A Randomised Controlled Study on the Use of Anti-inflammatory Drugs in Patients with Cancer Pain on Morphine Therapy: Effects on Dose-escalation and a Pharmacoeconomic Analysis

The role of non-steroidal anti-inflammatory drugs (NSAIDs) in cancer pain has been well established in the treatment of mild pain and in association with opioids in the treatment of moderate to severe pain. The aim of this study was to verify the effects of NSAIDs on morphine escalation in advanced cancer patients with pain followed-up at home and to assess the pharmacoeconomic implications. A prospective randomised controlled study was carried out in 156 consecutive advanced cancer patients with pain followed-up at home in the period December 1999-December 2000. In this group of patients, 47 were selected with pain progression after 1 week of opioid stabilisation. Patients were randomly assigned to one of two groups: group 'O' patients were treated with continuing opioid escalation according to their clinical needs; group 'OK' received ketorolac 60 mg/daily orally (p.o.) in three doses and then continued opioid escalation according to their clinical situation. Performance status, doses of morphine before and after starting treatment, mean weekly pain intensity (assessed by means of a numerical scale from 0 to 10), mean weekly symptoms intensity, adverse effects and pain mechanisms were recorded. Moreover, drug costs per day in both groups were calculated. Patients who received ketorolac in addition to morphine showed a better analgesia after a week in comparison to the group treated with morphine only (P=0.005). Thereafter, morphine escalation was slower and the maximum morphine dose was lower in the group treated with ketorolac. The incidence and the severity of gastric discomfort was more evident in patients treated with ketorolac, while constipation was significantly increased in patients who received morphine only. Drug costs per day were similar in both groups; statistical differences were observed in patients who started on lower morphine doses (<100 mg/daily) in the two groups (4.3 in the ketorolac-morphine group versus 3.4 in the morphine group; P=0.012). The use of NSAIDs reduces the need for an opioid dose escalation or allows the use of lower doses. Their use is associated with a more intense gastric discomfort, but results in less opioid-related constipation. The eventual additive cost for NSAIDs therapy is negligible, especially in patients taking high doses of morphine.