotropium therapy to theophylline treatment can improve dyspnea and pulmonary function in COPD. Although this study did not assess whether there was any benefit of adding theophylline to patients treated with tiotropium, tiotropium can be a useful addition in COPD already treated with theophylline.

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.

Inhaled adenosine A(2A) receptor agonists for the treatment of chronic obstructive pulmonary disease

COPD is a major cause of mortality in the western world. A(2A) agonists are postulated to reduce the lung inflammation that causes COPD. The cardiovascular effects of A(2A) agonists dictate that a compound needs to be delivered by inhalation to be therapeutically useful. A strategy of minimizing side-effect liability by maximizing systemic clearance was followed and pharmacological and pharmacokinetic SAR of a series of inhaled A(2A) agonists described. A sevenfold improvement in potency and 150-fold reduction in side-effect liability over the lead compound CGS-21680, were obtained.

Equine recurrent airway obstruction and insect bite hypersensitivity: understanding the diseases and uncovering possible new therapeutic approaches

Recurrent airway obstruction (RAO) and insect bite hypersensitivity (IBH) are allergic conditions that are commonly encountered in the horse. Whilst complete allergen avoidance is an effective management strategy for both diseases, this may not be achievable in all cases and treatment options are therefore required. The inflammatory response is the main therapeutic target for glucocorticoids given to horses with RAO and severe cases of IBH, whilst the bronchodilators used in RAO primarily target airway smooth muscle. Such drugs are effective in most but not all individuals and there may be unwanted adverse effects. This article will review how knowledge of drug action and the pathogenesis of RAO and IBH can be utilised to identify potential targets for novel therapeutic agents that, in the longer term, may be safer and/or more effective in managing the allergic horse.

The combination of tiotropium and budesonide in the treatment of chronic obstructive pulmonary disease

Because additive effects of inhaled corticosteroids and long-acting anticholinergics are unclear, we undertook this study to compare the efficacy of tiotropium alone and tiotropium plus budesonide in patients with chronic obstructive pulmonary disease. The study subjects were randomized to receive either tiotropium 18 microg once daily with or without budesonide 200 microg twice daily for 6 weeks. The efficacy variables were changes in trough forced expiratory volume in one second (FEV1), St. George's Respiratory Questionnaire (SGRQ), 6-minute walk distance (6MWD), and use of rescue medication. One hundred patients were randomized and 81 completed the study. The mean age was 64.0 yr, and the mean FEV1 was 39.7% predicted. Compared with tiotropium alone (N=40), the tiotropium/budesonide combination (N=41) was related to an improvement in the SGRQ total score (tiotropium -2.8 units and tiotropium/budesonide -5.6 units, p=0.003). 6MWD was improved by 13.5 m in the tiotropium group and by 22.5 m in the tiotropium/budesonide group (p=0.031). Changes in trough FEV1 and the use of rescue medication were similar between two groups. In conclusion, compared with tiotropium alone, the tiotropium/budesonide combination was related to an improved health-related quality of life. These data support that low-dose budesonide may enhance the efficacy of tiotropium.

Chronobiology and chronotherapy of allergic rhinitis and bronchial asthma

Study of the chronobiology of allergic rhinitis (AR) and bronchial asthma (BA) and the chronopharmacology and chronotherapy of the medications used in their treatment began five decades ago. AR is an inflammatory disease of the upper airway tissue with hypersensitivity to specific environmental antigens, resulting in further local inflammation, vasomotor changes, and mucus hypersecretion. Symptoms include sneezing, nasal congestion, and runny and itchy nose. Approximately 25% of children and 40% of adults in USA are affected by AR during one or more seasons of the year. The manifestation and severity of AR symptoms exhibit prominent 24-h variation; in most persons they are worse overnight or early in the morning and often comprise nighttime sleep, resulting in poor daytime quality of life, compromised school and work performance, and irritability and moodiness. BA is also an inflammatory medical condition of the lower airways characterized by hypersensitivity to specific environmental antigens, resulting in greater local inflammation as well as bronchoconstriction, vasomotor change, and mucus hypersecretion. In USA an estimated 6.5 million children and 15.7 million adults have BA. The onset and worsening of BA are signaled by chest wheeze and/or croupy cough and difficult and labored breathing. Like AR, BA is primarily a nighttime medical condition. AR is treated with H1-antagonist, decongestant, and anti-inflammatory (glucocorticoid and leukotriene receptor antagonist and modifier) medications. Only H1-antagonist AR medications have been studied for their chronopharmacology and potential chronotherapy. BA is treated with some of the same medications and also theophylline and beta2-agonists. The chronopharmacology and chronotherapy of many classes of BA medications have been explored. This article reviews the rather extensive knowledge of the chronobiology of AR and BA and the chronopharmacology and chronotherapy of the various medications used in their treatment.

