An open label study of oral transmucosal fentanyl citrate (OFTC) for the treatment of breakthrough cancer pain

Authors: Fine, PG, Marcus M, De Boer AJ, Van der Oord B
Source:Pain, 45; 149-153, 1991

Background

• The majority of cancer patients experience pain during the course of their disease
• Even when analgesic therapy is initiated, up to 1/3 of patients continue to have moderate to severe pain
• This is usually due to breakthrough pain, which occurs despite baseline narcotic pain medication
• Oral, rectal, or sublingual analgesics used for breakthrough pain have lengthy onset times and erratic absorption characteristics
• OFTC units have been developed that are easy to administer with rapid onset
• This study was designed to test OFTC units in patients with chronic pain from cancer

Materials and Methods

• 10 inpatients with advanced cancer formed the study group
• 9 patients were male, with a study period of 2 days
• All patients had breakthrough pain that was not well controlled on their current therapy
• Doses of OFTC of 10-15 g/kg were used in the patients' episodes of breakthrough pain
• Heart rate, blood pressure, respiratory rate, and oxygen saturation were monitored at 20 minute intervals after OFTC administration
• Patients were instructed to indicate the time they felt the first onset of any analgesic effect
• Measured variables included pain ratings and sense of well-being

Results

• A total of 42 OFTC administrations were given over the 2 day study period
• A mean dose of 12.33 g/kg was used in each OFTC administration
• There were no complications requiring any form of intervention or any interruption of the OFTC use, though respiratory rates and blood pressures were noted to drop within the first 60 minutes of administration
• None of the study patients requested any other type of analgesia for breakthrough pain
• Significant reduction in pain scores were seen at all evaluations from 5 to 120 minutes after administration
• Average time of onset was 9.5 minutes with a range of 5-13 minutes
• Well-being was significantly increased at all of the evaluations

Author's Conclusions

• OFTCs resulted in a consistent and rapid onset of analgesia
• OFTC may be a safe and effective analgesia method for breakthrough pain in cancer patients

Scientific Implications

The vast majority of patients with advanced cancer experience pain as a symptom. Although a baseline level of analgesic medication can be given to reduce this pain, breakthrough pain is still likely to occur. The time to treatment of this pain is extremely important. OFTC has been developed since it has a very rapid onset. This study reports on the efficacy and safety of OFTC in patients with advanced cancer. It was shown that in their patient population, OFTC was efficacious and safe as demonstrated by the fact that no intervention as required for toxicity and no other analgesic medication was required for pain relief. While this is encouraging, it should be pointed out that this study was done in only 10 patients only over 2 days. Also, there was no comparison to other analgesic medication or even placebo. Therefore, the placebo effect cannot be estimated at all. However, in this patient population who may have been selected not to respond to narcotics, (as they were dissatisfied with their current regimen), the onset of analgesia was rapid and seemingly complete. Therefore, in this advanced cancer population where pain relief is a large concern, OFTC may be a very useful medication.