Three modalities for control of cancer pain: efficacy and safety

ABSTRACT

We have studied 60 patients suffering from intractable upper abdominal cancer pain. They were classified into 3 equal groups. Group I [oral morphine] patients were given oral sustained-release morphine tablets [MST] every 12 hours with short-acting morphine tablets as required for breakthrough pain. The dose was adjusted every week to achieve pain relief without maximal recommended dose. Group II [neurolytic celiac plexus block] patients were scheduled for neurolytic celiac plexus block, under X-ray screening, using alcohol 100%. Oral MST was given as a supplement if there was any residual pain after the block. Group III [epidural morphine] patients were scheduled for epidural morphine injection via an epidural catheter, 0.03 - 0.05 mg/kg every 4-6 hours as required. No oral MST supplementation was given. The success of each treatment was evaluated by comparing pre-treatment [baseline] and post-treatment [for 12 weeks] scores pain intensity using visual analogue scale and functional status using Karnofsky performance scale. Opioid consumption per day and side effects of each treatment were recorded. Our results showed that all modalities produced adequate pain relief. There was gradual and significant [p<0.05] increase in the oral morphine dose from the first to last week [from 48 to 227 mg/day] with gradual deterioration in the patient's functional status. Drug-related side effects were nausea, vomiting and constipation. Neurolytic celiac plexus block was associated with a reduction in analgesic drug administration, drug related side effects and insignificant improvement of the functional status of the patients during the first 2 weeks. Complications related to the block were transient diarrhea and hypotension without any neurological complications. With epidural morphine, all patients had adequate pain relief from 11 mg morphine/day, but the daily epidural morphine requirement showed a three fold increase at the 12[th] week [p<0.05]. The functional status of the patients was significantly [p<0.05] high during the first 2 weeks. Pruritus was the main subjective complaint, in addition to the technical complications, such as dislodgment or occlusion of the epidural catheter, or infection. Respiratory depression was not detected in any of our patients. We conclude that no single modality is capable of providing complete relief of intractable upper abdominal cancer pain. Combination therapy should be the rule rather than the exception as each one offers its own advantages and disadvantages