Cardiovascular and respiratory hospitalizations and mortality among users of tiotropium in Denmark

Tiotropium (Spiriva is an inhaled, once-daily anticholinergic medication for chronic obstructive pulmonary disease (COPD). We conducted a population-based cohort study to examine the risk of cardiovascular and respiratory hospitalizations and mortality with tiotropium. Using the Danish healthcare registries, we identified persons >/=40 years old in three counties who were hospitalized for COPD from 1/1/1977 to 12/31/2003. Respiratory and cardiovascular medications were assessed from dispensing records. Cox regression was used to compute incidence rate ratios (RR) and 95% confidence intervals (CI) for hospitalization and death between 1/1/2002 and 12/31/2003, associated with periods of tiotropium use compared to non-use, controlling for age, gender, time since COPD, concomitant respiratory and cardiovascular medications, prior hospitalizations and Charlson comorbidity index. Among persons with COPD (10,603), 75% were >/=60 years old. Follow-up was >/=18 months for 64%. Among those exposed to tiotropium compared to periods of non-use, the RR for total and cause-specific hospitalization endpoints were not elevated except for COPD hospitalization (RR = 1.52, 95% CI: 1.29, 1.79). Mortality endpoints included total mortality (RR = 0.77, 95% CI: 0.65, 0.91), respiratory mortality (RR = 0.79, 95% CI: 0.60, 1.04), sudden death (RR = 0.71, 95% CI: 0.21, 2.34), cardiac arrest (RR = 0.74, 95% CI: 0.42, 1.32), heart failure (RR = 0.84, 95% CI: 0.41, 1.75), and myocardial infarction (RR = 1.25, 95% CI: 0.49, 3.17). Compared to periods of non-use, tiotropium was associated with reduced respiratory and overall mortality and was not associated with increased cardiac mortality. An increase in COPD hospitalization is inconsistent with clinical trial data and suggests preferential prescribing due to disease severity.

1,5-Benzodioxepin derivatives as a novel class of muscarinic M3 receptor antagonists

The structure-activity relationships of novel 1,5-benzodioxepin derivatives as muscarinic M(1)-M(3) receptor antagonists are reported. Some of these compounds were found to possess high binding affinity for the muscarinic M(3) receptor and potent effect on rhythmic increase in bladder pressure in unanesthetized rats following oral administration. These compounds displayed selectivity for the bladder over the salivary gland.

Pooled clinical trial analysis of tiotropium safety

BACKGROUND

Marketing approval of pharmaceutical products is often based on data from several thousand subjects or fewer. Evaluation of safety is greatly enhanced by augmenting the safety database with postapproval studies.

METHODS

We conducted a pooled analysis of adverse event data from 19 randomized, double-blind, placebo-controlled trials with tiotropium in patients with obstructive lung disease. We computed incidence rates and rate ratios (RRs) for various reported adverse event end points of interest. Patients contributed person-time to the analysis as long as they were in the study until 30 days after treatment (tiotropium, placebo), or until they had the event of interest, whichever came first. Studies were pooled using the Mantel-Haenszel estimator, and we used 95% confidence intervals (CIs) to assess the precision of effect estimates.

RESULTS

The pooled trial population includes 4,435 tiotropium patients and 3,384 placebo patients contributing 2,159 person-years of exposure to tiotropium and 1,662 person-years of exposure to placebo. Dyspnea, dry mouth, COPD exacerbation, and upper respiratory tract infection were the most commonly reported events. There was a higher relative risk of dry mouth in the tiotropium group (RR, 3.60; 95% CI, 2.56 to 5.05). There was a lower risk of dyspnea (RR, 0.64; 95% CI, 0.50 to 0.81) and COPD exacerbation (RR, 0.72; 95% CI, 0.64 to 0.82) in patients receiving tiotropium compared to patients receiving placebo. Other results of interest are as follows: (1) all-cause mortality (RR, 0.76; 95% CI, 0.50 to 1.16); (2) cardiovascular mortality (RR, 0.57; 95% CI, 0.26 to 1.26); and (3) respiratory mortality (RR, 0.71; 95% CI, 0.29 to 1.74). The relative risk of urinary retention was 10.93 (95% CI, 1.26 to 94.88).

CONCLUSIONS

Pooling of adverse event data from preapproval and postapproval tiotropium clinical trials increase the precision of effect estimates and supports the present safety profile of tiotropium.

