Aclidinium Bromide
Indications
| Indication | Approved Population | Therapy Type | Status |
|---|---|---|---|
| Maintenance treatment of bronchospasm associated with COPD, including chronic bronchitis and emphysema | Adults | Maintenance monotherapy or in combination with other COPD therapies | FDA Approved |
Aclidinium bromide is a long-acting muscarinic antagonist (LAMA) approved in the United States in July 2012 for maintenance bronchodilation in patients with COPD. It is classified alongside tiotropium, umeclidinium, and glycopyrronium as a long-acting anticholinergic bronchodilator, but is distinguished by its rapid onset of action (within minutes), twice-daily dosing schedule, and rapid systemic hydrolysis which contributes to a favourable systemic side-effect profile. The GOLD guidelines recommend LAMAs as first-line maintenance therapy for patients with persistent symptoms or exacerbation risk (GOLD Groups B–E). Aclidinium is delivered via the Pressair (known as Genuair in Europe), a breath-actuated dry powder inhaler that provides dose confirmation via an audible click and colour change.
Asthma-COPD overlap: Evidence quality — Low. Some clinicians use aclidinium as add-on bronchodilator therapy in patients with features of both asthma and COPD, though formal trial data in this population are limited. GINA/GOLD recommendations suggest LAMA add-on to ICS-LABA in overlap phenotypes.
Dosing
| Clinical Scenario | Starting Dose | Maintenance Dose | Maximum Dose | Notes |
|---|---|---|---|---|
| COPD maintenance — stable disease, symptom control | 400 mcg inhaled BID | 400 mcg inhaled BID | 400 mcg BID (no benefit from higher doses) | Dose morning and evening ~12 h apart No titration required; fixed-dose regimen |
| COPD maintenance — patient with cardiovascular comorbidity | 400 mcg inhaled BID | 400 mcg inhaled BID | 400 mcg BID | ASCENT-COPD trial confirmed cardiovascular safety in high-risk patients No dose adjustment needed |
| COPD maintenance — renal impairment (any severity) | 400 mcg inhaled BID | 400 mcg inhaled BID | 400 mcg BID | Renal clearance plays a minor role (<1% excreted unchanged) PK study showed no clinically significant effect of renal impairment |
| COPD maintenance — elderly (≥65 years) | 400 mcg inhaled BID | 400 mcg inhaled BID | 400 mcg BID | No overall differences in safety/efficacy observed in patients ≥70 years No age-based dose adjustment warranted |
Aclidinium has one of the simplest dosing regimens among COPD medications: a single inhaled dose strength (400 mcg) given twice daily with no titration, no renal adjustment, and no hepatic adjustment. The Pressair inhaler is breath-actuated, eliminating the need for hand-breath coordination required with metered-dose inhalers. Patients should be instructed that the device confirms successful inhalation with an audible click and a colour change in the control window from green to red. The inhaler should be discarded 45 days after the sealed pouch is first opened, when the dose counter reads “0”, or when the device locks out — whichever comes first.
Pharmacology
Mechanism of Action
Aclidinium bromide is a synthetic quaternary ammonium compound that competitively and reversibly inhibits muscarinic acetylcholine receptors. It demonstrates similar binding affinity across all five muscarinic receptor subtypes (M1–M5), but displays kinetic selectivity for M3 over M2 receptors. The dissociation half-life from M3 receptors is approximately 29.2 hours, roughly six times longer than its dissociation half-life from M2 receptors. This kinetic selectivity is clinically significant: M3 blockade on airway smooth muscle produces sustained bronchodilation, while the shorter M2 occupancy reduces the risk of cardiac effects such as tachycardia. Bronchodilation occurs through inhibition of M3-mediated bronchoconstriction and reduction of mucus hypersecretion in submucosal glands. A unique feature of aclidinium is its rapid hydrolysis by plasma esterases (primarily butyrylcholinesterase) into two pharmacologically inactive metabolites, resulting in very low and transient systemic exposure and a reduced burden of class-related anticholinergic adverse effects.
