Chronic pain
Conditions
Interventions
Trade Name: Codeine Phosphate
Product Name: Codeine Phosphate
Pharmaceutical Form: Tablet
INN or Proposed INN: codeine phosphate PhEur
C
Sponsors
The Leeds Teaching Hospitals NHS Trust
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: I. Male or female Caucasian subjects, ages between 18-80 years. II. Signed and dated written informed consent. III. Females of childbearing potential must have a negative pregnancy test and be practicing an effective form of contraception. IV. Patients with a chronic pain condition >3 months duration that has been diagnosed by a pain management specialist. V. Patients with moderate to severe chronic pain (defined as a score of 4 (out of 10) or above on worst pain in the last 24 hours (question 3) on the Brief Pain Inventory at screening and daily in the Patient Diary during pre-treatment.) VI. Adequate renal function (serum creatinine females =65 years) yes F.1.3.1 Number of subjects for this age range 100
Exclusion criteria
Exclusion criteria: I. Patients with a known sensitivity to codeine or who have a history of experiencing intolerable opioid analgesic side effects. II. Patients whose pain could be adequately controlled by increasing their dose of weak opioids. III. Patients with a history of recreational drug use within the last 2 years. IV. Patients with a history of alcohol abuse within the last 2 years. V. Female patients who are pregnant, lactating or of child bearing potential who are not taking adequate contraceptive precautions i.e. an oral contraceptive, an approved hormonal implant, an intrauterine device or condoms/diaphragm and spermicide). A woman of childbearing potential is defined as any female who is less than 2 years post-menopausal or has not undergone a hysterectomy or surgical sterilisation, e.g. bilateral tubal ligation, bilateral ovariectomy (oophorectomy). VI. Abnormal serum electrolytes, which in the investigators opinion would exclude the patient from this study VII. Abnormal urine analysis, which in the investigators opinion would exclude the patient from this study VIII. Haemoglobin outside the normal limits and white blood cell count below the lower limit of normal or above 12 x 109/l. IX. Concurrent surgery, radiotherapy, chemotherapy or nerve blocks and those who have received this treatment 4 weeks prior to the study. X. Patients taking drugs known to be inhibitors of the cytochrome P450 isozyme 2D6 (Appendix 17.4). XI. Patients taking medications that would interfere with the urinalysis e.g. morphine, hydromorphone. XII. Patients who have anxiety or the depression of a degree that the investigators judge that participation in the study would be detrimental to their mental health. XIII. Patients who are unable to understand and complete assessment questionnaires in English. XIV. Patients who have been in another clinical study within the last 4 weeks
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Main Objective: • Determine the proportion of chronic pain patients who lack an analgesic response to codeine (i.e. codeine non-responders) • Investigate whether the proportion of codeine non-responders in the chronic pain population is greater than the well known figure of 10% seen in the general population ; Secondary Objective: • Investigate whether codeine non-responsiveness is different in nociceptive, neuropathic and mixed pain states • Correlate genetic testing from mouth swabs for CYP2D6 and urine testing of morphine metabolites as predictors of codeine non-responsiveness • Investigate the pharmacogenetics of codeine phosphate and its implications in clinical practice for chronic pain clinic attendees • Implement a simple screening test to identify codeine non-responders and therefore potentially avoid unnecessary prescription of this drug ;Primary end point(s): The primary endpoint is the pain scores to determine the proportion of patients who are non-responders to codeine. The definition of a non-responder will be a patient who does not display a reduction in pain scores of 30% or more over the course of 5 days (as measured on daily pain rating scale);Timepoint(s) of evaluation of this end point: at the end of the study for each participant | — |
Secondary
| Measure | Time frame |
|---|---|
| Timepoint(s) of evaluation of this end point: at the end of the study for each participant; Secondary end point(s): Secondary end points will be the correlations between: • genotype and clinical response to codeine • urine metabolites and clinical response to codeine, • genotype, and urine metabolites. • m-BPI-sf, SF-8 and Global Impression of Change, and clinical response to codeine and genetic group. | — |
Countries
United Kingdom
Contacts
Public ContactPain Management department
The Leeds Teaching Hospitals NHS Trust
Outcome results
None listed