Use of tiotropium bromide for pre-operative treatment in chronic obstructive pulmonary disease patients: comparison with oxitropium bromide

OBJECTIVE

Chronic obstructive pulmonary disease (COPD), which ranks fifth in terms of the global burden of diseases, is one of the major risk factors of post-operative pulmonary complications. Tiotropium bromide is a new inhaled bronchodilator for COPD patients with a sustained duration of action; it has superior efficacy compared to other bronchodilators. However, little is known regarding its clinical value as a preoperative treatment for COPD patients. In this study, we compared the incidence of post-operative complications between COPD patients who received with tiotropium bromide and those who did not.

METHODS

Retrospective study.

PATIENTS

For 1 month before surgery we examined 84 and 82 patients treated with tiotropium bromide (tiotropium group) and oxitropium bromide (oxitropium group), respectively, in combination with other medications. We performed a statistical comparison of clinical features, pulmonary functions, and postoperative complications between the 2 groups.

RESULTS

The improvements in clinical symptoms and forced expiratory volume in 1 second were better in the tiotropium group than in the oxitropium group. The incidence of post-operative pulmonary complications (refractory bronchospasm, pulmonary infection, and acute respiratory failure) was significantly lower in the tiotropium group than in the oxitropium group. Three patients in the tiotropium group complained of dry mouth; however, the symptoms could be controlled. The incidence of post-operative non-pulmonary complications was not significantly different between the 2 groups.

CONCLUSION

We propose that tiotropium bromide might be a safe and useful drug for pre-operative treatment of COPD patients.

Highly sensitive assay for tiotropium, a quaternary ammonium, in human plasma by high-performance liquid chromatography/tandem mass spectrometry

Tiotropium bromide, a long-acting inhaled bronchodilator analogous to ipratropium bromide, is currently undergoing development for the treatment of chronic obstructive pulmonary disease. To evaluate its systemic absorption in humans, we have developed a rapid and sensitive method for its determination in human plasma based on high-performance liquid chromatography with tandem mass spectrometric detection (HPLC/MS/MS). Reversed-phase chromatography of tiotropium and the internal standard clenbuterol was carried out using acetonitrile/10 mM ammonium acetate (1% formic acid) 40:60 as mobile phase in a run time of 3.0 min. The sample preparation involved deproteination with acetonitrile, extraction into dichloromethane and back-extraction into hydrochloric acid. The assay was linear over the concentration range 0.500-50.0 pg/mL with intra- and inter-day precision (as relative standard deviation) both <or=7.34%. The method was successfully applied to a pharmacokinetic study of systemic absorption in healthy male volunteers given a single 18 microg inhaled dose.

The development of anticholinergics in the management of COPD

Anticholinergics have been used to treat obstructive respiratory disease for many years from historical preparations of the deadly nightshade genus, to the more recent developments ofipratropium, oxitropium, and tiotropium. The medical treatment of airways obstruction has focused on achieving maximal airway function through bronchodilators. Of the two main bronchodilators, beta2-agonists are often the first treatment choice although there is evidence of equivalence and some suggestions of the superiority of anticholinergics in chronic obstructive pulmonary disease (COPD). The following review looks at the background of anticholinergics, their pharmacological properties, and the evidence for use with suggestions for their place in the treatment of COPD.

Comparable spirometric efficacy of tiotropium compared with salmeterol plus fluticasone in patients with COPD: a pilot study

BACKGROUND

International guidelines recommend the long-acting anticholinergic, tiotropium, or long-acting beta 2-agonists as maintenance therapy in patients with moderate-to-very severe chronic obstructive pulmonary disease (COPD). The efficacy of long-acting beta(2)-agonists combined with inhaled corticosteroids (ICS) in the treatment of COPD has also been confirmed for severe and very severe COPD, but data comparing tiotropium with the combination of a long-acting beta 2-agonist and an ICS are lacking.

METHODS

This 6-week multicentre, randomised, double-blind, triple-dummy pilot study compared the bronchodilator effects of tiotropium 18 microg once daily (n=56) vs. the combination of salmeterol 50 microg plus fluticasone 250 microg twice daily (n=51) in patients with moderate-to-very severe COPD. Serial spirometry was performed over 12h after 6 weeks of treatment. The primary endpoint was forced expiratory volume in 1s (FEV1) area under the curve from 0 to 12h (AUC0-12h) on Day 43.

