Analgesic effects of indomethacin spray on drug-induced oral mucositis pain in patients with cancer: A single-arm cross-sectional study

Aims

Symptomatic treatment is insufficient for chemotherapy‐ or targeted therapy‐induced oral mucositis (OM) pain, and benzydamine mouthwash is not commercially available in Japan. We evaluated the analgesic effects of an in‐hospital preparation of 0.25% indomethacin spray (IMS) on anticancer drug‐induced OM pain.

Methods

This single‐arm prospective trial enrolled 20 patients (median age 62.0 years) with OM and numerical rating scale scores of ≥5 who were undergoing chemotherapy or targeted therapy in our hospital. Pain scores were recorded using a visual analog scale (VAS) before and 30 min after IMS administration. Pain relief (PR) scores were recorded at 15, 30, and 60 min after IMS administration; total PR after 60 min (TOTPAR₆₀) was calculated, and the mean PR score after 3 days (PR_3days) was determined.

Results

The median (interquartile range) OM grade of the participants was 2.0 (2.0–2.3). The VAS score decreased significantly at 30 min after IMS administration (p = .001). The median (interquartile range) TOTPAR₆₀ and PR_3days were 6.0 (3.8–7.3) and 2.0 (2.0–3.0), respectively.

Conclusions

IMS helped improve patients’ quality of life. The risk of systemic adverse effects was low because of the low dose administered. IMS effectively relieved anticancer drug‐induced OM pain and may be useful for immediate self‐medication.

[Evaluation of the Stability of Indomethacin Oral Spray in Two Different Formulation Conditions]

　Indomethacin (IM) oral spray is a hospital preparation that is used to reduce pain from oral mucositis induced by radiotherapy and chemotherapy. IM oral spray consists of IM (0.25%) dissolved in KH₂PO₄-NaOH buffer (Formulation A) or Formulation A containing xylitol (Xyl) and glycerin (Gly) (Formulation B). To clarify the stability of IM oral spray in two different formulation conditions, we evaluated the residual rates of IM in these formulations to determine the optimal storage temperature and shelf-life. IM oral spray was stored at freezer temperature (-20°C), refrigerator temperature (4°C) and room temperature (25°C) for up to 16 weeks after preparation. The residual rate of IM was determined by using HPLC. The residual rates of IM in Formulation A and Formulation B after storage for 16 weeks at freezer temperature were ≥95%. When stored at refrigerator temperature, the residual rate of IM in Formulation A was 96.1% after 12 weeks, and the residual rates of IM in Formulation B were 95.8% after 2 weeks, 90.1% after 4 weeks and 72.7% after 12 weeks. These results suggested that Formulation A is stable for at least 12 weeks when stored at 4°C. However, degradation of IM seemed to be accelerated in the formulation containing Xyl and Gly, suggesting that the expiration date should be shortened to 2 weeks at 4°C. In addition, both formulations were stable for at least 16 weeks in a freezer, indicating that long-term preservation is possible.

[Indomethacin Spray Preparation for the Control of Pain Associated with Stomatitis Caused by Chemotherapy and Radiotherapy in Cancer Patients]

Severe stomatitis caused by chemotherapy and radiotherapy is accompanied by severe pain and results in a poor quality of life. We used a spray preparation of indomethacin (IM; 0.25% IM dissolved in phosphate buffer, pH 7.4), a nonsteroidal anti-inflammatory drug (NSAID) to control the pain associated with stomatitis at the University of Tsukuba Hospital. This review specifically aimed to collect information on the use of the IM spray preparation, from our previous studies, to facilitate its proper use in a hospital setting. On studying the stability of the IM spray preparation, we concluded that the preparation should be kept in the refrigerator for daily use, and that it can be stored for at least 2 months at 4°C, and for 24 months at -20°C. To evaluate the efficacy of the IM spray preparation, we retrospectively surveyed its analgesic effects. Using the 10-grade Visual Analogue Scale in 23 patients, we found that pain associated with stomatitis was reduced from 10 to 4.7 after application of the spray. In conclusion, our study results on the stability and efficacy of the IM spray preparation have led to the proper use of the spray in cancer patients with stomatitis caused by chemotherapy and radiotherapy.