Italian Study Shows Low-Dose Morphine Better Than Weak Opioids in Relieving Moderate Cancer Pain


Key Points

  • Low-dose morphine provided better pain relief than weak opioids in patients with moderate cancer pain.
  • The advantage of morphine was evident early in treatment.

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. 

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.