RESULTS

Randomization failed to provide treatment groups with comparable baseline characteristics for smoking history, current smokers, duration of COPD, FEV1, forced vital capacity (FVC) and reversibility. Mean+/-SD FEV1 was 1.31+/-0.47 l in the tiotropium group vs. 1.46+/-0.53 l in the salmeterol plus fluticasone group. Fewer patients in the tiotropium showed a 12% and 200 ml acute increase to short-acting bronchodilators at baseline. However, treatment with tiotropium alone resulted in comparable bronchodilation compared with salmeterol plus fluticasone, as measured by all the spirometric parameters at the end of the 6-week study period. FEV1 AUC0-12h was 1.55+/-0.03 l in the tiotropium group vs. 1.57+/-0.04 l in the salmeterol plus fluticasone groups (p=0.63). Trough (predose) FEV1 was 1.54+/-0.03 l in the tiotropium group vs. 1.46+/-0.03 l in the combination group (p=0.07), and peak FEV(1) was 1.68+/-0.04 l vs. 1.66+/-0.04 l, respectively, (p=0.77). FVC AUC0-12h, trough and peak were also comparable between groups at study end (p>0.05, for all). Further, rescue salbutamol use was similar in the tiotropium and combination groups and both treatment regimens were well tolerated.

CONCLUSIONS

Six weeks of treatment with tiotropium resulted in comparable bronchodilation compared with salmeterol plus fluticasone in patients with moderate-to-very severe COPD, despite tiotropium patients having lower lung function and fewer patients considered reversible at baseline. The results of this pilot study will aid planning for further large-scale comparative studies.

Additive benefits of tiotropium in COPD patients treated with long-acting β2 agonists and corticosteroids

OBJECTIVE AND BACKGROUND

The addition of an alternative class of long-acting bronchodilator is recommended for COPD patients who do not respond satisfactorily to monotherapy. The aim of this study was to investigate the additive benefit of tiotropium in severe COPD and to establish whether the improvement in lung function in these patients can be predicted from their acute bronchodilator response to ipratropium or salbutamol.

METHODOLOGY

Forty-six patients with severe COPD treated with inhaled long-acting beta(2) agonists and corticosteroids (LABA/CS) were enrolled. Their prebronchodilator FEV(1) was less than 50% of the predicted value. Tiotropium (18 microg, once daily) was added via a dry-powder inhaler device. After a month of treatment, tiotropium was stopped but their previous medication was continued. Patients were reassessed a month later. Acute bronchodilator response to ipratropium and salbutamol was assessed prior to tiotropium treatment. Pulmonary function and health status were evaluated.

RESULTS

Adding tiotropium significantly improved FVC, FEV(1) and inspiratory capacity (IC). The increase in FVC was significantly associated with an increase in IC (r = 0.36, P = 0.019) and a decrease in residual volume (r =-0.56, P < 0.001). Total scores of St. George Respiratory Questionnaire scores were significantly improved after adding tiotropium treatment (P < 0.001). After tiotropium withdrawal, FVC, FEV(1) and IC decreased markedly. Bronchodilator response to ipratropium did not predict the tiotropium-mediated improvement in FEV(1) or FVC.

CONCLUSIONS

Adding tiotropium to inhaled LABA/CS can yield clinical benefits in lung function and improved quality of life in COPD patients, as both drugs act through separate yet complementary pathways to maintain airway calibre.

Muscarinic receptors mediate stimulation of human lung fibroblast proliferation

Airway remodeling is a structural alteration associated with chronic inflammatory and obstructive airway diseases, wherein fibroblasts are crucially involved. The present study investigates whether lung fibroblast proliferation is influenced by muscarinic mechanisms. For this purpose, expression of muscarinic receptors in MRC-5 human lung fibroblasts was characterized by semiquantitative RT-PCR, and the effects of muscarinic agonists and antagonists on ((3)H)-thymidine incorporation as a measure of proliferative activity were studied under different culture conditions. MRC-5 fibroblasts express mRNA encoding different subtypes of muscarinic receptors (M(2) > M(3) > M(4), traces for M(5) and no M(1)). Expression of M(2) and M(3) receptors was confirmed at the protein level by immunoblot analysis. Under different culture conditions, carbachol (up to 10 microM) or oxotremorine (10 microM) stimulated ((3)H)-thymidine incorporation, with maximum increases between about 40 and 100%. The stimulatory effect of 10 microM carbachol was prevented by pretreatment with pertussis toxin and antagonized in a concentration-dependent manner by the muscarinic receptor antagonists tiotropium, AQ-RA 741, AF-DX 384, 4-diphenylacetoxy-N-methylpiperidine methoiodide, himbacine, p-fluorohexahydrosiladifenidol, and pirenzepine, with concentrations producing 50% inhibition of 14 pM, 24, 64, 127, 187, 452 nM, and 1.5 microM, respectively. Primary human lung fibroblasts were also found to express mRNA for muscarinic receptors (M(2) > M(1) > M(3), traces for M(4) and no M(5)), and showed a pertussis toxin-sensitive proliferative response to muscarinic receptor stimulation. In conclusion, proliferation of human lung fibroblasts can be stimulated by activation of muscarinic receptors with a pharmacologic profile correlating best to M(2) receptors.

