Treatment of cyclic vomiting syndrome.

Cyclic vomiting syndrome (CVS) is a relatively rare but highly incapacitating disorder. It is seen both in children and adults, although classically it has been perceived as a pediatric gastrointestinal disorder. Recent studies have demonstrated that this disorder indeed can be seen in adults and is highly disabling. Although classically associated with migraine headaches in the pediatric form, this relationship is less well established in adults. This has major implications for management in that traditionally, one of the major avenues for treatment of pediatric CVS has been antimigraine drugs. An additional factor that obscures a review of CVS treatment is the fact that because of its relative rarity, no randomized controlled trials (RCTs) have been performed. In the absence of RCTs, it is difficult to make definitive recommendations regarding treatment. The literature to date consists of case reports and open-ended case series. However, despite these limitations, it is the goal of this article to present in a comprehensive manner the options available for the treatment of CVS. Recognizing the limitations in the literature, it is clear that a number of treatment strategies that can often prove effective for the treatment of these complicated and often-challenging patients are available. Treatment is divided between acute intervention, when a patient is actively and severely vomiting, and prophylactic treatment for patients in their "interictal" phase, the goal of which is reducing frequency and intensity of subsequent episodes. Finally, we are beginning to identify possible mechanisms of the cause of CVS. Once these are better understood, this will provide the basis for further improvement in treatment.