From the Guidelines
For patients with cyclical vomiting syndrome who do not respond to ondansetron, the next step typically involves trying other antiemetic medications or sedating agents, such as sumatriptan, promethazine, or prochlorperazine, as part of an "abortive cocktail" of medications 1. When considering the next step for these patients, it's essential to prioritize a combination approach that targets both acute episodes and prevention.
- The goal of abortive therapy is to completely avoid the emetic phase or drastically reduce its severity, and using a combination of medications, such as sumatriptan and an antiemetic agent, can be effective 1.
- Sedating agents, such as promethazine, diphenhydramine, or benzodiazepines, like alprazolam, may also be useful in inducing sedation and aborting CVS attacks 1.
- If patients cannot abort an episode at home, presentation to an emergency department for intravenous fluids and abortive therapy is reasonable 1.
- In the recovery phase, the priority is to consume electrolyte-rich fluids, such as sports drinks, to help manage symptoms and support recovery 1.
- A symptom diary can help identify triggers, and counseling on lifestyle modifications, such as regular sleep patterns and stress management techniques, can also be beneficial in managing CVS 1.
From the Research
Next Steps for Patients with Cyclical Vomiting Syndrome
For patients with cyclical vomiting syndrome who do not respond to ondansetron (Zofran), several alternative treatment options can be considered:
- Aprepitant: A neurokinin 1 receptor antagonist that has been shown to be effective in preventing chemotherapy-induced vomiting or postoperative emesis, and has been used successfully in a patient with severe cyclic vomiting syndrome who failed oral ondansetron therapy 2.
- Combination of ondansetron and sumatriptan: Recommended for abortion of an acute vomiting episode, but other agents such as aprepitant and sedative agents can be considered when vomiting is refractory to initial treatments 3.
- Amitriptyline and cyproheptadine: Remain the standard of care for prophylaxis, with nutritional supplements such as carnitine and coenzyme Q10 showing efficacy in decreasing episodes and severity in small studies 3.
- Chlorpromazine: Has been used successfully in a patient with resistant cyclic vomiting syndrome who did not respond to many other agents 4.
- Addressing underlying conditions: Nonresponse to standard therapy in adult cyclic vomiting syndrome patients may be associated with co-existing migraine headache, psychiatric disorder, chronic narcotic and marijuana use, which should be addressed aggressively when symptom exacerbations continue during attempts to induce remission 5.
Considerations for Treatment
When considering treatment options for patients with cyclical vomiting syndrome who do not respond to ondansetron, it is essential to:
- Assess for underlying conditions: Such as migraine headache, psychiatric disorder, chronic narcotic and marijuana use, which may be contributing to the nonresponse to standard therapy 5.
- Consider novel therapies: Such as aprepitant, which has shown promise in treating cyclic vomiting syndrome, and other agents targeting the endocannabinoid system, which may offer potential for transforming the care of these patients 2, 6.