The role of protriptyline in obstructive sleep apnea

Protriptyline, a non-sedating tricyclic agent, was evaluated in a double blind drug-placebo crossover trial in five obese patients with obstructive sleep apnea. Four of the five patients had improvement in somnolence. Protriptyline improved oxygenation. This seemed related primarily to a reduction (from 23% to 11%) in REM, with fewer of the more severe REM apneas. Arousal frequency remained quite high; thus the reason for the reduction in somnolence remains unclear. In three patients, at six months the improvement in clinical status and oxygenation persisted. We have now attempted long term treatment in nine patients. In five, anticholinergic side-effects necessitated stopping therapy. Four patients continue to do well. A trial of protriptyline is thus indicated in treatment of mild to moderate obstructive apnea or when the patient refuses more invasive treatment.