A Study of Genetic Variation Influencing Pain and Response to Opioid Medications

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.

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.

Inclusion Criteria:

1. Adult patient, aged 18-71
2. Recipient of chronic opioid therapy
3. Patient is able to produce a saliva sample
4. If a past study participant, patient will have agreed to be contacted for future studies.

Exclusion Criteria:

a. not meeting inclusion criteria