Objective: To determine if medroxyprogesterone acetate (MPA) can block
the ethanol-induced worsening of obstructive sleep apnea. Design: Ran
domized, double-blind, placebo-controlled, crossover trial with 1 week
treatment periods. Setting: A university-based pulmonary sleep labora
tory. Patients: Fourteen patients with previously diagnosed obstructiv
e sleep apnea not currently receiving any form of therapy for the diso
rder. Eight patients completed the entire protocol. Interventions: Bas
eline overnight polysomnography was performed. On the second study nig
ht, subjects ingested 1 ml/kg body weight 50 percent ethanol prior to
repeat overnight polysomnography. If sleep apnea worsened, subjects th
en received either MPA (20 mg by mouth, three times a day) or placebo
for 7 days then underwent repeat polysomnography with the same ethanol
dose. A washout period followed, then, the other drug was taken, foll
owed again by polysomnography with antecedant ethanol ingestion. Measu
rements and results: Apnea-hypopnea indices (AHI) increased from 9.6+/
-5.3 events/h (baseline) to 20.2+/-16.0 events/h on the ethanol night
(p=0.03). Low oxygen saturation (SaO(2)) fell to 79.2+/-5.1 percent on
the ethanol night compared to baseline, 85.0+/-3.7 percent (p<0.01).
MPA improved AHI, nonrapid eye movement AHI, low SaO(2), mean saturati
on nadir, number of desaturations between 80 and 90 percent, and the m
ean event desaturation when compared with the ethanol alone night. All
these parameters were likewise improved when compared with placebo, a
lthough only the mean saturation nadir showed statistical significance
. These findings were unchanged when also examined for the initial 3 h
ours of study. Conclusions: In obstructive sleep apnea patients whose
disease is made worse by ethanol ingestion, MPA appears to improve oxy
genation during obstructive events but not to improve their number or
length.