ADME Profile
| Parameter | Value | Clinical Implication |
|---|---|---|
| Absorption | Tmax 5–15 min post-inhalation; ~30% lung deposition; systemic bioavailability <5% | Very rapid onset of bronchodilation; low systemic absorption limits off-target effects |
| Distribution | Vd ~300 L (IV); protein binding: acid metabolite 87%, alcohol metabolite 15% | Large Vd reflects extensive tissue distribution; parent compound too rapidly hydrolysed for meaningful plasma protein binding |
| Metabolism | Rapid hydrolysis by plasma BuChE and non-enzymatic ester cleavage to inactive alcohol (LAS34823) and acid (LAS34850) metabolites; CYP450 plays a negligible role | No CYP-mediated drug interactions expected; rapid systemic inactivation is the key differentiator from longer-acting LAMAs like tiotropium |
| Elimination | ~1% excreted unchanged in urine; metabolites: 54–65% urine, 20–33% faeces; effective t½ 5–8 h | Renal clearance of parent drug is negligible; no dose adjustment needed for any degree of renal impairment |
Side Effects
No adverse reactions reached an incidence of ≥10% in pivotal placebo-controlled trials. The highest-frequency adverse reaction was headache at 6.6%. This favourable profile is attributed to the rapid systemic hydrolysis of aclidinium, which limits circulating parent drug concentrations.
| Adverse Effect | Incidence (Aclidinium) | Clinical Note |
|---|---|---|
| Headache | 6.6% (vs 5.0% placebo) | Most common adverse reaction; generally mild and transient |
| Nasopharyngitis | 5.5% (vs 3.9% placebo) | May reflect upper airway drying effects of anticholinergic; typically self-limiting |
| Cough | 3.0% (vs 2.2% placebo) | Related to DPI powder inhalation; distinguish from bronchospasm |
| Diarrhoea | 2.7% (vs 1.4% placebo) | Typically mild; not a class effect of antimuscarinics |
| Sinusitis | 1.7% (vs 0.8% placebo) | May relate to mucosal drying; monitor for secondary infection |
| Rhinitis | 1.6% (vs 1.2% placebo) | Mild nasal irritation; generally does not require treatment change |
| Toothache | 1.1% (vs 0.8% placebo) | Possibly related to dry mouth effects on oral health |
| Fall | 1.1% (vs 0.5% placebo) | Consider anticholinergic burden in elderly; may relate to dizziness |
| Vomiting | 1.1% (vs 0.5% placebo) | Infrequent; monitor for dehydration in elderly patients |
| Adverse Effect | Estimated Frequency | Typical Onset | Required Action |
|---|---|---|---|
| Paradoxical bronchospasm | Very rare | Within minutes of inhalation | Discontinue aclidinium immediately; treat with short-acting bronchodilator; consider alternative maintenance therapy |
| Anaphylaxis / angioedema | Very rare (postmarketing) | Minutes to hours | Standard anaphylaxis management; permanent discontinuation; consider atropine cross-sensitivity |
| Acute angle-closure glaucoma | Very rare | Hours to days | Immediate ophthalmology referral; discontinue aclidinium; topical miotics |
| Urinary retention | Rare (postmarketing) | Days to weeks | Discontinue if significant retention; catheterisation if needed; particular risk with prostatic hyperplasia |
| Cardiac failure / cardiorespiratory arrest | <1% (clinical trials) | Variable | Emergency care; note ASCENT-COPD showed no increased MACE risk vs placebo (HR 0.89) |
The FDA-required ASCENT-COPD trial (N=3,630; up to 3 years) specifically enrolled patients with COPD and elevated cardiovascular risk. Aclidinium met the primary noninferiority endpoint for MACE (HR 0.89; 1-sided 97.5% CI upper bound 1.23, below the 1.8 noninferiority margin). This provides robust reassurance regarding cardiovascular safety, an important consideration given historical concerns about the LAMA class.
