Methadone Versus Morphine for Moderate to Severe Cancer-Related Pain: A Double-Blind Randomized Parallel Group Study
Treatment of cancer pain is based on the World Health Organization (WHO) step ladder
approach to the use of analgesic drugs. Medication potency increases at each step of the WHO
ladder, from nonopioid (step 1; e.g., aspirin and nonsteroidal anti-inflammatory drugs)
through weak opioids (step 2; e.g. codeine) plus a nonopioid to strong opioids (step 3;
e.g., morphine) plus a nonopioid analgesic. Morphine is considered the gold standard for
the treatment of moderate to severe pain, but this is based on level C criteria. Research
has discovered that methadone is a potent opioid that operates at several levels which are
important for pain control. The primary aim is to compare morphine versus methadone as a
first-line analgesic in patients with moderate to severe cancer pain. Patients will be
randomized to receive either oral slow-release morphine (15 mg) every 8 hours and
immediate-release morphine (10 mg) every 4 hours as needed for breakthrough pain or oral
methadone 2.5 mg every 8 hours and methadone 2.5 mg every 4 hours as needed for breakthrough
pain. Our hypothesis is that methadone will provide equivalent pain control efficacy after
4 weeks of therapy. We postulate that methadone will be as preferable as morphine as an
analgesic. We will compare the two drugs via adverse effects and compare stability of
analgesia via comparison of the number of breakthrough pain episodes. The study will
attempt to establish equivalency of methadone as a first-line analgesic for moderate to
severe cancer pain.
Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Treatment
The Primary Outcome Measure is Whether the Patient Had at Least 33% Reduction From the Baseline Visual Numeric Scale Score for Pain at the Time of the Visit.
Eric E. Prommer, M.D.
United States: Institutional Review Board
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