Cyclic Vomiting Syndrome in Adults
Cyclic vomiting syndrome (CVS) is a disorder with recurrent episodes of severe nausea and vomiting interspersed with symptom free periods. This syndrome was first described in the English literature in 1882. While CVS has been studied in pediatric populations, its occurrence in adults has been underappreciated. It is now thought that this crippling syndrome can occur in a variety of age groups including adults.
The symptom episodes of CVS tend to follow the same pattern for each individual patient over time. The symptom episodes are characterized by four phases:
- The inter-episodic phase occurs between vomiting episodes when the patient is relatively symptom-free. This phase typically last weeks to months.
- The pre-emesis phase occurs when the patient begins to sense the approach of an episode and has nausea of varying intensity but is still able to take oral medications. This phase lasts minutes to hours.
- The emetic phase is characterized by intense, persistent nausea, vomiting, and other symptoms (abdominal pain, prostration, and lethargy). This phase lasts from hours to days.
- The recovery phase begins with the settling down of nausea and ends when hunger, tolerance of oral intake and vigor returns to normal.
Unfortunately, patients with these symptoms may go for years without correct diagnosis. Initially, patients may be thought to have viral gastroenteritis. However, characteristically these patients often have repeated trips to Emergency Departments seeking relief of the vomiting and the often-accompanying abdominal pain and dehydration. Lack of awareness of this syndrome in adults often delays the diagnosis of CVS. Fortunately, this is being corrected, as more information is becoming available. Recently, criteria for the diagnosis of cyclic vomiting syndrome in adults were published by the Rome III study group on functional GI disorders.
The following three criteria must be fulfilled for the last 3 months with symptom onset at least 6 months before diagnosis:
1. Stereotypical episodes of vomiting regarding onset (acute and duration (less than 1 week)
2. Three or more discrete episodes in the prior year
3. Absence of nausea and vomiting between episodes
Supportive criteria for the diagnosis of CVS includes: History or family history of migraine headaches.
There have been several recent studies of adult patients with cyclic vomiting syndrome. The most uniform feature of the patients in one study was the stereotypical nature of the nausea, vomiting, and abdominal pain with intermittent symptom free periods. The abdominal pain appears to be more pronounced in the adult patients than in pediatric patients. The ages of patients ranged from 18 to 62 years, indicating that many characteristics of CVS are similar irrespective of age of the patient.
The cause of CVS is not known. However, important advances are being made in the clinical understanding of this disorder which may open the way for new treatments.
Treatment of cyclic vomiting syndrome remains largely based on clinical experience. In general, the treatment approach to a patient with CVS should include consideration of lifestyle changes including avoidance of potential triggering factors, drug therapy to prevent subsequent episodes, abortive and/or supportive care treatment during acute episodes, and support of the family.
Medication treatment for patients with CVS is often divided into acute treatment of the vomiting episodes and chronic treatment to try to prevent the episodes. There is a lack of data on the outcomes of patients, particularly adult patients with CVS, to different types of treatment.
A variety of agents are often tried to reduce the nausea and vomiting during the vomiting phase. Antiemetic agents can reduce the severity of episodes and are best used in conjunction with sedatives. This may include the antiemetic agents – prochlorperazine (Compazine) and ondansetron (Zofran). Patients with CVS may respond well to intravenous lorazepam (Ativan), an anti-anxiety medication. Antimigraine triptans can also be used to try to abort episodes.
Tricyclic antidepressants, although not classified as antiemetic agents, can prevent nausea and vomiting since they appear to influence the brain’s regulation of the vomiting process. Tricyclic agents play a favorable role in migraine, depression, anxiety, and the abdominal pain associated with irritable bowel syndrome. They appear to be appropriate therapy to try for the potentially complex disease mechanisms of CVS. Prophylactic antimigraine and anticonvulsive agents are also used to prevent episodes.
It is helpful to have an organized approach to treat these patients in the emergency room where they often need to go for treatment of the acute vomiting phase. A physician letter for the patient to have that describes the syndrome and the appropriate personal treatment is often helpful for patients. Anticipatory support and early treatment intervention are cornerstones to the treatment of CVS.
Cyclic vomiting syndrome can occur in adults as well as children and is an increasingly recognized disorder. Important advances are being made in our clinical understanding of this disorder. New treatments are becoming available. Long-term outcomes and the natural history of cyclic vomiting syndrome in adults will require more studies.