Table 1.

Inclusion and exclusion criteria

Inclusion criteria

1. Patients who have completed radiation therapy or concurrent chemotherapy and radiation therapy for nasopharyngeal carcinoma (clinical staging of tumor based on AJCC staging (8th edition) T1–4, N0–3, M0).

2. Patients age 20 years old to 85 years old.

3. Two months has elapsed since last dose of chemotherapy or radiotherapy.

4. Karnofsky performance score more than 70%.

5. Patients complaining of xerostomia.

Exclusion criteria

1. Those contraindicated to using mouthwash (established allergy to lactoperoxidase, lysozyme, glucose oxidase lactoferrin, cetylpyridinium chloride, and xylitol).

2. Patients with residual or recurrent disease.

3. Patients who received intensity-modulated radiation therapy.

4. Patients with ongoing oral mucositis (WHO Oral Mucositis grading I to IV).

5. Patients with facial, glossopharyngeal. vagus and hypoglossal nerve palsy/ paresis.

6. Patients who had any form of concurrent treatment protocols (hormonal, alternative, antiviral, sialogogues, or photodynamic therapy) during the study duration.

7. Patients with autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, and Sjớgren syndrome.