Real-World Use of a Systemic Diclofenac Patch for Cancer Pain: A Retrospective Analysis of Prescription Patterns at a Single Japanese University Hospital.

Real-world evidence on systemic diclofenac patch use in cancer pain is limited. We described prescribing patterns in oncology practice. In this single-center retrospective descriptive study, we reviewed consecutive patients with cancer who received a systemic diclofenac patch (75 mg per patch) for cancer-related pain at a Japanese university hospital (n = 48). The usual regimen was two 75-mg patches once daily (150 mg/day); one patient started one 75-mg patch/day. Among 48 patients, 35 (73%) retained oral medication intake and 32 (67%) were receiving ongoing anticancer therapy at patch initiation. Gastroprotective agents were co-prescribed in 31 patients (65%), any acetaminophen in 29 (60%; scheduled acetaminophen in 28 [58%]), and opioids in 28 (58%). Transdermal fentanyl-containing regimens were observed in 9 patients (19%), whereas strict all-transdermal scheduled baseline analgesia was identified in 3 (6%). No recipient had documented clinically apparent gastrointestinal bleeding or symptomatic peptic ulcer during available follow-up. The systemic diclofenac patch was prescribed to selected patients with cancer-related pain in routine Japanese practice and was commonly incorporated into multimodal analgesic regimens. These findings describe prescribing patterns and chart-documented observations only; prospective studies with standardized outcomes are needed to clarify effectiveness, safety, and patient-centered impact.