Central sleep apnea after interrupting longterm acetazolamide therapy

Area of Science:

• Sleep Medicine
• Respiratory Physiology

Background:

• Acetazolamide (ACET) improves periodic breathing and central apneas (CA) in nonhypercapnic central sleep apnea syndrome.
• The long-term effects of discontinuing ACET therapy on CA recurrence are not well understood.

Purpose of the Study:

• To evaluate the number of central apneas (CA) after 1 and 6 months of interrupting acetazolamide (ACET) therapy.
• To investigate potential recurrence of central sleep apnea (CSA) symptoms after ACET cessation.

Main Methods:

• Eight patients with central sleep apnea (CSA) (CAI > 5 or AHI > 10 and OAI < 5) were studied.
• Polysomnography was performed after 1 month of ACET treatment, and then 1 and 6 months after treatment cessation.
• Central apnea index (CAI), obstructive apnea index (OAI), and apnea-hypopnea index (AHI) were assessed.

Main Results:

• Central apnea index (CAI) significantly decreased during ACET treatment and remained low at 1 and 6 months after cessation (25 +/- 10 at baseline to 4 +/- 2 and 5 +/- 3, respectively).
• A notable increase in obstructive apneas and central hypopneas was observed after treatment cessation.
• A shift from central apneas to hypopneas occurred after ACET interruption.

Conclusions:

• Acetazolamide (ACET) therapy may induce a long-lasting resetting of the CO2 threshold in patients with central sleep apnea (CSA).
• The therapeutic benefits of ACET on central apneas appear to persist for at least six months after discontinuation.
• Further research is warranted to understand the mechanisms behind the sustained effect and the observed shift towards hypopneas.