Optimal Dosage of Acetazolamide for OSA Treatment

  • End date
    Dec 30, 2022
  • participants needed
  • sponsor
    University Hospital, Antwerp
Updated on 30 May 2021


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.


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.

Condition obstructive sleep apnea syndrome, obstructive sleep apnoea, Obstructive sleep apnea
Treatment Placebo, acetazolamide
Clinical Study IdentifierNCT04726982
SponsorUniversity Hospital, Antwerp
Last Modified on30 May 2021


Yes No Not Sure

Inclusion Criteria

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

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)
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