Italian Study Shows Low-Dose Morphine Better Than Weak Opioids in Relieving Moderate Cancer Pain
In an Italian trial reported in the Journal of Clinical Oncology, Bandieri et al found that low-dose morphine provided better and more rapid pain relief than weak opioids in patients with moderate cancer pain.
Study Details
In the open-label 28-day trial, 240 adults with moderate cancer pain from 17 Italian sites were randomized to receive daily low-dose morphine (n = 118) or weak opioid treatment (n = 122). The median dose of morphine was 30 mg; among patients in the weak-opioid group, 84% received a fixed combination of codeine (81%) or tramadol and 16% received tramadol alone. The primary outcome was the proportion of patients with a ≥ 20% reduction in pain intensity on a numerical rating scale.
Pain Response
Response occurred in 88.2% of the low-dose morphine group vs 57.7% of the weak-opioid group (odds ratio [OR] = 6.18, P < .001), with 82.7% vs 47.0% having a clinically meaningful reduction (≥ 30%; OR = 5.40, P < .001) and 75.5% vs 41.9% having a highly meaningful reduction (≥ 50%; OR = 4.27, P < .001). Outcomes were nearly identical in analysis, adjusting for pain intensity at baseline, age, gender, Karnofsky performance score, adjuvant therapy, rescue therapy, cancer type, and anticancer treatment. A benefit of low-dose morphine was observed as early as 1 week (80.9% vs 43.6%, P < .001).
The general condition of patients based on the Edmonton Symptom Assessment System overall symptom score was better in the morphine group (median score = 10 vs 19, P < .001). Both treatments were well tolerated; five patients in each group discontinued treatment due to adverse events (three in each) or poor tolerability (two in each). No difference in intensity or frequency of opioid-related symptoms was observed.
The investigators concluded: “In patients with cancer and moderate pain, low-dose morphine reduced pain intensity significantly compared with weak opioids, with a similarly good tolerability and an earlier effect.”
The study was supported by Azienda Ospedaliero Universitaria Policlinico and USL Modena and Direzione Generale Sanità e Politiche Sociali, Regione Emilia-Romagna.
Mario Luppi, MD, PhD, of Azienda Ospedaliero Universitaria Policlinico, Modena, Italy, is the corresponding author of the Journal of Clinical Oncology article.
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