Assessment of dosing frequency of sustained-release opioid preparations in patients with chronic nonmalignant pain.

Objective: Many patients with moderate to severe chronic nonmalignant pain require dosing of long-acting opioids more frequently than recommended by the product's manufacturer. To accurately quantitate opioid dosing in clinical practice, daily dosing was prospectively assessed in pain clinic patients.

Methods: A single-center, 30-day, prospective, observational cohort study, approved by the hospital IRB. Methods: Forty-one evaluable adult outpatients receiving treatment with long-acting opioids for moderate to severe chronic nonmalignant pain. Methods: The primary measure was the daily number of consumed doses of prescribed long-acting opioid. Rescue medication use, average daily pain intensity, and patient-reported adverse events were also recorded.

Results: The mean daily number of doses was 3.0 for oxycodone controlled release (CR), 2.9 for morphine CR, and 3.7 for methadone. For transdermal fentanyl, 50% of patients required dosing every 24-48 hours. Ninety-one percent of oxycodone CR-treated patients, 86% of morphine CR-treated patients, and 50% of fentanyl patch-treated patients required dosing more frequently than that recommended by the product's manufacturer. Patients who received oxycodone CR, morphine CR, and transdermal fentanyl required a mean of 2.9, 2.9, and 3.7 rescue doses per day, respectively.

Conclusions: Many patients taking common long-acting opioids for chronic nonmalignant pain require dosing more frequently than recommended by product labeling, and take an additional 3-4 daily doses of rescue opioid, yet they continue to report moderate to severe pain. Newer opioid formulations that can provide sustained analgesia with convenient dosing are needed as well as a better understanding of the many additional factors that may influence opioid use patterns in patients with chronic pain.