The effects of
therapy with the
tricyclic antidepressant protriptyline were studied in 12 patients with
hypersomnolence and moderately severe
sleep apnea.
After treatment there was no significant change in the duration or frequency of
sleep-disordered breathing (SDB) during non-REM sleep, but there was an alteration in the breathing pattern characterized by a decrease in the amount of
apnea during SDB events.
Apnea, as a percent of disordered breathing time, fell from 60.4 +/- 27.2% to 35.5 +/- 26.7% (p less than 0.01) and was accompanied by a reduction in the peak fall in oxygen saturation from 16.2 +/- 6.2% to 9.2 +/- 4.7% (p less than 0.01). During REM sleep there was no change in the pattern, duration, or frequency of SDB, or reduction in the peak fall in oxygen saturation. However, there was a reduction in the amount of Stage REM sleep, thereby reducing the more severe SDB events (p less than 0.01) and further improving nocturnal oxygenation. In 10 of 12 patients, there was subjective improvement in daytime
hypersomnolence, which was associated with an increase in median sleep onset time from 3.3 +/- 2.2 to 5.1 +/- 2.1 min (p less than 0.01). Although all patients developed mild side effects from the
anticholinergic properties of
protriptyline manifested by a dry mouth, 4 patients noted additional side effects including urinary hesitancy, mild
constipation, and difficulty in maintaining an erection. One patient developed intolerable
constipation that necessitated discontinuation of the
drug. We conclude that
protriptyline reduced daytime
hypersomnolence and altered the pattern of SDB, thus improving gas exchange and oxygenation during sleep. Therefore, in selected patients with moderately severe
obstructive sleep apnea,
therapy with
protriptyline is an alternative to surgical treatment with a
tracheostomy.