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Assessment of Morphine-induced Hyperalgesia and Analgesic Tolerance in Mice Using Thermal and Mechanical Nociceptive Modalities
Published on: July 29, 2014
Morphine bioavailability from a topical gel formulation in volunteers
Judith A Paice1, Jamie H Von Roenn, J Craig Hudgins
1Department of Medicine, Division of Hematology-Oncology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
Journal of Pain and Symptom Management
|January 8, 2008
Summary
Topical morphine in a pluronic lecithin organogel (PLO) base showed very low bioavailability in humans. This suggests topical morphine is unlikely to effectively manage cancer-related pain when oral administration is not possible.
Area of Science:
- Pharmacology
- Drug Delivery
- Pain Management
Background:
- Oral analgesics are common for cancer pain, but not suitable for all patients.
- Topical drug delivery offers an alternative route for pain management.
- Human bioavailability of topical morphine has not been previously studied.
Purpose of the Study:
- To determine the bioavailability of topical morphine in humans.
- To assess the potential of topical morphine for cancer-related pain relief.
Main Methods:
- A randomized, placebo-controlled, double-blind, crossover study was performed.
- Five healthy volunteers received topical morphine in pluronic lecithin organogel (PLO) or subcutaneous morphine.
- Blood samples were collected over 10 hours for morphine concentration analysis.
Main Results:
- Morphine was rarely detected in plasma after topical application.
- When detected, plasma morphine concentrations were unquantifiable.
- Topical morphine in PLO gel demonstrated very low, unquantifiable bioavailability.
Conclusions:
- Topical morphine compounded in a PLO base has poor transdermal absorption in humans.
- This formulation is unlikely to be effective for managing cancer-related pain.
- Alternative topical analgesic strategies may be needed.
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