Olanzapine for cisplatin-induced hiccups: observations from a 338-patient study

Background: Several case reports suggest that olanzapine palliates hiccups. To our knowledge, however, no larger scale studies have confirmed that olanzapine prevents or palliatives hiccups. Hence, the current study sought to substantiate the conclusions from these earlier case reports. Methods: This multi-site single institution study focused on cisplatin-treated cancer patients because this chemotherapy agent is associated with hiccups and because olanzapine is often used as an antiemetic with this agent. Relevant data were extracted from medical records. Hiccup incidence shortly after chemotherapy was compared between olanzapine exposed and non-exposed patients. Other relevant variables were also assessed descriptively in an exploratory manner. Results: A total of 338 patients were studied. One hundred forty-one had received olanzapine and 197 had not. Twenty-one (6%) developed hiccups. Eleven (8%) of these patients with hiccups had received olanzapine, and 10 (5%) had not [odds ratio (OR): 1.58; 95% confidence interval (CI): 0.65–3.83; P=0.31]. Of note, hiccups were more often observed in men 17 of 188 (9%) than in women 4 of 150 (3%) (OR: 3.64; 95% CI: 1.20–11.02; P=0.01). Conclusions: Despite previous case reports and despite the relatively low incidence of hiccups in this study, it does not appear olanzapine prevents or palliates hiccups. The study of other promising agents is warranted. Furthermore, this study invites caution in relying on single case reports in making clinical decisions.