CYP2D6 Polymorphism, Pain
Conditions
Brief summary
Pain is one of the most burdensome symptoms associated with cancer and its treatment, and opioids are the cornerstone of clinical pain management in cancer patients. Yet, individual patient responses to opioids vary widely, and the patient's genotype contributes to this variability. Specifically, cytochrome P450 2D6 (CYP2D6) genotype has important relevance for response to opioid analgesics that depend on CYP2D6 for bioactivation. Poor metabolizers (PMs) have lower concentrations of active metabolites of codeine (morphine), tramadol (O-desmethyltramadol), oxycodone (oxymorphone), and hydrocodone (hydromorphone), compared to extensive metabolizers (EMs). Morphine and O-desmethyltramadol have 200-fold greater affinity for the µ-opioid receptor than the parent compound, whereas oxymorphone and hydromorphone have 40-fold and 10-fold higher receptor affinity compared to their parent compounds, respectively. Consequently, PMs may fail to derive pain relief from these opioids compared to EMs. Interestingly, the occurrence of side effects may not differ between PMs and EMs so that while PMs may get little to no pain relief from certain opioid analgesics, they may still experience troublesome adverse effects. Intermediate metabolizers (IMs) are also expected to have reduced analgesic response based on their significant reduction in enzyme activity. Conversely, individuals with the UM phenotype may have toxic concentrations of active opioid metabolites, with reports of life-threatening toxicity and death. The µ-opioid receptor gene (OPRM1) is the primary binding site for endogenous opioid peptides and opioid analgesics, and may have additional contributions to opioid response. The investigators propose to examine the effect of CYP2D6 genotype-guided pain management on cancer pain control in study participants and the additional effect of the OPRM1 genotype on response to opioids.
Detailed description
This will be a randomized, open label, multi-site clinical trial conducted in UF Health Cancer Center in Gainesville, FL and in Moffitt Cancer Center in Tampa, FL. Each site will be responsible for overseeing patient care and research at their respective facility. This research will examine pain-related outcomes with CYP2D6-guided cancer pain management for study participants. In addition, the investigators will evaluate a prospective cohort study in the same population examining the effect of OPRM1 genetic variants on pain relief and adverse drug effects over time. Participants will be randomized in a 1:1 manner to receive CYP2D6 genotype-guided (n=50) or non-genotype-guided (traditional, n=50) selection of pain medication. Patients in the genotype arm will be genotyped at baseline for CYP2D6 variants. Participants will fill out the the Brief Pain Inventory-Short Form (BPI-SF) and M.D. Anderson Symptom Inventory (MDASI) questionnaires at baseline. Then, during the clinical visits the same questionnaires will be done during weeks 2, 4, 6, and 8 or by telephone or electronic survey.
Interventions
GENETICCYP2D6
Gentic testing for CYP2D6 metabolic pathway will be performed at baseline.
BEHAVIORALBrief Pain Inventory-Short Form (BPI-SF)
This questionnaire will be completed at baseline and weeks 2, 4, 6 and 8.
BEHAVIORALM.D. Anderson Symptom Inventory (MDASI)
This questionnaire will be completed at baseline and weeks 2, 4, 6 and 8.
GENETICOPRM1
Genetic testing of the OPRM1 will be performed after week 8.
Sponsors
University of Florida
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
SUPPORTIVE_CARE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 120 Years
Healthy volunteers
No
Inclusion criteria
* Diagnosis of histologically or cytologically proven solid tumor with or without metastasis * Receiving treatment at UF Health Cancer Center for outpatient pain management with an opioid
Exclusion criteria
* Undergone surgery within the last three months or are scheduled to undergo surgery during the study period (4 weeks) * Documented psychiatric or neurological condition that would interfere with study participation * Liver transplant * Allergic to opioids
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Brief Pain Inventory-Short Form (BPI-SF) will be used to evaluate pain management and interference between the groups. | Change in baseline, weeks 2, 4, 6 and 8. | Brief Pain Inventory-Short Form (BPI-SF) is a 9 item self-administered questionnaire used to evaluate the severity of a patient's pain and the impact of this pain on the patient's daily functioning. This is a 10-point scale with 0 being the best possible score, meaning no pain, and 10 being the worst possible score, meaning pain as bad as you can imagine. |
| MD Anderson Symptom Inventory (MDASI) will be used to evaluate symptom interference between the groups. | Change in baseline, weeks 2, 4, 6 and 8. | MD Anderson Symptom Inventory (MDASI) modules augment the 19 core MDASI symptom and interference items with additional items identified as unique to a particular patient population. This is a 10-point scale with 0 being the best possible score, meaning did not interfere and 10 being the worst possible score, meaning interfered completely. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Observe Differences in Pain Control and Pain Interference between the number of participants based on OPRM1 Genotype | week 8 | At the end of the study, all participants will be genotyped for OPRM1 and evaluated for pain control (as assessed by the BPI-SF). |
| Observe Differences in Symptom Interference between the number of participants based on OPRM1 Genotype | week 8 | At the end of the study, all participants will be genotyped for OPRM1 and evaluated for symptom interference (as assessed by the MDASI). |
| Observe Differences in Opioid Doses between the number of participants based on OPRM1 Genotype | week 8 | At the end of the study, all participants will be genotyped for OPRM1 and evaluated for opioid dose (as assessed in morphine equivalent doses). |
Countries
United States
Outcome results
None listed