Objective:

To explore safety and effectiveness of anti-emetic strategies in Alexander disease (AxD). 

Background:

Emesis is a frequent symptom in AxD and leads to inadequate intake and food avoidance behaviors. As a result, weight loss and failure to thrive are common in AxD. We explored emesis treatment strategies to determine their relative benefits and side effects in clinical practice.

Design/Methods:

Medical records of patients with AxD (<21 years) participating in a natural history cohort study were reviewed for history of emesis, difficulty with weight gain, and medications. Patients were retrospectively evaluated for response to medication, which was defined as a clinically meaningful decrease in emesis. Treatment failure was defined as no improvement, worsened emesis, clinically significant weight loss, or presence of an intolerable side effect. Deceased patients, patients with a Nissen fundoplication, and patients with insufficient longitudinal data were excluded. Fisher’s exact tests were used to compare response rates of valproic acid to those of anti-reflux medications (proton pump inhibitors, H2 antagonists analyzed together) or cyproheptadine.

Results:

Among 59 subjects with vomiting, 34 subjects met inclusion criteria. Emesis was treated with multiple anti-reflux medications (N=24), cyproheptadine (N=19), and valproic acid (VPA, N=22). Overall, 48% of patients responded to multiple anti-reflux medications, 32% responded to cyproheptadine, and 95% responded to VPA. VPA had a higher success rate in reducing emesis compared to multiple reflux medications (p=0.0001) or cyproheptadine (p<0.0001). Adverse effects from VPA included bone fractures (N=1) in a non-ambulatory patient, hyperammonemia (N=2) which resolved with dose lowering, and mild hair loss (N=2).

Conclusions:

Recognizing the limitations of retrospective review, 95% of AxD patients on VPA showed improvements in emesis and weight gain. Response rates to VPA were greater compared to anti-reflux medications or cyproheptadine. VPA is well tolerated overall, although use should be monitored for known adverse effects.