CENTRAL SLEEP-APNEA AFTER INTERRUPTING LONG-TERM ACETAZOLAMIDE THERAPY

One month administration of acetazolamide (ACET) (at sea level) improv es periodic breathing and decreases the number of central apneas (CA) (De Backer et al., 1995 Am. J. Respir. Crit. Care Med. 151, 87-91) in nonhypercapnic central apnea syndrome. It remains unclear whether cess ation of therapy would provoke recurrence of symptoms. In the present study we evaluated the number of CA after 1 and 6 months interruption of ACET therapy. Eight patients with central sleep apnea were included [central apnea index (CAI) > 5 or apnea and hypopnea index (AHI) > 10 and obstructive apnea index (OAI) < 5]. Polysomnography was repeated once after I month treatment (N2): after 1 month off treatment (N3) an d after 6 months off treatment. CAI (25 +/- 10 at N1) decreased during N2 (4 +/- 2) and N3 (5 +/- 3) and remained low after N4 (3 +/- 1). Ho wever an increase in the number of obstructive apneas and central hypo pneas could be observed together with a shift from central apnea to hy popnea after N4. Maybe ACET induces a long lasting resetting of the CO , threshold which is still present after interruption of the therapy. (C) 1998 Elsevier Science B.V. All rights reserved.