Tag: nausea

Less Is More: Low-Dose Olanzapine Curbs Chemo-Induced Nausea Without the Sedation

A recent clinical trial demonstrates 5mg olanzapine’s safety and efficacy for chemotherapy-induced nausea and vomiting

Researchers from Japan found that a 5mg dose of olanzapine, taken after chemotherapy, significantly reduces nausea and vomiting in breast cancer patients, while minimising sedation and cutting costs. This patient-centred approach could reshape global standards for antiemetic care. Credit: Prof Mitsue Saito from Juntendo University, Japan

Chemotherapy-induced nausea and vomiting can severely impact patients’ quality of life and treatment adherence. In a major clinical trial, researchers from Japan tested whether a low, 5mg dose of olanzapine taken at home after chemotherapy could reduce these side effects without causing heavy sedation. The study found that this approach significantly improved outcomes compared to placebo, offering a safer, more affordable strategy that could reshape supportive cancer care, especially in outpatient and resource-limited settings.

Chemotherapy-induced nausea and vomiting are among the most distressing side effects of anti-cancer treatment, particularly for those receiving highly emetogenic regimens such as anthracycline plus cyclophosphamide combinations. This major side effect compromises a patient’s quality of life and willingness to continue therapy. Therefore, there is a crucial need to devise an effective antiemetic management approach for optimizing cancer care and patient well-being.

Against this backdrop, a new study, led by Professor Mitsue Saito and Dr. Hirotoshi Iihara from Japan, was made available online on June 17, 2025, and published in Volume 26, Issue 7 of the journal The Lancet Oncology on July 1, 2025, examined whether a 5mg dose of olanzapine taken at home after chemotherapy could reduce nausea and vomiting in patients with breast cancer while minimising the sedative effects associated with the standard 10mg dose.

“While multiple studies have examined 10mg of olanzapine and confirmed its effectiveness for nausea control, at this dose it often causes sedation, raising safety concerns,” explains lead author Prof Saito. “Beyond the commonly observed sedation, olanzapine at the 10 mg dose can cause serious adverse effects, including sedative effects such as daytime sleepiness and loss of consciousness.”

“The study was inspired in part by three patients with breast cancer who attended an antiemetic guideline meeting at MASCC 2015 in Copenhagen. They spoke about the burdensome sedative side effects of olanzapine, a concern that helped shape the trial’s patient-centred design,” says Prof Saito.

This phase 3, double-blind, placebo-controlled trial enrolled 500 female patients with breast cancer in Japan receiving outpatient anthracycline plus cyclophosphamide-based chemotherapy. Participants were randomly assigned to receive either olanzapine 5mg or placebo in combination with standard triplet antiemetic therapy (palonosetron, dexamethasone, and an NK-1 receptor antagonist). The olanzapine 5mg was taken at home after chemotherapy to help avoid sedation during hospital travel or treatment.

“This study uniquely investigates the timing of olanzapine 5mg administration, given within 5 hours post-chemotherapy administration and before the evening meal, to reduce sedation during hospital visits and transportation. This approach takes into account the onset of nausea and vomiting reported in previous studies. Among highly emetogenic chemotherapies, there is a significant difference between cisplatin, which usually requires hospitalisation for treatment, and other chemotherapies such as anthracycline-based regimens that are typically administered on an outpatient basis,” says Dr Iihara. The primary endpoint of the study was to investigate the proportion of patients achieving complete response, defined as no vomiting and no rescue medication use during the overall phase (0–120 hours post-anthracycline plus cyclophosphamide initiation).

The results demonstrated significant improvement, with 58.1% of patients in the olanzapine 5mg group achieving a complete response during the first 5 days after chemotherapy, compared to only 35.5% in the placebo group. Benefits also extended to delayed nausea and vomiting across a 7-day observation period.

While some patients reported drowsiness, the incidence of severe or very severe concentration impairment was low, occurring in 10% of patients in the olanzapine 5mg group vs 14% in the placebo group. Additionally, no major adverse events were observed in either group, indicating that there were no treatment-related deaths in either group.

The olanzapine 5mg dose offers an important financial and clinical advantage over the commonly used 10mg. By reducing side effects and cost, this strategy may make antiemetic treatment more accessible, particularly in lower-resource settings.

These new findings suggest that an olanzapine 5mg regimen, especially when administered after chemotherapy, can be just as effective, with fewer side effects. Although the study focused on Japanese women with breast cancer, the results are expected to influence international practices and future guideline updates.

In addressing both physical and financial toxicity and putting patients’ voices at the centre of the research, this trial represents more than a treatment tweak. It’s a step toward more humane, equitable cancer care.

Source: Juntendo University

Alleviating Motion Sickness with a Unique Sound

Photo by Pawel Czerwinski on Unsplash

Researchers at Nagoya University Graduate School of Medicine has discovered that using “a unique sound stimulation technology” – a device that stimulates the inner ear with a specific wavelength of sound – reduces motion sickness. Even a single minute of stimulation reduced the staggering and discomfort felt by people that read in a moving vehicle. The results, published in Environmental Health and Preventive Medicine, suggest a simple and effective way to treat this common disorder.

“Our study demonstrated that short-term stimulation using a unique sound called ‘sound spice®’ alleviates symptoms of motion sickness, such as nausea and dizziness,” said study leader Takumi Kagawa. “The effective sound level falls within the range of everyday environmental noise exposure, suggesting that the sound technology is both effective and safe.”

