A variety of treatment options are available for the treatment of obstructive sleep apnea in addition to positive pressure therapy and surgery. These modes of treatment might be employed in patients who cannot tolerate positive pressure therapy despite aggressive measures to improve compliance. These options include weight reduction, sleep hygiene, positional therapy, and oxygen therapy. Some of the options are still experimental and include pharyngeal muscle and hypoglossal nerve stimulators. A variety of pharmacological agents have also been used. The mechanisms by which these drugs improve sleep-disordered breathing include increasing ventilatory drive and upper airway muscle tone, reducing the amount of rapid eye movement (REM) sleep, and enhancing daytime wakefulness.