Optimal Dosage of Acetazolamide for OSA Treatment

NCT04726982 | Completed Phase 4

• 1 other identifier: B3002021000015
• Study Type: interventional
• Target: 91
• Locations: 1 country
• Sites: 1

Brief Summary

Acetazolamide, a carbonic anhydrase inhibitor, has received some attention as potential treatment for obstructive sleep apnea (OSA). It produces a metabolic acidosis by excreting bicarbonate, thereby stimulating baseline ventilation. Evidence suggests that acetazolamide primarily improves ventilatory control instability (expressed as loop gain), which is an important contributor to the pathophysiology of OSA. Few studies have assessed the efficacy of acetazolamide in patients with OSA. Since most of them had a small sample size and used different therapeutic dosages, clinical applications are currently limited. Therefore, this study aims to compare the effect of two acetazolamide dosages on the severity and pathophysiology of OSA.

Conditions

Obstructive Sleep Apnea

Keywords

Carbonic anhydrase inhibitor; Treatment; Pharmacotherapy; Sleep apnea; Loop gain; Respiration; Ventilatory control instability; Acidosis

Outcome Measures

Primary Outcomes (1)

• Apnea-hypopnea index (AHI)

  Change in AHI (events/hour) from baseline to follow-up. The AHI is a measure of sleep apnea severity that encompasses the frequency of apneas (cessations in breathing) and hypopneas (reductions in airflow).

  4 weeks

Secondary Outcomes (9)

• Pathophysiological traits

  4 weeks

• Percent responders

  4 weeks

• Nocturnal oxygen saturation

  4 weeks

• Oxygen desaturation index (ODI)

  4 weeks

• Arterial blood gas measurements

  4 weeks

Other Outcomes (1)

• Incidence of adverse events

  6 weeks

Study Arms (3)

Low dose acetazolamide

EXPERIMENTAL

Unembellished white tablets. The drug should be taken one hour before bedtime. Total treatment duration will be 6 weeks.

Drug: Acetazolamide

High dose acetazolamide

EXPERIMENTAL

Unembellished white tablets. The drug should be taken one hour before bedtime. Total treatment duration will be 6 weeks.

Drug: Acetazolamide

Placebo

PLACEBO COMPARATOR

Matching placebo tablets. The drug should be taken one hour before bedtime. Total treatment duration will be 6 weeks.

Other: Placebo

Interventions

Acetazolamide DRUG

250 mg once daily

Also known as: Diamox, ATC code: S01EC01

Low dose acetazolamide

Placebo OTHER

Once daily

Placebo

Eligibility Criteria

• Age: 18 Years - 79 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• AHI between 15 and 65 events/hour
• BMI \< 35 kg/m²

You may not qualify if:

• Craniofacial anomalies
• Central sleep apnea (defined as central AHI \> 25% of total AHI)
• Contra-indications related to acetazolamide treatment
• Hypersensitivity to sulphonamides or acetazolamide
• Renal impairment, electrolyte imbalances, and/or adrenocortical insufficiency
• Clinically significant metabolic, hepatic, and/or hematological disease
• Chronic obstructive pulmonary disease
• Closed-angle glaucoma
• Conditions likely to affect OSA physiology: neuromuscular disease or other major neurological disorders, heart failure, or any other unstable major medical condition.
• Intake of drugs that substantially stimulate or depress respiration, including benzodiazepines, opioids, theophylline, and pseudoephedrine
• Inadequately treated sleep disorders other than OSA that would confound functional sleep assessment
• Inability of the patient to understand and/or comply to the study procedures
• Active psychiatric disease (psychotic illness, major depression, anxiety attacks, alcohol or drug abuse)
• Pregnancy

Sponsors & Collaborators

• University Hospital, Antwerp: lead

Study Sites (1)

Antwerp University Hospital

Edegem, Antwerp, 2650, Belgium

Location

MeSH Terms

Conditions

Sleep Apnea, Obstructive; Sleep Apnea Syndromes; Respiratory Aspiration; Acidosis

Interventions

Acetazolamide

Condition Hierarchy (Ancestors)

Apnea; Respiration Disorders; Respiratory Tract Diseases; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Wake Disorders; Nervous System Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Acid-Base Imbalance; Metabolic Diseases; Nutritional and Metabolic Diseases

Intervention Hierarchy (Ancestors)

Thiadiazoles; Thiazoles; Sulfur Compounds; Organic Chemicals; Azoles; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds

Study Officials

• Olivier Vanderveken, MD, PhD

  University Hospital, Antwerp

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, CARE PROVIDER
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 26, 2021
• First Posted: January 27, 2021
• Study Start: April 20, 2021
• Primary Completion: March 19, 2024
• Study Completion: May 5, 2024
• Last Updated: September 24, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

BE (1)