Effectiveness Not Established

N-acetyl Cysteine

for Mucositis

N-acetyl cysteine is derived from the amino acid L-cysteine and is used as a pharmaceutical drug as well as in nutritional support. It can be can be administered via IV or inhaled. It has multiple uses in medicine, and its primary uses are in acetaminophen overdose and as a mucolytic agent. It has been studied in the treatment of cancer treatment-related mucositis. 

Research Evidence Summaries

Moslehi, A., Taghizadeh-Ghehi, M., Gholami, K., Hadjibabaie, M., Jahangard-Rafsanjani, Z., Sarayani, A., ... Ghavamzadeh, A. (2014). N-acetyl cysteine for prevention of oral mucositis in hematopoietic SCT: A double-blind, randomized, placebo-controlled trial. Bone Marrow Transplantation, 49(6), 818–823. 

Study Purpose

To determine the effect of n-acetyl cysteine (NAC) on the incidence and severity of oral mucositis glutathione peroxidase-1 activity

Intervention Characteristics/Basic Study Process

Patients were randomized to groups by a researcher not involved in the assessment of study outcomes. This same researcher also provided either the study drug or the placebo to the administrating nurse. Nurses were not blinded to the study groups, but treating physicians and those involved in the assessment of study data were blinded to the groups.

The study group was given NAC at 100 mg/kg of body weight diffused in 500 ml dextrose solution 5%. The drug was infused over a three-hour period beginning on the same day as high-dose chemotherapy (HDC) and continuing until 15 days post-transplantation. A placebo infusion was given to control subjects. Patients were assessed daily beginning the first day of HDC and continuing for 21 days post-transplantation or until mucositis resolved.

Sample Characteristics

  • N = 80
  • AVERAGE AGE = 33.5 years
  • MALES: 68.7%, FEMALES: 31.3%
  • KEY DISEASE CHARACTERISTICS: Acute myeloid leukemia 51.3%, acute lymphoblastic leukemia 43.8%, and myelodysplastic syndrome 4.9%


  • SITE: Single-site

Phase of Care and Clinical Applications

PHASE OF CARE: Active antitumor treatment

Study Design

Double-blind, randomized, placebo-controlled study

Measurement Instruments/Methods

  • World Health Organization (WHO) Oral Toxicity Scale


The overall incidence of all grades of oral mucositis (OM) did not differ between groups. The incidence of severe OM (grades 3 and 4) was significantly lower in the intervention group (23.7%) compared to the control group (45.2%) (p = 0.04). No patients in the intervention group developed grade 4 mucositis while seven patients in the control group developed grade 4 mucositis. Patients who received NAC had a significantly shorter duration of mucositis (6.24 days) compared to controls (8.12 days) (p = 0.02). There was no difference in the time to onset of mucositis between groups. The use of parenteral opioid analgesics was not significantly different between study groups.


In this study, patients in the intervention group experienced less severe oral mucositis. No patients who received NAC developed grade 4 mucositis. Additionally, patients receiving NAC had a shorter duration of oral mucositis compared to controls. There was, however, no difference in the overall incidence of all grades of mucositis (grades 0–4) and no difference in the time to onset of mucositis between groups.


  • Small sample (< 100)

Nursing Implications

NAC was shown to decrease the severity and duration of OM and was well tolerated by the patients in this study. Patients undergoing transplant can benefit from these findings as the toxicities of increased pain, potential for infection, impaired nutritional intake, and prolonged hospitalization can be decreased. Nurses should carefully asses patients for the presence of mucositis during treatment with HDC and continue assessments until mucositis has resolved.