Effectiveness and safety of inhalers containing the drug aclidinium bromide for managing patients with stable COPD

Review question

We reviewed the evidence on the effectiveness and safety of aclidinium inhalers used by people with chronic obstructive pulmonary disease (COPD).


COPD, also known as 'smoker's lung disease', includes conditions called emphysema and chronic bronchitis where there is airway narrowing that cannot be fully corrected. It is a progressive disease. COPD patients usually have breathing problems and a cough that produces a lot of phlegm. It is diagnosed by international guidelines set by the Global Initiative for Obstructive Lung Disease (GOLD). Symptoms may worsen during flare-ups. The main aims of treating COPD patients are to relieve symptoms, reduce flare-ups and improve quality of life. Aclidinium is a new inhaled drug that widens the airways (a bronchodilator). It is delivered by an inhaler called Genuair or Pressair. We wanted to discover whether aclidinium was better or worse than using other inhalers or a dummy inhaler.

Study characteristics

The evidence was current to 7 April 2014. We included 12 studies involving 9547 COPD patients over a period of four to 52 weeks. These studies were sponsored by drug companies and were well designed. Both patients and the people doing the research did not know which treatment the patients were getting; although in one study one treatment was known to both parties. More men than women took part, and they were mostly Caucasians. They were in their 60s and had smoked a lot in their lives. These people had moderate to severe symptoms when they started treatment.

Key results

Aclidinium did not reduce the number of people with flare-ups that need additional drugs. There was little or no difference in deaths or serious side effects between aclidinium and a dummy inhaler. Aclidinium inhalers improved quality of life more than the dummy inhalers.

People who took aclidinium had fewer hospital admissions due to serious flare-ups. Based on our results, among 1000 COPD patients using a dummy inhaler over four weeks to one year 37 would have severe flare-ups needing hospital admission. Only 17 to 33 patients out of 1000 would require hospital admission if they were using aclidinium inhalers. We also set out to compare this new medication with tiotropium, which is already used to treat COPD. There were only two studies for this comparison thus we could not be sure how aclidinium compared to tiotropium. We also could not compare aclidinium with another well known inhaler that contains the drug formoterol because of unreliable data.

Quality of the evidence

For the comparison of aclidinium inhalers and dummy inhalers, we are confident that there are benefits in terms of the number of hospitalisations and patients' quality of life; we are less certain about the numbers of flare-ups needing additional drugs and serious side effects. We do not have enough information to assess any effect on the number of deaths. We did not have enough information to reliably compare aclidinium with tiotropium or formoterol.

Authors' conclusions: 

Aclidinium is associated with improved quality of life and reduced hospitalisations due to severe exacerbations in patients with moderate to severe stable COPD compared to placebo. Overall, aclidinium did not significantly reduce mortality, serious adverse events or exacerbations requiring oral steroids or antibiotics, or both.

Currently, the available data are insufficient and of very low quality in comparisons of the efficacy of aclidinium versus tiotropium. The efficacy of aclidinium versus LABAs cannot be assessed due to inaccurate data. Thus additional trials are recommended to assess the efficacy and safety of aclidinium compared to other LAMAs or LABAs.

Read the full abstract...

Bronchodilators are the mainstay for symptom relief in the management of stable chronic obstructive pulmonary disease (COPD). Aclidinium bromide is a new long-acting muscarinic antagonist (LAMA) that differs from tiotropium by its higher selectivity for M3 muscarinic receptors with a faster onset of action. However, the duration of action of aclidinium is shorter than for tiotropium. It has been approved as maintenance therapy for stable, moderate to severe COPD, but its efficacy and safety in the management of COPD is uncertain compared to other bronchodilators.


To assess the efficacy and safety of aclidinium bromide in stable COPD.

Search strategy: 

We identified randomised controlled trials (RCT) from the Cochrane Airways Group Specialised Register of trials (CAGR), as well as www.clinicaltrials.gov, World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), US Food and Drug Administration (FDA) website and Almirall Clinical Trials Registry and Results. We contacted Forest Laboratories for any unpublished trials and checked the reference lists of identified articles for additional information. The last search was performed on 7 April 2014 for CAGR and 11 April 2014 for other sources.

Selection criteria: 

Parallel-group RCTs of aclidinium bromide compared with placebo, long-acting beta2-agonists (LABA) or LAMA in adults with stable COPD.

Data collection and analysis: 

Two review authors independently selected studies, assessed the risk of bias, and extracted data. We sought missing data from the trial authors as well as manufacturers of aclidinium. We used odds ratios (OR) for dichotomous data and mean difference (MD) for continuous data, and reported both with their 95% confidence intervals (CI). We used standard methodological procedures expected by The Cochrane Collaboration. We applied the GRADE approach to summarise results and to assess the overall quality of evidence.

Main results: 

This review included 12 multicentre RCTs randomly assigning 9547 participants with stable COPD. All the studies were industry-sponsored and had similar inclusion criteria with relatively good methodological quality. All but one study included in the meta-analysis were double-blind and scored low risk of bias. The study duration ranged from four weeks to 52 weeks. Participants were more often males, mainly Caucasians, mean age ranging from 61.7 to 65.6 years, and with a smoking history of 10 or more pack years. They had moderate to severe symptoms at randomisation; the mean post-bronchodilator forced expiratory volume in one second (FEV1) was between 46% and 57.6% of the predicted normal value, and the mean St George's Respiratory Questionnaire score (SGRQ) ranged from 45.1 to 50.4 when reported.

There was no difference between aclidinium and placebo in all-cause mortality (low quality) and number of patients with exacerbations requiring a short course of oral steroids or antibiotics, or both (moderate quality). Aclidinium improved quality of life by lowering the SGRQ total score with a mean difference of -2.34 (95% CI -3.18 to -1.51; I2 = 48%, 7 trials, 4442 participants) when compared to placebo. More patients on aclidinium achieved a clinically meaningful improvement of at least four units decrease in SGRQ total score (OR 1.49; 95% CI 1.31 to 1.70; I2 = 34%; number needed to treat (NNT) = 10, 95% CI 8 to 15, high quality evidence) over 12 to 52 weeks than on placebo. Aclidinium also resulted in a significantly greater improvement in pre-dose FEV1 than placebo with a mean difference of 0.09 L (95% CI 0.08 to 0.10; I2 = 39%, 9 trials, 4963 participants). No trials assessed functional capacity. Aclidinium reduced the number of patients with exacerbations requiring hospitalisation by 4 to 20 fewer per 1000 over 4 to 52 weeks (OR 0.64; 95% CI 0.46 to 0.88; I2 = 0%, 10 trials, 5624 people; NNT = 77, 95% CI 51 to 233, high quality evidence) compared to placebo. There was no difference in non-fatal serious adverse events (moderate quality evidence) between aclidinium and placebo.

Compared to tiotropium, aclidinium did not demonstrate significant differences for exacerbations requiring oral steroids or antibiotics, or both, exacerbation-related hospitalisations and non-fatal serious adverse events (very low quality evidence). Inadequate data prevented the comparison of aclidinium to formoterol or other LABAs.