Ipratropium bromide versus long-acting beta-2 agonists for stable chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a condition associated with high morbidity, mortality and cost to the community. Patients often report symptomatic improvement with long acting beta-2 agonists (LABAs) and anticholinergic bronchodilator medications, both of which are recommended in COPD guidelines. These medications have different mechanisms of action and therefore theoretically could have an additive effect when combined. As these medications are prescribed in COPD as long term therapy, it is important to assemble reliable evidence on their relative and additive effects.

OBJECTIVES

To compare the relative efficacy and safety of regular long term use (at least four weeks) of ipratropium bromide and LABA in patients with stable COPD. Comparisons were made between single agents and in combination versus LABAs alone.

SEARCH STRATEGY

We searched the Cochrane Airways Group Specialised Register of Trials (August 2005) and reference lists of articles. We also contacted drug companies for relevant trial data.

SELECTION CRITERIA

All randomised controlled trials comparing treatment for at least four weeks with an anticholinergic agent (ipratropium bromide) alone or in combination with LABA versus LABA alone, delivered via metered dose inhaler or nebuliser, in non-asthmatic adult subjects with stable COPD.

DATA COLLECTION AND ANALYSIS

Three review authors independently performed data extraction and study quality assessment. We contacted study authors and pharmaceutical companies for missing data.

MAIN RESULTS

Seven studies met the inclusion criteria of the review (2652 participants). Monotherapy comparison (six studies): There was a significantly greater change in favour of salmeterol in morning PEF and FEV1. There were no significant differences in quality of life, exacerbations, or symptoms. Formoterol appeared to confer some benefits over ipratropium treatment in terms of morning peak flow. Combination comparison (three studies): There was a significant improvement in post-bronchodilator lung function, supplemental short-acting beta-agonist use and HRQL in favour of combination therapy compared with salmeterol alone.

AUTHORS' CONCLUSIONS

The available data from the trials suggest that there is little difference between regular long term use of IpB alone and salmeterol if the aim is to improve COPD symptoms and exercise tolerance. However, salmeterol was more effective in improving lung function variables. In terms of post-bronchodilator lung function, combination therapy conferred modest benefits and a significant improvement in HRQL, and reduced supplemental short-acting beta-agonist requirement, although this effect was not consistent. Additional studies are needed to assess the relative effects of combining therapies, using validated subjective measurements, and should consider concordance and the convenience of people having to use different inhaler devices.

Tiotropium for stable chronic obstructive pulmonary disease: A meta-analysis

BACKGROUND

A systematic review was undertaken to evaluate the efficacy of tiotropium, a long acting anticholinergic drug, on clinical events, symptom scales, pulmonary function, and adverse events in stable chronic obstructive pulmonary disease (COPD).

METHODS

A systematic search was made of the Cochrane trials database, MEDLINE, EMBASE, CINAHL, and a hand search of 20 respiratory journals. Missing data were obtained from authors and the manufacturer. Randomised controlled trials of > or =12 weeks' duration comparing tiotropium with placebo, ipratropium bromide, or long acting beta2 agonists (LABA) were reviewed. Studies were pooled to yield odds ratios (OR) or weighted mean differences with 95% confidence intervals (CI).

RESULTS

Nine trials (8002 patients) met the inclusion criteria. Tiotropium reduced the odds of a COPD exacerbation (OR 0.73; 95% CI 0.66 to 0.81) and related hospitalisation (OR 0.68; 95% CI 0.54 to 0.84) but not pulmonary (OR 0.50; 95% CI 0.19 to 1.29) or all-cause (OR 0.96; 95% CI 0.63 to 1.47) mortality compared with placebo and ipratropium. Reductions in exacerbations and hospitalisations compared with LABA were not statistically significant. Similar patterns were evident for quality of life and symptom scales. Tiotropium yielded greater increases in forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) from baseline to 6-12 months than did placebo, ipratropium, and LABA. Decline in FEV1 over 1 year was 30 ml (95% CI 7 to 53) slower with tiotropium than with placebo and ipratropium (data were not available for LABA). Reports of dry mouth and urinary tract infections were increased with tiotropium.

CONCLUSIONS

Tiotropium reduced COPD exacerbations and related hospitalisations, improved quality of life and symptoms, and may have slowed the decline in FEV1. Long term trials are warranted to evaluate the effects of tiotropium on decline in FEV1 and to clarify its role compared with LABA.

