Opioid and Cannabinoid Pharmacokinetic Interactions
We are conducting a study to assess whether smoking marijuana affects the safety of prescribed opioids in patients treated for cancer-related pain. This study will assess whether smoking cannabis affects the absorption, distribution, metabolism and excretion of widely used opioid analgesics. We propose to do this by investigating the effects of smoked cannabis in subjects prescribed morphine or oxycodone for cancer-related pain. We will also assess the clinical safety of cannabinoids and these opioids by monitoring the short-term side effects associated with combined therapy.
|Study Design:||Allocation: Non-Randomized
Endpoint Classification: Pharmacokinetics Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Opioid and Cannabinoid Pharmacokinetic Interactions: A Pilot Study|
- To determine the effects of smoking cannabis on the disposition kinetics of morphine [ Time Frame: Day 1, Day 5 ] [ Designated as safety issue: Yes ]Pharmacokinetics are measured on Day 1, prior to cannabis use, and again on Day 5, following cannabis use on Days 2, 3, and 4.
- To determine the effects of smoking cannabis on the disposition kinetics of oxycodone [ Time Frame: Day 1, Day 5 ] [ Designated as safety issue: Yes ]Pharmacokinetics are measured on Day 1, prior to cannabis use, and again on Day 5, following cannabis use on Days 2, 3, and 4.
|Study Start Date:||May 2006|
|Study Completion Date:||March 2009|
|Primary Completion Date:||March 2009 (Final data collection date for primary outcome measure)|
Chronic pain conditions remain problematic, especially in patients with cancer. Although opioids are effective analgesics, dose-limiting side effects in the form of sedation, nausea and vomiting, and fear of dependence often limit their use at higher - and possibly more effective - doses. Of particular interest, however, is the potential for greater than additive analgesic effect of cannabinoids and opioids in combination that would allow for opioid analgesic effect to be achieved at lower dosages than are necessary alone, which could overcome problems with both tolerance and side effects for both drug classes. Unfortunately, safety data on the combination in humans does not exist at this time and needs to be obtained. As increasing numbers of patients with cancer may turn to cannabis to augment the effects of their opioid analgesics, data on potential pharmacokinetic interactions and clinical safety of the combinations should be evaluated in a controlled clinical research setting.
|United States, California|
|San Francisco, California, United States, 94110|
|Principal Investigator:||Donald I Abrams, M.D.||University of California, San Francisco|