evaluate preventive and therapeutic effects of Rebamipide gargle on reducing incidence of oral mucositis in comparison with benzydamine HCL mouthwash.

Oral mucositis is a common and potentially dangerous complication of anticancer treatment. Inflammation and ulcerations of the oral mucosa make swallowing and, thereby, eating and drinking, difficult or even impossible, leading to anorexia and weight loss(Araújo et al., 2018) .There is a serious risk of infections and even sepsis, particularly in immune-ompromised patients. OM is associated with severe pain, affects the quality of life, and often requires reduction or suspension of chemotherapy and/or radiotherapy, thereby decreasing the relative dose intensity, which may worsen prognosis (Shumsky et al., 2019).

Benzydamine hydrochloride is a widely used drug in dentistry , a non-steroidal anti-inflammatory drug, has shown topical anti-inflammatory, analgesic, anaesthetic and antimicrobial effects and is used to attenuate inflammatory conditions like radiation -induced oral mucositis or chemotherapy-induced oral mucositis (Nithin, et al.,2018). In addition to this, Benzydamine HCL is available on the Egyptian market and its price is economical .Rebamipide is a drug used for the treatment of gastritis and gastric ulcer. The mechanisms involved in the anti-ulcer and cytoprotective effects of rebamipide have been reported to include an effect on prostaglandin E2 synthesis via COX-2 expression (Udagawaet al ., 2003), up-regulation of growth factors and their receptors such as EGF and HGF ,induction of mucus secretion ,anti-free radical effects and inhibition of the production of inflammatory cytokines such as IL-1, IL-8, and TNF-α (Yasuda et al., 2011).

Different treatment options and drugs have been tested in OM, only some of which exhibited clinical relevance such as oral cryotherapy, keratinocyte growth factor and amino acids enriched diets. Therefore, there is a clear requirement for new approaches to the prevention and effective treatment of OM (Mallick, Benson, & Rath, 2016)

In 2019 a meta-analysis performed by Akagi and his colleagues (Akagi et al., 2019) showed that gargling treatment with Rebamipide is superior to placebo for the development of mucositis and stomatitis due to chemo-radio-therapy, especially for severe cases of Grade 3 or higher. However, in order to confirm these trials, further well-designed analyses are needed, and evaluation of adverse events in observational studies are also required.

Inclusion Criteria:Male and female patients with head and neck cancer and who will be prescribed radiotherapy at least 60 Gy (Roopashri et al., 2011).

• Patients who will sign an informed consent,
• Patients older than 18 years of age,
• Patients having normal renal and liver functions

Exclusion Criteria:• . Use of dentures, or having any source of infection in the mouth.

• Allergy to rebamipide or benzydamine hydrochloride(Nithin et al., 2018) .

Data collection and storage will be the responsibility of the candidate. Patient's personal information will be available to the candidate only. While the clinical and analytical data will be available to the entire research team.