Morphine versus oxycodone in pancreatic cancer pain: a randomized controlled study

According to experimental findings, oxycodone (OX) could have some advantages over morphine (MO) in clinical models of visceral pain. It was hypothesized that OX could have some advantages over MO in terms of efficacy and dose escalation in pancreatic cancer pain.

Sixty patients with pancreatic cancer with a pain intensity rating of 4/10 who required opioids were included in the study. Patients were randomized to receive 30 mg/d of sustained release oral MO or sustained release oral OX (20 mg/d). Opioid doses were increased according to the clinical needs. Daily doses of opioids, pain and symptom intensity were recorded at admission (T0) and at weekly intervals for the subsequent 4 weeks (T1, T2, T3, and T4), with an extension at 8 weeks (T8). Opioid escalation index (OEI) as percentage (OEI %) and in mg (OEI mg) was calculated.

Nineteen and 20 patients in groups OX and MO, respectively, were followed for the entire period of study (T4). No differences between groups were found in age (P=0.400), Karnofsky (P=0.667), or escalation indexes at T4 and T8 (OEImg, P=0.945 and OEI %, P=0.295). No statistical differences in pain and symptoms intensity between the groups were observed.

OX and MO provided similar analgesia and adverse effects with similar escalating doses in patients with pancreatic cancer pain, resembling observations reported in the general cancer pain population. The experimental hypothesis that OX would be superior to MO in the clinical model of pancreatic cancer pain was not confirmed.