Quantifying the association and dissociation rates of unlabelled antagonists at the muscarinic M3 receptor

Slow receptor dissociation kinetics has been implicated in the long clinical duration of action of the muscarinic receptor antagonist tiotropium. However, despite the potential benefits of new drugs with slow dissociation kinetics, the rate parameters of new compounds are seldom measured due to technical difficulties and financial implications associated with radiolabeling multiple ligands. Here we describe the development and optimisation of a medium throughput assay which is capable of measuring the kinetic parameters of novel, unlabelled compounds. Radioligand binding studies were performed with membranes derived from CHO cells recombinantly expressing the human M(3) muscarinic receptor.Initial characterisation of the radioligand [(3)H]-NMS yielded on and off rates of 4.1+/-0.2 x 10(8) M(-1) min(-1) and 0.015+/-0.0005 min(-1), respectively. The specific binding of [(3)H]-NMS was measured over time in the presence and absence of several concentrations of unlabelled competitor compounds. These data were analysed using a competition kinetic model to provide on and off rates for the unlabelled competitor. Comparison of the kinetically derived Kd (k(off)/k(on)) with K(i) values generated at equilibrium showed an excellent correlation (r(2)=0.99), providing good validation of the method. The on and off rates were also used in theoretical computer simulations to successfully predict the effect of incubation time on apparent IC(50) values. This study demonstrates that a medium-throughput competition kinetic binding assay can be used to determine accurate on and off rates of unlabelled compounds, providing the opportunity to optimise for kinetic parameters early in the drug discovery process.

Muscarinic receptor signaling in the pathophysiology of asthma and COPD

Anticholinergics are widely used for the treatment of COPD, and to a lesser extent for asthma. Primarily used as bronchodilators, they reverse the action of vagally derived acetylcholine on airway smooth muscle contraction. Recent novel studies suggest that the effects of anticholinergics likely extend far beyond inducing bronchodilation, as the novel anticholinergic drug tiotropium bromide can effectively inhibit accelerated decline of lung function in COPD patients. Vagal tone is increased in airway inflammation associated with asthma and COPD; this results from exaggerated acetylcholine release and enhanced expression of downstream signaling components in airway smooth muscle. Vagally derived acetylcholine also regulates mucus production in the airways. A number of recent research papers also indicate that acetylcholine, acting through muscarinic receptors, may in part regulate pathological changes associated with airway remodeling. Muscarinic receptor signalling regulates airway smooth muscle thickening and differentiation, both in vitro and in vivo. Furthermore, acetylcholine and its synthesizing enzyme, choline acetyl transferase (ChAT), are ubiquitously expressed throughout the airways. Most notably epithelial cells and inflammatory cells generate acetylcholine, and express functional muscarinic receptors. Interestingly, recent work indicates the expression and function of muscarinic receptors on neutrophils is increased in COPD. Considering the potential broad role for endogenous acetylcholine in airway biology, this review summarizes established and novel aspects of muscarinic receptor signaling in relation to the pathophysiology and treatment of asthma and COPD.

Ipratropium bromide versus short acting beta-2 agonists for stable chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a condition associated with high morbidity, mortality and cost to the community. Patients often report symptomatic improvement with short-acting beta-2 agonists (SABA) and anticholinergic bronchodilator medications, and both are recommended in COPD guidelines. These medications have different mechanisms of action and therefore could have an additive effect when combined.

OBJECTIVES

To compare the relative efficacy and safety of regular long term use (at least four weeks) of ipratropium bromide and short- acting beta-2 agonist therapy in patients with stable COPD.

SEARCH STRATEGY

The Cochrane Airways Group Specialised Register of Trials was searched. Bibliographies were checked to identify relevant cross-references. Drug companies were contacted for relevant trial data. The searches are current to August 2005.

SELECTION CRITERIA

All randomised controlled trials comparing at least 4 weeks of treatment with an anticholinergic agent (ipratropium bromide) alone or in combination with a beta-2 agonist (short acting) versus the beta-2 agonist alone, delivered via metered dose inhaler or nebuliser, in non-asthmatic adult subjects with stable COPD.

DATA COLLECTION AND ANALYSIS

Data extraction and study quality assessment was performed independently by three reviewers. Authors of studies and relevant manufacturers were contacted if data were missing.

MAIN RESULTS

Eleven studies (3912 participants) met the inclusion criteria of the review. Small benefits of ipratropium over a short-acting beta-2 agonist were demonstrated on lung function outcomes. There were small benefits in favour of ipratropium on quality of life (HRQL), as well as a reduction in the requirement for oral steroids. Combination therapy with ipratropium plus a short-acting beta-2 agonist conferred benefits over a short-acting beta-2 agonist alone in terms of post-bronchodilator lung function. There was no significant benefit of combination therapy in subjective improvements in HRQL, but again there was a reduction in the requirement for oral steroids.

