Impact of acetazolamide and CPAP on cortical activity in obstructive sleep apnea patients.
OBJECTIVE
1) To investigate the impact of acetazolamide, a drug commonly prescribed for altitude sickness, on cortical oscillations in patients with obstructive sleep apnea syndrome (OSAS). 2) To examine alterations in the sleep EEG after short-term discontinuation of continuous positive airway pressure (CPAP) therapy.


METHODS
Data from two double-blind, placebo-controlled randomized cross-over design studies were analyzed.


METHODS
Polysomnographic recordings in sleep laboratory at 490 m and at moderate altitudes in the Swiss Alps: 1630 or 1860 m and 2590 m.


METHODS
Study 1: 39 OSAS patients. Study 2: 41 OSAS patients.


METHODS
Study 1: OSAS patients withdrawn from treatment with CPAP. Study 2: OSAS patients treated with autoCPAP. Treatment with acetazolamide (500-750 mg) or placebo at moderate altitudes.


RESULTS
An evening dose of 500 mg acetazolamide reduced slow-wave activity (SWA; approximately 10%) and increased spindle activity (approximately 10%) during non-REM sleep. In addition, alpha activity during wake after lights out was increased. An evening dose of 250 mg did not affect these cortical oscillations. Discontinuation of CPAP therapy revealed a reduction in SWA (5-10%) and increase in beta activity (approximately 25%).


CONCLUSIONS
The higher evening dose of 500 mg acetazolamide showed the "spectral fingerprint" of Benzodiazepines, while 250 mg acetazolamide had no impact on cortical oscillations. However, both doses had beneficial effects on oxygen saturation and sleep quality.
Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
Katrin
K
Stadelmann
Pulmonary Division, University Hospital Zurich, Zurich, Switzerland.
Tsogyal D
TD
Latshang
Pulmonary Division, University Hospital Zurich, Zurich, Switzerland.
Yvonne
Y
Nussbaumer-Ochsner
Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland; University Hospital of Child and Adolescent Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland.
Leila
L
Tarokh
Pulmonary Division, University Hospital Zurich, Zurich, Switzerland.
Silvia
S
Ulrich
Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland; Pulmonary Division, University Hospital Zurich, Zurich, Switzerland.
Malcolm
M
Kohler
Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland; Pulmonary Division, University Hospital Zurich, Zurich, Switzerland.
Konrad E
KE
Bloch
Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
Peter
P
Achermann
D000086:Acetazolamide / Q000494:pharmacology / Q000627:therapeutic use*; D000368:Aged; D000532:Altitude Sickness / Q000188:drug therapy / Q000503:physiopathology; D002257:Carbonic Anhydrase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D002540:Cerebral Cortex / Q000187:drug effects / Q000503:physiopathology*; D045422:Continuous Positive Airway Pressure; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000188:drug therapy / Q000503:physiopathology* / Q000628:therapy
D002257:Carbonic Anhydrase Inhibitors; D000086:Acetazolamide