Duloxetine Metabolism and Fibromyalgia
Trial statusRecruiting
Trial phaseNot listed
Trial typeObservational
Biological sexAll
Age18+
SponsorUniversity of Utah
About this trial
People with fibromyalgia report generalized body pain ("pain all over"), increased sensitivity to painful stimulation, chronic tiredness or low energy, sleep problems, and other physical and functional problems. The exact cause of the disorder is poorly understood, and treatment can be difficult.
The degree to which duloxetine is helpful for people with fibromyalgia varies greatly. For some people, it is very helpful for managing fibromyalgia symptoms. For others, people may not notice any benefit. Yet for some, it is a little helpful and the effect is noticeable only when people forget to take the medicine.
The purpose of this study is to collect data to better understand the relationship among gene types that control those enzymes, blood concentrations of duloxetine, and how it helps the symptoms.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Adults 18+
Meeting diagnostic criteria for Fibromyalgia
Patients taking Duloxetine 60 mg/day for at least 8 weeks
Disqualifiers
Pregnant patients per verbal confirmation
Patients that have a history of physician diagnosed kidney or liver disfunction or history of renal dialysis.
Patients requiring an interpreter to communicate
Patient's with progressive illnesses other than fibromyalgia that have a chronic pain and fatigue component (e.g., cancer patients receiving antineoplastic treatment, Parkinson's disease, Multiple Sclerosis).
Trial population
Patients treated at the Pain Management Center (PMC) at the University of Utah who meet inclusion criteria.
Trial design
Design model
Cohort
Time perspective
Prospective
Treatments tested in this trial
Observational
DrugIn a cohort of patients treated with duloxetine for fibromyalgia, participants vitals signs (blood pressure, heart rate, oxygen saturation level, temperature) will be taken as well as height and weight. Participants will fill out a questionnaire regarding their fibromyalgia diagnosis and symptoms. Lastly, participants will complete two sets of blood samples. One blood sample will evaluate genetic variants for duloxetine metabolizing capacity. The other sample will be used to analyze the level of concentration of duloxetine.
Treatment groups
100 Participants
are divided into 1 treatment groupGroup A: Adult patients treated with duloxetine for fibromyalgia1 intervention
Trial outcomes
Primary outcomes
1
Duloxetine concentrations across metabolizer phenotypes, 3 groups
Metabolizer phenotypes will be separated into 3 groups based on diplotypes. Ultrarapid metabolizer phenotypes will be measured by having an activity score of greater than 2.0. Normal/intermediate metabolizer phenotypes will be measured by having an activity score between 1.0 to 2.0. Slow metabolizer phenotypes will be measured by having an activity score between 0.75 to 0.
Time frame
Obtained four hours after morning duloxetine dose.2
Measure inhibitors and inducers of CYP1A2 and CYP2D6 in blood sample
Inhibitors and inducers of CYP1A2 and CYP2D6 are defined by the Drug Interaction Flockhart Table. A strong inhibitor will be measured by ≥ 5-fold increase in plasma AUC or more than 80% decrease in clearance. A moderate inhibitor will be measured by 2 to 5-fold increase in the plasma AUC or 50-80% decrease in clearance.
Time frame
Obtained four hours after the morning duloxetine dose.Secondary outcomes
1
Symptoms of fibromyalgia
Measured by the Revised Fibromyalgia Impact Questionaire (FIQR) and ACR 2016 criteria for fibromyalgia. The FIQR is scored on a scale of 0-100, with higher scores (100) indicating a greater impact of fibromyalgia (worst outcome) and lower scores (0) indicating a lesser impact of fibromyalgia (better outcome).
Time frame
From start of study visit to end (approximately 2 hours).2
Vital signs, heart rate
Heart rate (bpm) will be recorded.
Time frame
One time at the start of the study visit.3
Vital signs, noninvasive blood pressure
Blood pressure (mmHg) readings will be recorded.
Time frame
One time at the start of the study visit.4
Vital signs, oxygen hemoglobin saturation
Oxygen hemoglobin saturation (Sp02 using pulse oximeter) will be recorded.
Time frame
One time at the start of the study visit.Sponsors and contacts
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Source ClinicalTrials.gov