Choline bitartrate (Oxtriphylline) is an orally active methylxanthine-derived choline salt of theophylline. Choline bitartrate exhibits weak antihistaminic and anticholinergic activities and can enhance the effects of histamine and acetylcholine. Choline bitartrate relaxes bronchial smooth muscle, dilates coronary and peripheral blood vessels, increases urine output and electrolyte excretion, stimulates central nervous system motor activity, and induces transient hypotension following a pressor phase. Choline bitartrate modulates sleep architecture by increasing wakefulness time and reducing slow-wave sleep, without altering the frequency or severity of nocturnal hypoxemia, apnea, or hypopnea events. Choline bitartrate is used in studies of bronchospasm, nocturnal asthma, and chronic asthma .