Effect of serotonin uptake inhibition on breathing during sleep and daytime symptoms in obstructive sleep apnea

Pharmacologic enhancement of serotonergic transmission by serotonin uptake inhibition has been suggested as one approach to improve upper-airway paten cy and thus nocturnal breathing in patients with obstructive sleep apnea (O SA). To test this hypothesis, we performed a double-blind, randomized, plac ebo-controlled crossover study testing the effect of paroxetine (20 mg od) on polysomnographic and psychopathologic outcomes in 20 male OSA patients ( mean age 52.1 years, mean BMI 28.7 kg/m(2), mean oxygen desaturation index on a previous screening 25.4/hour). The two treatment periods of 6 weeks an d the separating washout period of 4 weeks were completed by 17 patients. P aroxetine reduced the apnea index during NREM sleep (-35%, p=0.003), but no t during REM sleep. No significant effect on hypopnea indices was found. Wi th the exception of a previously described REM-postponing effect (p=0.05), sleep architecture was not significantly influenced by paroxetine. Similarl y, the effect of paroxetine on apnea was not associated with a significant overall alleviation of psychopathologic symptoms as rated on the Comprehens ive Psychopathological Rating Scale or OSA-related daytime complaints asses sed by visual analog scales. We conclude that enhanced serotonergic transmi ssion improves breathing during NREM sleep in OSA. This effect is poorly re lated to effects on sleep architecture or daytime symptoms.