Summary
Acetazolamide has reached the approved stage (maximum clinical phase 4) for at least one indication, so its use in COPD would be drug repurposing rather than first-in-human development. This does not mean it is approved for COPD. ClinicalTrials.gov lists 8 registered trials linking Acetazolamide to COPD: 7 have completed; 1 is terminated, withdrawn, suspended or of unknown status. The most advanced is Phase 4 (NCT01627639). It plans or enrolled 380 participants. Registration activity spans 2011 to 2021. The literature layer holds 8 publications for this pair: 2 Cochrane reviews, 1 meta-analysis and 5 clinical trial publications. Publication years run from 2001 to 2025. Because at least one synthesis-level source exists (systematic review, meta-analysis or Cochrane review), this pair has been assessed beyond single studies, although the synthesis may concern a different indication.
The RepurpOS disease-intelligence file for Chronic Obstructive Pulmonary Disease ranks 505 candidate therapeutics from Open Targets, ChEMBL, DGIdb and PubMed; only a minority carry direct clinical evidence, and this page covers one of those. Spontaneous remission context recorded for the condition: Effectively zero — airflow obstruction is irreversible by definition in COPD; FEV1 decline continues at 30-60 mL/year on standard care.
Evidence table
| Evidence tier | A · Strong |
|---|---|
| Evidence score | 74.0 (trials 30.0, literature 24.0, tier 15, approved bonus 5.0) |
| Registered trials | 8 total: 0 recruiting, 0 active / not yet recruiting, 7 completed, 1 other |
| Linked publications | 8 (5 clinical trial publications, 2 Cochrane reviews, 1 meta-analysis) |
| Agent type | Drug (Small molecule) |
| Development stage (any indication) | Approved |
| Mechanism / class | Not recorded |
| Data sources | Open Targets, ChEMBL |
| Linked via biomarker / target | ADCY5 |
How the evidence score is calculated
- Each registered trial scores by status (recruiting / active / enrolling 3, completed 2.5, not yet recruiting 2, unknown 1, terminated / withdrawn / suspended 0.5) plus a phase bonus (phase 3-4 +2, phase 2 +1, phase 1 +0.5). The trial component is capped at 30.
- Each literature item scores by design (Cochrane review 5, meta-analysis 4, systematic review 3, RCT 3, clinical trial publication 2, curated reference 1.5, other PubMed record 1). The literature component is capped at 30.
- The existing evidence tier adds 15 (A / Strong), 10 (B / Moderate), 5 (C / Preliminary) or 0 (D / Anecdotal).
- Agents approved for any indication (max clinical phase 4) add 5, because an approved agent has an established safety profile that lowers the barrier to repurposing trials.
- The score ranks what has been studied, not what works. It does not read effect sizes or directions of effect.
Registered clinical trials
| NCT ID | Title | Status | Phase | Enrolment |
|---|---|---|---|---|
| NCT03177837 | Effect of Acetazolamide on Exercise Performance in Patients With Respiratory Disease at Altitude 2017 | completed | Phase 4 | 176 |
| NCT03540901 | Effect of Acetazolamide on Lung Water Content by Ultrasound in Patients With Respiratory Disease at Altitude 2018 | completed | Phase 4 | 112 |
| NCT03165890 | Effect of Acetazolamide on Cognition in Patients With Respiratory Disease at Altitude 2017 | completed | Phase 4 | 78 |
| NCT03177850 | Effect of Acetazolamide on Sleep Related Breathing Disturbances in Patients With Respiratory Disease at Altitude 2017 | completed | Phase 4 | 185 |
| NCT03156231 | Effect Of Acetazolamide On Altitude Related Illness In Patients With Respiratory Disease 2017 | completed | Phase 4 | 185 |
| NCT01627639 | Effectiveness of Acetazolamide for Reversal of Metabolic Alkalosis in Mechanically Ventilated Chronic Obstructive Pulmonary Disease Patients 2011 | completed | Phase 4 | 380 |
| NCT01499485 | Treatment of Metabolic Alkalosis With Acetazolamide. Effect on the Length of Mechanical Ventilation. 2011 | completed | Phase 3 | 140 |
| NCT04913389 | Acetazolamide to Prevent Impending Altitude-illness in Patients With COPD 2021 | status unknown | Phase 3 | 100 |
