Impact of Prophylactic Fentanyl Pectin Nasal Spray on Exercise-Induced Episodic Dyspnea in Cancer Patients: A Double-Blind, Randomized Controlled Trial.

CONTEXT: Episodic breathlessness is common and debilitating in cancer patients.

OBJECTIVES: In this pilot study, we examined the effect of prophylactic fentanyl pectin nasal spray (FPNS) on exercise-induced dyspnea, physiologic function, and adverse events.

METHODS: In this parallel, double-blind randomized placebo-controlled trial, opioid-tolerant patients performed three six-minute walk tests (6MWTs) to induce dyspnea. They were randomized to receive either FPNS (15%-25% of total daily opioid dose each time) or placebo 20 minutes before the second and third 6MWTs. We compared dyspnea Numeric Rating Scale (NRS, 0-10, primary outcome), walk distance, vital signs, neurocognitive function, and adverse events between the first and second 6MWTs (T2-T1) and between the first and third 6MWTs (T3-T1).

RESULTS: Twenty-four patients enrolled, with 96% completion. FPNS was associated with significant within-arm reduction in dyspnea NRS at rest (T2-T1: -0.9 [95% CI -1.7, -0.1]; T3-T1: -1.3 [95% CI -2.0, -0.5]) and at the end of a 6MWT (T2-T1: -2.0 [95% CI -3.5, -0.6]; T3-T1: -2.3 [95% CI -4.0, -0.7]), and longer walk distance (T2-T1 +23.8 m [95% CI +1.3, +46.2 m]; T3-T1: +23.3 m [95% CI -1.7, +48.2]). In the placebo arm, we observed no significant change in walk distance nor dyspnea NRS at rest, but significant reduction in dyspnea NRS at six minutes (T2-T1: -1.7 [95% CI -3.3, -0.1]; T3-T1: -2.5 [95% CI -4.2, -0.9]). Vital signs, neurocognitive function, and adverse effects did not differ significantly.

CONCLUSION: FPNS was safe, reduced dyspnea at rest, and increased walk distance in before-after comparison. The placebo effect was substantial, which needs to be factored in future study designs.

TRIAL REGISTRATION: ClinicalTrials.govNCT01832402.