AUTHORS' CONCLUSIONS

The available data from the trials included in this review suggest that the advantage of regular long term use of ipratropium alone or in combination with a short-acting beta-2 agonist or over a beta-2 agonist alone are small, if the aim is to improve lung function, symptoms and exercise tolerance. Until further data are available, the strategy of providing a short-acting beta-2 agonist on a PRN basis, and then either continuing with the short-acting beta-2 agonist regularly or conducting an "n of 1" trial of regular beta-2 agonist or regular anticholinergic to determine the treatment that gives the best relief of symptoms (and continuing with it), would seem cost effective. This strategy does need formal evaluation. Patient preference is also important, as is the relative importance of avoiding the use of systemic corticosteroids.

Absence of electrocardiographic findings and improved function with once-daily tiotropium in patients with chronic obstructive pulmonary disease

STUDY OBJECTIVES

To examine electrocardiographic findings after short- and long-term tiotropium therapy in patients with chronic obstructive pulmonary disease (COPD), and to establish previously reported symptomatic efficacy.

DESIGN

Randomized, double-blind, placebo-controlled, parallel-group study.

SETTING

Twelve outpatient investigational centers in the United States.

PATIENTS

One hundred ninety-six patients with COPD.

INTERVENTIONS

Patients received either tiotropium 18 mug once/day or placebo, delivered by the HandiHaler device.

MEASUREMENTS AND MAIN RESULTS

Electrocardiography (predose and 5 min postdose) and 24-hour Holter monitoring were performed at baseline and after 8 and 12 weeks of treatment with tiotropium 18 microg once/day or placebo. Efficacy measures (spirometry, global COPD ratings, scores on the EuroQol Health Questionnaire [EQ-5D], albuterol inhaler as needed) were included to demonstrate that the study population exhibited the characteristic improvements observed in previous tiotropium studies. Mean baseline forced expiratory volume in 1 second (FEV1) was 1.03 L. Mean changes in heart rate from baseline were similar in both groups. No differences were noted in the percentage of patients developing rhythm or conduction abnormalities detected with electrocardiography or Holter monitoring. Frequency of premature beats and mean maximal changes in PR, QRS, QT, QTcB, and QTcF intervals were similar in both groups. No patients developed new-onset QT or QTc intervals greater than 500 msec, and no differences were noted in the percentage of patients developing new QT prolongation less than 30 msec, 30-60 msec, or greater than 60 msec. At 12 weeks, predose and postdose improvements in FEV1 were 184 and 265 ml, respectively, with tiotropium versus placebo (p<0.001). Physician and patient global COPD ratings and the EQ-5D visual analog scale scores were improved with tiotropium (p<0.05); as-needed albuterol was reduced by 25% relative to placebo (p<0.05).

CONCLUSION

Tiotropium provided spirometric and symptomatic benefits in patients with COPD and was not associated with evidence of electrocardiographic changes in heart rate, rhythm, QT intervals, or conduction.

Positive interaction of the novel beta2-agonist carmoterol and tiotropium bromide in the control of airway changes induced by different challenges in guinea-pigs

This study evaluated the bronchodilating activity of the beta(2)-agonist carmoterol and the muscarinic M(3)-antagonist tiotropium, given intratracheally alone or in combination in anaesthetized artificially ventilated normal and actively sensitized guinea-pigs. Carmoterol (0.3-100pmol) and tiotropium (10-1000pmol) were superfused (0.01ml/min) for 5min before challenges with acetylcholine (20mug/kg i.v.), histamine (10mug/kg i.v.) or ovalbumin (5mg/kg i.v.). Both compounds given alone were markedly active against all the challenges. Tiotropium resulted more effective towards cholinergic challenge and carmoterol was very potent against histamine and ovalbumin-induced reaction, being effective already at 1pmol. In the presence of tiotropium, the bronchodilating activity of carmoterol was significantly augmented. The ED(50) value of carmoterol on the acetylcholine challenge was reduced by about 10 and 28 times (0.1 and 0.3pmol of tiotropium), that on the histamine one by 4.5 and 13 times (1 and 3pmol of tiotropium) and that on the ovalbumin-induced one by 8 and 25 times (10 and 30pmol of tiotropium). A positive interaction was also evident when other parameters were evaluated. The histamine-induced release of thromboxane B(2) was markedly reduced (56%, P<0.001) by combining completely ineffective doses of the two drugs (0.3 and 3pmol for carmoterol and tiotropium, respectively). In ovalbumin-challenged animals the time to death, amounting in control animals to 7.2+/-0.9min, was dose-dependently prolonged up to achieve complete protection from death with combination of 1 and 30pmol of carmoterol and tiotropium, respectively. The favorable interaction between carmoterol and tiotropium can represent a good option in the control of bronchopulmonary diseases marked by an increase of airway resistances.

