A Study of Genetic Variation Influencing Pain and Response to Opioid Medications in Patients With Chronic Pain
The investigators will be collecting saliva DNA samples from chronic back pain patients. The investigators hope to find candidate genes associated with response to opioid medication by correlating molecular genetics data with pain measurement and opioid responsiveness data including opioid hyperalgesia and opioid analgesic tolerance.
|Study Design:||Observational Model: Cohort
Time Perspective: Prospective
|Official Title:||A Study of Genetic Variation Influencing Pain and Response to Opioid Medications in Patients With Chronic Pain|
- Genetic association with various physiologic responses to opioid medication in patients [ Time Frame: Up to 5 years ] [ Designated as safety issue: No ]
Biospecimen Retention: Samples With DNA
Saliva biospecimen collection will be performed via mail or in person. The Principal Investigator will send participants a letter informing them of the opportunity to participate in a study of genetic variation influencing pain and opioid responsiveness phenotypes. If participants agree to provide a saliva biospecimen and to participate in the study of genetic variation influencing pain and opioid responsiveness phenotypes ("the study"), an informed consent letter to participate in the study and an Oragene™ DNA Self-Collection Kit, in disk format OG-250 (DNA Genotek, Inc., Ottowa, Ontario, Canada) will be sent to the participant by the Principal Investigator. According to the manufacturer instructions, participants will provide a 2 ml saliva sample, which will be preserved using the reagents provided within the Oragene kit. Saliva samples are considered stable at room temperature for 5 years by Oragene.
|Study Start Date:||February 2009|
|Estimated Study Completion Date:||December 2012|
|Estimated Primary Completion Date:||December 2012 (Final data collection date for primary outcome measure)|
The investigators hope to find a genetic association with various physiologic responses to opioid medication in patients who suffer from chronic pain (e.g. OIH vs. analgesic tolerance, baseline pain sensitivity, etc.). This has never been done before, and if it proves successful, it could provide physicians a greater understanding of why some chronic opioid users continue needing increased doses of opioids. This data may also help predict which patients will do well with chronic opioid therapy and which ones may not. Initial data with OPRM1 gene analysis in humans already implicates certain SNPs with opioid responsiveness and there have been suggestions for screening patients for OPRM1 prior to initiating opioid therapy in order to optimize their treatment response (Reynolds et al., 2008).
Clin Lab Med. 2008 Dec;28(4):581-98. The value of CYP2D6 and OPRM1 pharmacogenetic testing for opioid therapy. Reynolds KK, Ramey-Hartung B, Jortani SA.
|United States, California|
|Stanford University School of Medicine|
|Stanford, California, United States, 94305|
|Principal Investigator:||Dr Larry Fu-nien Chu||Stanford University|