Do Oral Side Effects Affect Fentanyl Delivery in Head & Neck Cancer Patients?

Patients treated for head and neck cancers are at a high risk for treatment-related side effects. It has been reported that over 90% of patients undergoing chemotherapy or bioradiotherapy will experience mucositis and xerostomia, which requires treatment with opioids. Given the high rates of these unwanted side effects, researchers of a recent study evaluated the absorption of sublingually delivered fentanyl (SDL) in this patient population.

Erin McMenamin, CRNP, a radiation oncology nurse practitioner at the Abramson Cancer Center of Penn Medicine in Philadelphia, who was not involved with the research, spoke with Cancer Network about this study. “Mucositis is an expected consequence of chemotherapy and radiation therapy to the head and neck. Severity depends on the location, dose, and type of concurrent chemotherapy. Opioids are generally the treatment of choice, due to efficacy and the potential for unwanted side effects from other medications. Xerostomia is also a risk due to treatment. As a result of improvements in technology, a portion of salivary function is now generally salvageable,” she said.

The study included 13 head and neck cancer patients who were being treated with chemotherapy or bioradiotherapy for cancers of the oropharynx, hypopharynx, larynx, or combined oropharynx/larynx, with more than half having cervical lymph node metastases; all patients were ultimately diagnosed with common terminology criteria (CTC) grade ≥ 2 mucositis during treatment.

Primary and secondary endpoints included evaluation of the relative difference between systemic exposure to fentanyl area under the curve (AUC) at baseline and fentanyl AUC in the presence of mucositis grade ≥ 2, and the relative difference between fentanyl AUC at baseline and fentanyl AUC in the presence of xerostomia, respectively.

“The typical absorption of transmucosal fentanyl is 10 to 15 minutes, which is when patients note onset of relief of pain. Studies to date have not included duration of action of transmucosal fentanyl,” noted McMenamin.

Using pharmacokinetic samples, researchers determined that in comparison to baseline samples, patients with mucositis experienced a 12.7% higher AUC when given fentanyl (n = 13; 95% CI, −10.7% to +42.2%; P = .29). The study participants with xerostomia experienced a 22.4% lower AUC (n = 8; 95% CI, −51.9% to +25.3%; P = .25) when compared with their baseline samples.

With these data, researchers determined that chemotherapy or bioradiotherapy–related grade ≥ 2 mucositis or the presence of xerostomia did not cause an alteration in SDL’s systemic exposure, and patients with these side effects could safely undergo pain management with SDL fentanyl.

However, McMenamin pointed out a limitation of the study. “The authors performed quantitative statistics on a sample that was not adequately powered. Unfortunately, I would not consider these results to be valid, given the lack of a power analysis and underpowered study,” she said.