Head and neck cancer corresponds to tumors located in the upper aerodigestive tract, such as the oral cavity, pharynx and larynx. The most effective treatment consists of high dose of cisplatin chemotherapy and radiotherapy, however, their use is limited due to toxicities caused mainly by oxidative stress. The objective of this study will be evaluate the use of n-acetylcysteine attenuating cisplatin-induced toxicities by oxidative stress in head and neck cancer patients. This is a randomized double-blind placebo-controlled clinical trial with consecutive sampling that will be conducted at Oncology Department of Clinic Hospital / University of Campinas (UNICAMP). Head and neck cancer patients who will begin cisplatin antineoplastic treatment (80-100mg/m2 on days 1, 22 and 43) and concurrent radiotherapy will be included in this research. They will be studied in 2 groups (n-acetylcysteine and placebo). All patients will be evaluated in relation to cisplatin induced hematologic and gastrointestinal disorders, nephrotoxicity, ototoxicity, and hepatotoxicity; plasmatic and cellular oxidative stress; quality of life; and pharmacoeconomic evaluation. Results will be statistically analysed using Chi-square, Fisher, Mann-Whitney, and ANOVA for repeated measures tests (p<0.05.)

Inclusion Criteria:

• head and neck cancer
• anticancer treatment - cisplatin (80 to 100 mg/m²) plus radiotherapy
• patients without previous treatment of head and neck cancer (surgery, chemotherapy and radiotherapy)

Exclusion Criteria:

• severe psychiatric diseases
• impossibility of verbal communication
• without caregivers or companions