Optimal Dosage of Acetazolamide for OSA Treatment

NCT ID: NCT04726982

Last Updated: 2025-09-24

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE4
• Total Enrollment: 91 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2021-04-20
• Study Completion Date: 2024-05-05

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.

Detailed Description

In this double-blind, parallel-group, controlled trial, eligible patients will be randomized into one of the following treatment arms: (1) placebo, (2) 250 mg of acetazolamide, or (3) 500 mg of acetazolamide. After 4 weeks, treatment outcome will be assessed by in-laboratory polysomnography. Additionally, arterial blood gas analysis and lung function tests will be performed before and during treatment.

Conditions

Obstructive Sleep Apnea

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: DOUBLE

Study Groups

Low dose acetazolamide

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

Group Type: EXPERIMENTAL

Acetazolamide

Intervention Type: DRUG

250 mg once daily

High dose acetazolamide

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

Group Type: EXPERIMENTAL

Acetazolamide

Intervention Type: DRUG

500 mg once daily

Placebo

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

Group Type: PLACEBO_COMPARATOR

Placebo

Intervention Type: OTHER

Once daily

Interventions

Acetazolamide

250 mg once daily

Intervention Type: DRUG

Acetazolamide

500 mg once daily

Intervention Type: DRUG

Placebo

Once daily

Intervention Type: OTHER

Other Intervention Names

Diamox; ATC code: S01EC01; Diamox; ATC code: S01EC01

Eligibility Criteria

Inclusion Criteria

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

Exclusion Criteria

• 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

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 79 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University Hospital, Antwerp

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Olivier Vanderveken, MD, PhD

Role: PRINCIPAL_INVESTIGATOR

University Hospital, Antwerp

Locations

Antwerp University Hospital

Edegem, Antwerp, Belgium

Countries

Belgium

Other Identifiers

B3002021000015

Identifier Type: -

Identifier Source: org_study_id