Does pulmonary rehabilitation give additional benefit over tiotropium therapy in primary care management of chronic obstructive pulmonary disease? Randomized controlled clinical trial in Hong Kong Chinese

OBJECTIVE

To evaluate whether multidisciplinary pulmonary rehabilitation programme (PRP) provides additional benefit over tiotropium therapy in managing chronic obstructive pulmonary disease (COPD) in primary care.

DESIGN

A randomized controlled trial to analyse the difference in outcomes of COPD patients receiving tiotropium plus PRP vs. tiotropium treatment alone.

SETTING

Two primary care teaching clinics affiliated with a university which serves a population of 600,000.

PARTICIPANTS

Fifty primary care COPD patients.

METHODS

Fifty subjects underwent spirometry and their status of COPD was confirmed by using the Vitalograph Gold Standard. They were then assessed by the 6-min walking distance (6MWD), Peak Visual Analogue Scale (Peak VAS) and Chronic Respiratory Disease Questionnaire (CRQ). All subjects were given tiotropium to optimize their treatment. After a 6-week period, half were randomized to the intervention group (i.e. receiving PRP), whereas the rest were randomized to control group which received only medication. Spirometry, 6MWD, Peak VAS and CRQ were performed in both groups at 6 weeks, 12 weeks and 3 months.

OUTCOMES

Spirometry, 6MWD, Peak VAS and CRQ.

RESULTS

Significant improvement (P < 0.05) was seen in 6MWD, symptoms of dyspnoea measured by Peak VAS and CRQ. The improvement was sustained at 3-month follow-up. However, no additional significant improvement was seen in the intervention group when compared with control.

CONCLUSION

Tiotropium therapy has improved health outcomes in COPD patients in primary care settings. A 6 weekly PRP did not give any additional benefits in patients already given tiotropium.

Glycopyrrolate causes prolonged bronchoprotection and bronchodilatation in patients with asthma

INTRODUCTION

Inhaled anticholinergic drugs are effective bronchodilators in the treatment of COPD, and tiotropium bromide has recently been introduced as a once-daily bronchodilator for use as a maintenance treatment. Racemic glycopyrrolate is an anticholinergic drug that has been used orally to control gastric acidity, parenterally as an antisialogogue and to reverse neuromuscular blockade, and has been studied by inhalation for asthma and COPD.

DESIGN AND OBJECTIVE

We investigated the duration of protection against the constrictor effects of inhaled methacholine of a single dose of inhaled nebulized racemic glycopyrrolate (0.5, 1.0, and 2.0 mg) compared with ipratropium bromide (0.5 mg) and placebo in 10 atopic asthmatic volunteers in a double-blind, five-way, crossover study.

RESULTS

Protection against methacholine-induced bronchospasm after administering glycopyrrolate was maintained to 30 h, the last time point measured. Both bronchodilatation and bronchoprotection were significantly longer with glycopyrrolate than after ipratropium bromide, and bronchoprotection was significant at all time points from 2 to 30 h compared to placebo. Dryness of the mouth and nose was described in 18% of patients after the highest dose of glycopyrrolate.

CONCLUSIONS

The prolonged bronchodilator response and the protection against methacholine-induced bronchospasm demonstrated in asthma suggests that inhaled racemic glycopyrrolate would be superior to ipratropium bromide for treatment of stable COPD.

Tiotropium: A Bronchodilator for Chronic Obstructive Pulmonary Disease

OBJECTIVE:

To review the scientific literature evaluating the efficacy and tolerability of tiotropium bromide, a new bronchodilator indicated for treatment of chronic obstructive pulmonary disease (COPD).

DATA SOURCES:

Articles were identified through searches of MEDLINE (1966–January 2005) using the key words tiotropium, BA 679 BR, chronic obstructive pulmonary disease, and anticholinergic agents. Additional citations were identified from bibliographies of publications cited.

STUDY SELECTION AND DATA EXTRACTION:

Experimental and observational studies of tiotropium bromide were selected. Trials of the efficacy of the drug in humans were the focus of the review.

DATA SYNTHESIS:

Tiotropium bromide is an effective bronchodilator for patients with COPD. It produces clinically important improvements in lung function, symptoms of dyspnea, quality of life, and exacerbation rates compared with placebo. In comparative studies, tiotropium does not appear to be more efficacious than salmeterol or ipratropium.

CONCLUSIONS:

Tiotropium is an effective inhaled anticholinergic agent that is recommended among preferred long-acting bronchodilators for the chronic management of moderate to very severe COPD. Although similar to ipratropium in efficacy and tolerability, it has the advantage of once-daily dosing.

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: 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.