Drug Interactions
Aclidinium has an exceptionally low drug interaction potential. It is rapidly hydrolysed by plasma esterases rather than metabolised by hepatic CYP450 enzymes, and in vitro studies confirm that neither aclidinium nor its metabolites inhibit or induce major CYP isoforms. No formal drug interaction studies were required by the FDA. In clinical trials, co-administration with short-acting beta-2 agonists, methylxanthines, and oral or inhaled corticosteroids produced no increase in adverse reactions.
Monitoring
-
Lung Function
Baseline, then every 3–12 months
Routine Assess trough FEV1 to confirm bronchodilator response. In pivotal trials, aclidinium improved morning trough FEV1 by ~100–130 mL vs placebo at 12–24 weeks. Reassess if benefit wanes. -
Inhaler Technique
Each visit
Routine Verify the patient hears the click and sees the colour change from green to red confirming successful inhalation. Minimum inspiratory flow of 35 L/min is required. Re-demonstrate technique at each encounter. -
Symptom Scores
Every 3–6 months
Routine Use validated tools (CAT, mMRC) to track symptom burden and treatment response. ASCENT-COPD showed sustained improvement in CAT scores with aclidinium. -
Urinary Symptoms
If symptoms develop
Trigger-based Inquire about difficulty urinating, particularly in male patients with known prostatic hyperplasia. Discontinue if clinically significant retention occurs. -
Ocular Symptoms
If symptoms develop
Trigger-based Counsel patients to report eye pain, blurred vision, visual halos, or red eyes immediately. Risk of acute narrow-angle glaucoma is present with all inhaled anticholinergics. -
Exacerbation Frequency
Ongoing
Routine Track moderate and severe COPD exacerbations. ASCENT-COPD demonstrated exacerbation reduction with aclidinium added to background therapy. Escalate treatment (add LABA, ICS) per GOLD if exacerbations persist.
Contraindications & Cautions
Absolute Contraindications
- Severe hypersensitivity to milk proteins — the Pressair formulation contains lactose monohydrate which may contain trace milk proteins
- Hypersensitivity to aclidinium bromide or any excipient
Relative Contraindications (Specialist Input Recommended)
- Narrow-angle glaucoma: Use with caution; anticholinergics may precipitate acute angle-closure. Patients with a history of narrow-angle glaucoma should be assessed by ophthalmology before starting
- Symptomatic prostatic hyperplasia or bladder-neck obstruction: Risk of worsening urinary retention; close monitoring required
Use with Caution
- History of hypersensitivity to atropine: Given structural similarities, cross-reactivity is possible; monitor closely
- Severe COPD with very low inspiratory flow: The Pressair device requires a minimum inspiratory flow of ~35 L/min; patients unable to generate this flow may not receive an adequate dose
Aclidinium bromide is a maintenance therapy and must not be used for the relief of acute episodes of bronchospasm. Patients should always have a short-acting bronchodilator (e.g., salbutamol) available for rescue use. If paradoxical bronchospasm occurs after inhalation, treatment should be stopped immediately and alternative therapies considered.
Patient Counselling
Purpose of Therapy
Aclidinium is a controller medication that keeps the airways open by blocking a chemical messenger (acetylcholine) that causes the airway muscles to tighten. It works locally in the lungs and is broken down very quickly in the bloodstream, which helps limit side effects elsewhere in the body. It is used every day, morning and evening, to prevent breathing difficulties — it does not relieve sudden shortness of breath.
How to Take
Remove the inhaler from the sealed pouch only when ready to start using it. Before each dose, press and release the green button fully, then exhale gently away from the device and inhale forcefully and deeply through the mouthpiece. You should hear a “click” and see the control window change from green to red — this confirms a successful dose. If the window does not change colour, repeat the inhalation. Use approximately 12 hours apart (e.g., morning and evening). Do not clean the inside of the device; the outside can be wiped with a dry tissue. Discard the inhaler 45 days after opening the pouch, or when the dose counter shows “0”.
Sources
- Tudorza Pressair (aclidinium bromide inhalation powder) prescribing information. Covis Pharma GmbH. Revised 03/2019. FDA Label Primary regulatory source for all dosing, adverse reaction data (Table 1), contraindications, warnings, and drug interaction information.
