Efficacy, safety and tolerance of subcutaneous injection of high dosages of diclofenac in patients with neuropathic non-cancer pain and neuropathic cancer pain: Data from a clinical setting

Diclofenac sodium is widely used for its anti-inflammatory and analgesic effects in the symptomatic treatment of acute and chronic inflammatory and painful conditions. The present observational study was carried out to investigate efficacy, safety, and tolerability of a new subcutaneous (SC) 75 mg/1 mL diclofenac hydroxypropyl-β-cyclodextrin (HPβCD) formulation for the treatment of neuropathic pain both in patients without cancer and in patients with cancer. A total of 105 outpatients and inpatients with moderate to severe neuropathic pain related to cancer (CP) and non-cancer (NCP), were selected if Numeric Rating Scale (NRS) ⩾7 and Pain Detect (PD) >16, and treated with 75 mg/1 mL SC HPβCD, according to a real clinical setting. The analgesic efficacy of the treatment, which was assessed during the study by questionnaire, was expressed in terms of reduction of 30–50% and >50% of baseline pain (NRS), after 1.5 h and 4 h from drug administration; tolerability and safety were assessed as well, and adverse events were recorded by an expert panel. In our study, a significant reduction in pain intensity (PI) after 1.5 h and after 4 h was observed for both groups of patients (CP and NCP). Different from what was detected in the CP group, a further and significant reduction of PI was obtained in the NCP group at 4 h (P