Retrospective review of patients treated for cyclic vomiting syndrome with topiramate.

Abstract

Practice guidelines recommend topiramate as second-line treatment for the prevention of moderate-severe cyclic vomiting syndrome (CVS) in adults. However, data are limited to small studies in children. To characterise the response to topiramate as prophylactic therapy in adults with CVS. We conducted a retrospective review of patients with CVS. Clinical characteristics, number of CVS episodes, emergency department (ED) visits, and hospitalisations the year before and after initiating topiramate were recorded. Response was defined as a global improvement in symptoms or >50% reduction in the number of CVS episodes, ED visits or hospitalisations. Sixty-five percent (88/136) of patients responded to topiramate in an intent-to-treat analysis. There was a significant decrease in the annual number of CVS episodes (18.1 vs 6.2, P<0.0001), CVS-related ED visits (4.3 vs 1.6, P=0.0029), and CVS-related hospitalisations (2.0 vs 1.0, P=0.035). Logistic regression revealed that higher doses of topiramate, longer use of topiramate (≥12months) and topiramate as monotherapy were associated with a response to treatment. Anxiety was associated with non-response to topiramate. Fifty-five percent of patients experienced side effects, and 32% discontinued the medication as a result. The most common side effects were cognitive impairment (13%), fatigue (11%) and paresthesia (10%). This represented a refractory group with topiramate being initiated in patients (92%) who had failed treatment with tricyclic antidepressants (TCAs). Topiramate may be an effective second-line prophylaxis for patients with moderate-severe CVS, but its use is limited by side effects. Efforts to develop better-tolerated therapies for CVS are warranted.