The discovery is an important expansion of recent findings about sound and its effect on the inner ear. Increasing evidence has suggested that stimulating the part of the inner ear associated with balance using a unique sound can potentially improve balance. Using a mouse model and humans, the researchers identified a unique sound at 100Hz as being the optimal frequency.

“Vibrations at the unique sound stimulate the otolithic organs in the inner ear, which detect linear acceleration and gravity,” study leader Masashi Kato explained. “This suggests that a unique sound stimulation can broadly activate the vestibular system, which is responsible for maintaining balance and spatial orientation.”

To test the effectiveness of the devices, they recruited voluntary participants who were exposed to the unique sound. Following the stimulation, motion sickness was induced by a swing, a driving simulator, or riding in a car. The researchers used postural control, ECG readings, and Motion Sickness Assessment Questionnaire results to assess the effectiveness of the stimulation.

Exposure to the unique sound before being exposed to the driving simulator enhanced sympathetic nerve activation. The researchers found symptoms such as “lightheadedness” and “nausea,” which are often seen with motion sickness, were alleviated.

“These results suggest that activation of sympathetic nerves, which are often dysregulated in motion sickness, was objectively improved by the unique sound exposure,” Kato said.

“The health risk of short-term exposure to our unique sound is minimal,” Kagawa said. “Given that the stimulus level is well below workplace noise safety standards, this stimulation is expected to be safe when used properly.”

Their results suggest a safe and effective way to improve motion sickness, potentially offering help to millions of sufferers. The researchers plan to further develop the technology with the aim of practical application for a variety of travel situations including air and sea travel.

Source: Nagoya University

Mapping the Neural Pathways for Vomiting after Eating Infected Food

Photo by Kyle Glenn on Unsplash

The urge to vomit after eating contaminated food is the body’s natural defensive response to get rid of bacterial toxins. However, exactly how the brain initiates the response has remained a mystery. Now, researchers have mapped out the detailed neural pathway of the defensive responses from the gut to the brain in mice. The study, published in the journal Cell, could help scientists develop better anti-nausea medications for cancer patients who undergo chemotherapy.

Many foodborne bacteria produce toxins in the host after ingestion. After sensing their presence, the brain will initiate a series of biological responses, including vomit and nausea, to expel the substances and develop an aversion toward foods that taste or look the same.

“But details on how the signals are transmitted from the gut to the brain were unclear, because scientists couldn’t study the process on mice,” says Peng Cao, the paper’s corresponding author at the National Institute of Biological Sciences in Beijing. Rodents cannot vomit, so scientists have been studying vomit in other animals like dogs and cats, but these animals are not comprehensively studied and thus failed to reveal the mechanism of nausea and vomiting. However, Cao and his team noticed that while mice don’t vomit, they retch – meaning they also experience the urge to vomit without throwing up.

The team found that after receiving Staphylococcal enterotoxin A (SEA), which is a common bacterial toxin produced by Staphylococcus aureus that also leads to foodborne illnesses in humans, mice developed episodes of unusual mouth opening. Mice that received SEA opened their mouths at angles wider than those observed in the control group, where mice received saline water. Moreover, during these episodes, the diaphragm and abdominal muscles of the SEA-treated mice contract simultaneously, a pattern seen in dogs when they are vomiting. During normal breathing, animals’ diaphragm and abdominal muscles contract alternatively.

“The neural mechanism of retching is similar to that of vomiting. In this experiment, we successfully build a paradigm for studying toxin-induced retching in mice, with which we can look into the defensive responses from the brain to toxins at the molecular and cellular levels,” Cao says.

In mice treated with SEA, the team found the toxin in the intestine activates the release of serotonin, a type of neurotransmitter, by the enterochromaffin cells on the lining of the intestinal lumen. The released serotonin binds to the receptors on the vagal sensory neurons located in the intestine, which transmits the signals along the vagus nerves from the gut to a specific type of neurons in the dorsal vagal complex – Tac1+DVC neurons – in the brainstem. When Cao and his team inactivated the Tac1+DVC neurons, SEA-treated mice retched less compared with mice with normal Tac1+DVC neuron activities.

In addition, the team investigated whether chemotherapy drugs, which also induce defensive responses like nausea and vomiting in recipients, activate the same neural pathway. They injected mice with doxorubicin, a common chemotherapy drug. The drug made mice retch, but when the team inactivated their Tac1+ DVC neurons or serotonin synthesis of their enterochromaffin cells, the animals’ retching behaviours were significantly reduced.

Cao says some of the current anti-nausea medications for chemotherapy recipients, such as Granisetron, work by blocking the serotonin receptors. The study helps explain why the drug works.

“With this study, we can now better understand the molecular and cellular mechanisms of nausea and vomiting, which will help us develop better medications,” Cao says.

Next, Cao and his colleagues want to explore how toxins act on enterochromaffin cells. Preliminary research shows that enterochromaffin cells don’t sense the presence of toxins directly. The process likely involves complex immune responses of damaged cells in the intestine.

“In addition to foodborne germs, humans encounter a lot of pathogens, and our body is equipped with similar mechanisms to expel these toxic substances. For example, coughing is our body’s attempt to remove the coronavirus. It’s a new and exciting field of research about how the brain senses the existence of pathogens and initiates responses to get rid of them.” Cao says, adding that future research may reveal new and better targets for drugs, including anti-nausea medicines.

Source: ScienceDaily