Published literature
- Clinical trial publication Nocturnal cerebral oxygenation in patients with COPD at altitude: data from a randomized clinical trial of acetazolamideSchmuziger YA, Mademilov M, Buergin A et al. · Journal of clinical sleep medicine : JCSM : official publication of the American Academy of Sleep Medicine · 2025 · PMID 41025408
- Meta-analysis High altitudes and partial pressure of arterial oxygen in patients with chronic obstructive pulmonary disease - A systematic review and meta-analysisSevik A, Gaisl T, Forrer A et al. · Pulmonology · 2025 · PMID 39030093
- Cochrane review Acetazolamide for metabolic alkalosis complicating respiratory failure with chronic obstructive pulmonary disease or obesity hypoventilation syndrome: a systematic reviewBemand TJ, Chatoor R, Natale P et al. · Thorax · 2023 · PMID 37217290
- Clinical trial publication Acetazolamide to Prevent Adverse Altitude Effects in COPD and Healthy AdultsFurian M, Mademilov M, Buergin A et al. · NEJM evidence · 2022 · PMID 38296630
- Clinical trial publication Effects of early administration of acetazolamide on the duration of mechanical ventilation in patients with chronic obstructive pulmonary disease or obesity-hypoventilation syndrome with metabolic alkalosis. A randomized trialRialp Cervera G, Raurich Puigdevall JM, Morán Chorro I et al. · Pulmonary pharmacology & therapeutics · 2017 · PMID 28286047
- Clinical trial publication Effect of Acetazolamide vs Placebo on Duration of Invasive Mechanical Ventilation Among Patients With Chronic Obstructive Pulmonary Disease: A Randomized Clinical TrialFaisy C, Meziani F, Planquette B et al. · JAMA · 2016 · PMID 26836730
- Clinical trial publication Acetazolamide improves oxygenation in patients with respiratory failure and metabolic alkalosisGulsvik R, Skjørten I, Undhjem K et al. · The clinical respiratory journal · 2013 · PMID 23578004
- Cochrane review Carbonic anhydrase inhibitors for hypercapnic ventilatory failure in chronic obstructive pulmonary diseaseJones PW, Greenstone M · The Cochrane database of systematic reviews · 2001 · PMID 11279770
Mechanism and notes
No mechanism of action is recorded for this pair in the source databases.
OSMF's existing evidence tier for this pair is A (Strong), derived from the strength of the disease association recorded in Open Targets and ChEMBL, in this case via the biomarker or target ADCY5. The tier describes how well the drug-disease link is documented, not how well the drug works.
Frequently asked questions
Is Acetazolamide approved for COPD?
Acetazolamide has reached the approved stage (maximum clinical phase 4) for at least one indication, so its use in COPD would be drug repurposing rather than first-in-human development. This does not mean it is approved for COPD. Approval status for the specific indication should always be confirmed with the relevant regulator and prescribing information.
Is Acetazolamide in clinical trials for COPD?
ClinicalTrials.gov lists 8 registered trials linking Acetazolamide to COPD: 7 have completed; 1 is terminated, withdrawn, suspended or of unknown status. The most advanced is Phase 4 (NCT01627639). It plans or enrolled 380 participants. Registration activity spans 2011 to 2021.
What does the evidence show for Acetazolamide in COPD?
Acetazolamide has both completed registered trials and synthesis-level publications linked to COPD. That is the strongest profile in this database, but the summaries here do not extract effect sizes, so read the linked reviews for direction and magnitude of benefit. OSMF's existing evidence tier for this pair is A (Strong), derived from the strength of the disease association recorded in Open Targets and ChEMBL, in this case via the biomarker or target ADCY5. The tier describes how well the drug-disease link is documented, not how well the drug works.
Cite this page
Data: ClinicalTrials.gov, PubMed, Open Targets, ChEMBL, DGIdb and the OSMF therapeutic agent database. Last updated 2026-07-05. Page built 2026-10-07.