S1162 Off-Label Use of the Oral NK-1 Antagonist Aprepitant Is Beneficial in GI Disorders of Nausea and Vomiting: Prescription Profiles and Patient Characteristics

Introduction: The oral neurokinin-1 (NK1) antagonist aprepitant is approved for chemotherapy-induced and postoperative nausea and vomiting. Benefits of off-label aprepitant are described for gastrointestinal (GI) disorders of nausea and vomiting (N/V) such as gastroparesis and cyclic vomiting syndrome (CVS). In our health system, 29% of aprepitant prescriptions from 2021-23 were for such off-label GI indications. However, aprepitant prescription profiles, use of other N/V therapies, symptom reductions, and adverse events on aprepitant in specialized motility clinics caring for chronic N/V are poorly defined. Methods: A medical record search from a tertiary motility center identified adults who received aprepitant from 7/1/2021-6/30/2023 for GI disorders of N/V. GI diagnoses, aprepitant doses and duration of use, use of other N/V therapies, and outcomes on aprepitant were examined. Results: Fifty-seven patients (74% women; age 40 ± 16 yr) were prescribed aprepitant including 20 with gastroparesis (35%), 12 with CVS (21%), 6 with both conditions (11%), and 19 with other disorders (33%). Forty-three patients (75%) successfully obtained the drug; 34 (79%) filled prescriptions >3 months. Aprepitant dose packs (125 mg once/wk + 80 mg twice/wk) were most often taken (17/43 patients [40%]). Daily dosing was uncommon (6/43 patients [14%]). On average, patients used 5.0 + 2.3 other N/V therapies. Prior antiemetic use was universal—most often 5-HT3 antagonists (95%), dopamine D2 antagonists (79%), and histamine H1 antagonists (74%). Prokinetic agents and neuromodulators were taken by 61% and 72%, respectively. Cannabis was used by 45%. Reductions in N/V on aprepitant were noted by 29/43 patients (67%) similarly in gastroparesis vs CVS (P = 0.67). N/V decreased in 5/6 cases (83%) with daily dosing vs 24/37 (65%) with less frequent use (P = 0.65). Adverse effects (nausea, vomiting, diarrhea, fatigue) were noted by 7 patients (16%). Conclusion: Aprepitant was commonly prescribed in a specialty motility center for disorders such as gastroparesis and CVS Daily dosing was rare likely due to cost and insurance restrictions. Patients had already tried 5 other N/V therapies on average, reflecting their symptom burden. Nevertheless, two thirds of gastroparesis and CVS patients reported reduced N/V with infrequent side effects on aprepitant. These results support off-label inclusion of the NK1 antagonist aprepitant for treatment of these challenging conditions with chronic N/V.