Granisetron Transdermal System Improves Refractory Nausea and Vomiting in Gastroparesis

Symptoms of gastroparesis include nausea and vomiting, which can markedly diminish quality of life. Nausea and vomiting can also make treatment with oral antiemetics problematic. Our aim was to determine whether treatment-resistant nausea and vomiting in patients with gastroparesis improve after granisetron transdermal patch (GTP) therapy. In an open-label pilot study, patients with gastroparesis and symptoms of nausea and vomiting refractory to conventional treatment were treated with GTP. After 2 weeks, patients were asked to assess their therapeutic response using the Clinical Patient Grading Assessment Scale (CPGAS; +7 = completely better; 0 = no change; -7 = very considerably worse). Responders were defined as CPGAS score > 0, non-responders as a parts per thousand currency sign0. Patients (n = 36) were treated with GTP. Of these 36 patients, one patient discontinued treatment due to the GTP not adhering to the skin. Of the remaining 35 patients, 18 improved, 15 remained the same, and two worsened. The average CPGAS score was +1.8 +/- A 0.4 (SEM) (P < 0.05 vs 0). Of the 18 patients with improvement, the average CPGAS score was +3.7 +/- A 0.3 (SEM), corresponding to "somewhat" to "moderately better" improvement in nausea/vomiting. Side effects occurred in nine patients: four developed constipation, three patients had skin rash, and two reported headaches. GTP was moderately effective in reducing refractory symptoms of nausea and/or vomiting from gastroparesis in 50 % of patients. Mild side effects were reported by 25 % of patients. GTP may be an effective treatment for nausea and vomiting in gastroparesis, and further study is warranted.