Duloxetine Metabolism and Fibromyalgia

Study Purpose

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.

Recruitment Criteria

Accepts Healthy Volunteers Healthy volunteers are participants who do not have a disease or condition, or related conditions or symptoms	No
Study Type An interventional clinical study is where participants are assigned to receive one or more interventions (or no intervention) so that researchers can evaluate the effects of the interventions on biomedical or health-related outcomes. An observational clinical study is where participants identified as belonging to study groups are assessed for biomedical or health outcomes. Searching Both is inclusive of interventional and observational studies.	Observational [Patient Registry]
Eligible Ages	18 Years and Over
Gender	All

More Inclusion & Exclusion Criteria

Inclusion Criteria:

- Adults 18+ - Meeting diagnostic criteria for Fibromyalgia.

- Patients taking Duloxetine 60 mg/day for at least 8 weeks.

Exclusion Criteria:

- 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 Details

Trial ID: This trial id was obtained from ClinicalTrials.gov, a service of the U.S. National Institutes of Health, providing information on publicly and privately supported clinical studies of human participants with locations in all 50 States and in 196 countries.	NCT06866444
Phase Phase 1: Studies that emphasize safety and how the drug is metabolized and excreted in humans. Phase 2: Studies that gather preliminary data on effectiveness (whether the drug works in people who have a certain disease or condition) and additional safety data. Phase 3: Studies that gather more information about safety and effectiveness by studying different populations and different dosages and by using the drug in combination with other drugs. Phase 4: Studies occurring after FDA has approved a drug for marketing, efficacy, or optimal use.
Lead Sponsor The sponsor is the organization or person who oversees the clinical study and is responsible for analyzing the study data.	University of Utah
Principal Investigator The person who is responsible for the scientific and technical direction of the entire clinical study.	Ken B Johnson, MD
Principal Investigator Affiliation	University of Utah
Agency Class Category of organization(s) involved as sponsor (and collaborator) supporting the trial.	Other
Overall Status	Not yet recruiting
Countries	United States
Conditions The disease, disorder, syndrome, illness, or injury that is being studied.	Fibromyalgia, Duloxetine

Additional Details

Study Purpose: To study the variability of response in patients with fibromyalgia to treatment with duloxetine.Duloxetine is a common FDA-approved pharmacotherapy for fibromyalgia. However, there is significant treatment response variability. Prior work has explored the role of liver drug-metabolizing enzymes CYP2D6 and CYP1A2 in the biotransformation of duloxetine. The genes coding for these enzymes have many variants; some variants are rapid metabolizers, whereas others are slow metabolizers of duloxetine. The different variants may contribute to the wide range of treatment responses to duloxetine among fibromyalgia patients. Supporting duloxetine metabolism as a contributor to drug response variability, researchers have measured plasma duloxetine concentrations following recommended dosing regimens and found concentrations to have substantial variability. A strong correlation between an ultra-rapid duloxetine metabolizer with a poor response to duloxetine will provide useful information when formulating a treatment plan. Patients with a poor response to duloxetine phenotype may be better served by another serotonin norepinephrine reuptake inhibitor such as milnacipran. Early identification of those who would benefit from duloxetine will help a personalized approach to treating fibromyalgia and optimize the cost-effectiveness of pharmacological interventions. Drug interactions with duloxetine that influence drug effect: An important consideration in characterizing duloxetine metabolism is to account for drug interactions that may inhibit or induce CYP1A2 or CYP2D6. The main objective of this proposal is to conduct a feasibility study/pilot study to serve as the basis for a larger study where we refine our study methodology. In a cohort of patients treated with duloxetine for fibromyalgia, this study will measure: (i) Symptoms of fibromyalgia using a validated questionnaire. (ii) Duloxetine plasma concentrations. (iii) Genotype CYP2D6 and CYP1A2 and correlate their plasma concentrations and genotype (rapid, normal, or slow metabolizer) with fibromyalgia symptoms. Hypotheses: (i) Patients with rapid or slow metabolizing variants will have low and high duloxetine plasma concentrations respectively. (ii) Patients with rapid metabolizing variants will have ineffective treatment with duloxetine and patients with slow metabolizing variants will have signs and symptoms of effective treatment or duloxetine toxicity. (iii) Patients who consume inducers or inhibitors of CYP2D6 or CYP1A2 will have low and high duloxetine plasma concentrations, respectively. Patients who consume inducers of CYP2D6 or CYP1A2 will have ineffective treatment with duloxetine, and patients that consume inhibitors of CYP2D6 or CYP1A2 will have signs and symptoms of effective treatment or duloxetine toxicity.

Arms & Interventions

Arms

: Adult patients treated with duloxetine for fibromyalgia

Adults 18+ Meeting diagnostic criteria for Fibromyalgia Patients taking Duloxetine 60 mg/day for at least 8 weeks

Interventions

Drug: - Observational

In 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.

Contact a Trial Team

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Salt Lake City, Utah

Status

Address

Pain Management Center and Pain Research Center at the University of Utah

Salt Lake City, Utah, 84132

Site Contact

Ken B Johnson, MD

[email protected]

801-205-1039

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