Duloxetine Metabolism and Fibromyalgia: Observational Study to Understand Treatment Response Variability

What this Trial Is About

Fibromyalgia causes widespread body pain, increased sensitivity to pain, chronic tiredness, sleep problems, and other physical and functional difficulties. Researchers are studying how gene types that affect liver enzymes influence the way duloxetine is processed in the body and how this relates to the treatment of fibromyalgia symptoms. This study aims to better understand why people respond differently to duloxetine and improve personalized treatment plans. Participants in this observational study are adults with fibromyalgia who have been taking duloxetine 60 mg daily for at least 8 weeks. Researchers will collect vital signs, height, weight, and blood samples to measure duloxetine concentration and identify genetic variants of enzymes CYP2D6 and CYP1A2 involved in duloxetine metabolism. They will also assess any medications that may affect these enzymes and contribute to duloxetine’s effects. During the study visit, participants will complete a questionnaire about their fibromyalgia symptoms and provide blood samples four hours after their morning duloxetine dose. Vital signs such as blood pressure, heart rate, oxygen saturation, temperature, and respiratory rate will be recorded. The main outcomes measured include duloxetine levels in the blood based on metabolizer type and the presence of enzyme inhibitors or inducers. The visit lasts about two hours, and findings will help link drug metabolism to symptom changes in fibromyalgia.

Duloxetine Metabolism and Fibromyalgia