- FDA Clinical Pharmacology Review: NDA 202450. Center for Drug Evaluation and Research. 2012. FDA Review Source for detailed pharmacokinetic parameters including effective half-life (5–8 h), renal impairment PK data, and accumulation indices.
- Wise RA, Chapman KR, Scirica BM, et al. Effect of aclidinium bromide on major cardiovascular events and exacerbations in high-risk patients with COPD: the ASCENT-COPD randomized clinical trial. JAMA. 2019;321(17):1693–1701. DOI Phase IV cardiovascular safety trial (N=3,630; up to 3 years). Established MACE noninferiority (HR 0.89) and exacerbation reduction vs placebo in high-CV-risk patients.
- Kerwin EM, D’Urzo AD, Gelb AF, et al. Efficacy and safety of a 12-week treatment with twice-daily aclidinium bromide in COPD patients (ACCORD COPD I). COPD. 2012;9(2):90–101. DOI Pivotal Phase III trial demonstrating FEV1 improvement and safety of aclidinium 400 mcg BID over 12 weeks.
- Jones PW, Singh D, Bateman ED, et al. Efficacy and safety of twice-daily aclidinium bromide in COPD patients: the ATTAIN study. Eur Respir J. 2012;40(4):830–836. DOI 24-week pivotal trial confirming sustained bronchodilation and health status improvement (SGRQ) with aclidinium 400 mcg BID.
- Rennard SI, Scanlon PD, Ferguson GT, et al. ACCORD COPD II: a randomized clinical trial to evaluate the 12-week efficacy and safety of twice-daily aclidinium bromide in COPD patients. Clin Drug Investig. 2013;33(12):893–904. DOI Confirmatory Phase III trial supporting the ACCORD I findings with consistent FEV1 and safety results.
- Global Initiative for Chronic Obstructive Lung Disease (GOLD). Global Strategy for the Diagnosis, Management, and Prevention of COPD. 2025 Report. GOLD Current international guideline recommending LAMAs as first-line maintenance therapy for symptomatic COPD (Groups B–E).
- Gavalda A, Miralpeix M, Ramos I, et al. Characterization of aclidinium bromide, a novel inhaled muscarinic antagonist, with long duration of action and a favorable pharmacological profile. J Pharmacol Exp Ther. 2009;331(2):740–751. DOI Foundational pharmacology study establishing M3 kinetic selectivity (dissociation t½ 29.2 h vs 4.7 h at M2), rapid plasma hydrolysis, and in vivo bronchodilatory profile.
- Alberti JJ, Sentellas S, Salva M. In vitro liver metabolism of aclidinium bromide in preclinical animal species and humans: identification of the human enzymes involved in its oxidative metabolism. Biochem Pharmacol. 2011;81(6):761–776. DOI Identified butyrylcholinesterase as the primary enzyme responsible for aclidinium hydrolysis; confirmed negligible CYP involvement.
- Schmid K, Pascual S, Garcia Gil E, Ortiz S, Jansat JM. Pharmacokinetics and safety of aclidinium bromide, a muscarinic antagonist, in adults with normal or impaired renal function. Clin Ther. 2010;32(10):1798–1812. DOI Phase I renal impairment study confirming that aclidinium PK is unaffected by renal function; basis for no dose adjustment recommendation.
- Ortiz S, Flach S, Ho J, et al. Mass balance and metabolism of aclidinium bromide following intravenous administration of [14C]-aclidinium bromide in healthy subjects. Biopharm Drug Dispos. 2012;33(1):39–45. DOI Radiolabelled mass balance study quantifying urinary (54–65%) and faecal (20–33%) excretion of metabolites, with only 1% as unchanged aclidinium.
- Lasseter K, Dilzer S, Jansat JM, et al. Safety and pharmacokinetics of multiple doses of aclidinium bromide administered twice daily in healthy volunteers. Pulm Pharmacol Ther. 2012;25(2):193–199. DOI Multiple-dose PK study establishing effective half-life (4.6–7.0 h at 400 mcg), steady state within 7 days, and time-independent pharmacokinetics.