The enrolled head and neck squamous cell carcinoma patients in this study received high-dose multiday chemotherapy with cisplatin and synchronous radiation therapy, which had a high risk of nausea and vomiting. On the first and third days, they took Netopitam Palonosetron capsules and dexamethasone to reduce the incidence of acute vomiting. The aim of this study is to evaluate the antiemetic effect of Netopitam Palonosetron capsules and to explore the effectiveness of using Netopitam Palonosetron capsules again for antiemetic treatment during the study period when breakthrough vomiting occurs.

Inclusion Criteria:

1. Male or female, aged 18-75 years old;
2. Head and neck tumors confirmed by histology or cytology (including oral cancer, oropharyngeal cancer, hypopharyngeal cancer, and laryngeal cancer);
3. Receive radical synchronous radiotherapy and chemotherapy;
4. The Eastern Oncology Collaborative Group (ECOG) physical fitness score of the subjects was ≤ 2 points;
5. Adequate organ and bone marrow function;
6. The expected life is at least 12 weeks;
7. Pregnant or fertile patients (male or female) use reliable contraceptive measures;
8. When screening female patients with potential pregnancy, the pregnancy test must be negative;
9. The subjects voluntarily and strictly comply with the requirements of the research protocol and sign a written informed consent form.

Exclusion Criteria:

1. Recurrent and metastatic head and neck tumors;
2. Previously underwent tumor resection surgery for treatment;
3. Patients with platinum drug intolerance;
4. Receiving any known or potential antiemetic medication within 24 hours prior to the first day, or experiencing symptoms of vomiting, retching, or mild nausea within 24 hours prior to the first day;
5. Take NK1（neurokinin-1） receptor antagonists or any study medication within 4 weeks before the start of the experiment;
6. Use CYP3A4 inducer within 4 weeks before chemotherapy, and use CYP3A4 substrate or strong or moderate CYP3A4 inhibitor within 1 week;
7. Serious cardiovascular, pulmonary, diabetes, mental and other diseases;
8. Pregnant or lactating women, patients with fertility who are unwilling or unable to take effective contraceptive measures;
9. Drug and/or alcohol abuse;
10. Hypocalcemia or any other condition that may cause vomiting;
11. There are significant factors that affect the absorption of oral medication, such as chronic diarrhea and intestinal obstruction;
12. The subject has allergic reactions to Netopitam Palonosetron capsules or any of their excipients;
13. Within 30 days prior to the baseline visit, the subject participated in another clinical study and used any exploratory drugs or devices; Allow participation in observational research;
14. The researcher determines other situations that may affect the progress of clinical research and the determination of research results.