Original Article Parecoxib as an adjunct therapy for the treatment of refractory non-surgical cancer pain Arti Thakerar 1 , Seamus Dines-Muntaner 2 , Tijana Trifunovich 3 , Marliese Alexander 1,4, * and Sonia Fullerton 5, * Abstract Background: Evidence for the use of short-term daily parenteral parecoxib for refractory or uncontrolled non-surgical cancer pain is limited. This study aimed to characterise the real-world off-label use and report on clinical experiences in an Australian cancer cohort. Methods: Eligible patients received at least one dose of parecoxib of an intended three-day course between October 2015 and December 2018. Data were collected to characterise the parecoxib treatment cohort (cancer diagnosis, metas- tases, sites and types of pain and prior analgesia). Parecoxib-related adverse events, pain scores (worst and median), and concurrent opioid use were assessed at 24 h pre (T0) and 24 (T1), 48 (T2), 72 (T3) and 96 h (T4) post first parecoxib dose. Results: Sixty-five patients (39 males and 26 females) and 68 courses of parecoxib (three patients treated twice) were included in analyses: metastatic disease (86%), bone pain (54%) and taking 3 classes of analgesic medications (69%). Pain types varied (46% non-specific, 22% neuropathic and 32% other). Most (94%) received parecoxib by subcutaneous administration. Following parecoxib, median 24-h pain scores and worst pain scores improved for 59% (40/68) and 50% (34/68) of patients, respectively. In the first 24h (T0 to T1), median (4 vs. 2, p < 0.01) and worst (6 vs. 5, p < 0.01) pain scores were reduced and sustained to T4 (4 vs. 2.5, p ¼ 0.01). Breakthrough analgesia requirements reduced for 63% (43/68) of patients, while total concurrent opioid use remained constant. Mean/median oral morphine equivalence for T0 vs. T1 was 111 mg/75 mg vs. 162 mg/90 mg, (p > 0.8). Two patients ceased parecoxib due to renal/liver function abnormalities and two experienced mild injection-site reactions. Conclusions: In this real-world study, parecoxib was utilised as adjunctive therapy in a select patient cohort to contribute to reduced pain scores with no new safety signals. Prospective randomised studies in larger cohorts would improve understanding of the effects of parecoxib. Keywords Cancer, cancer pain, pain, palliative care, parecoxib Date received: 27 August 2019; revised: 4 December 2019; accepted: 5 December 2019 Introduction Parecoxib sodium is a non-steroidal anti-inflammatory drug (NSAID) that is currently used off licence in con- junction with other analgesics, for the treatment of non-surgical refractory cancer pain in palliative care. However, there is only weak evidence to support its use in the palliative care setting. 1 Parecoxib is the pro-drug of the active metabolite valdecoxib, a potent parenteral selective cyclo- oxygenase-2 inhibitor. Currently, it is licenced by the Australian Therapeutic Goods Administration in the perioperative setting for opioid-sparing analgesia in non-cardiac patients and by the US Food and Drug 1 Pharmacy Department, Peter MacCallum Cancer Centre, Melbourne, Australia 2 School of Clinical Sciences, Queensland University of Technology, Brisbane, Australia 3 Faculty Pharmacy and Pharmaceutical Sciences, Monash University, Parkville, Australia 4 Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, Australia 5 Parkville Integrated Palliative Care Service, Peter MacCallum Cancer Centre, Melbourne, Australia *These authors are joint senior authors. Corresponding author: Marliese Alexander, Pharmacy Department, Peter MacCallum Cancer Centre, Locked Bag 1, A’ Beckett Street, Melbourne, Victoria 8006, Australia. Email: Marliese.Alexander@petermac.org J Oncol Pharm Practice 0(0) 1–8 ! The Author(s) 2020 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/1078155219897744 journals.sagepub.com/home/opp