Anticipatory nausea and vomiting associated with cancer chemotherapy

Fifty adult oncology outpatients receiving chemotherapy were surveyed to assess their experiences with chemotherapy-associated nausea and vomiting. Of patients who noted post-chemotherapy nausea with or without vomiting, 46% reported anticipatory nausea. The anticipatory symptoms developed after the onset of post-chemotherapy neausea. Patients experiencing anticipatory symptoms had received chemotherapy over a significantly longer period of time than had the patients with post-treatment nausea only. Of these patients who had noted post-chemotherapy nausea with or without vomiting for two or more months, 50% reported pre-treatment nausea with or without vomiting. There was no tendency toward anticipatory symptoms according to age, sex, race, educational level, disease, or type of chemotherapy. Thoughts of chemotherapy, sights, specific odors and tastes evoked anticipatory symptoms. Pre-treatment or anticipatory nausea and vomiting are probably a manifestation of classical (Pavlovian) conditioning.