Mechanism-based Choice of Therapy: Can Treatments Success in Fibromyalgia Patients be Coupled to Psychophysical Pain Modulation Profile?

• Status: Unknown status
• Trial end date: 2013-01-01
• Target enrollment: 0
• Participant gender: All

Summary

Hypothesis:

Response to therapy in fibromyalgia can be improved by coupling of specific medications to the individual patterns of dysfunctional pain modulation. Individuals exhibit wide range of pain modulating capabilities that can be assessed by dynamic psychophysical testing. Those that exhibit less efficient endogenous analgesia and/or increased pain summation are known to be more prone to suffer from pain. Tailoring medications to compensate for the specific dysfunctioning modulatory mechanism will improve pain control.

• Phase: N/A
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: Tel-Aviv Sourasky Medical Center
• Collaborators: Rambam Health Care Campus; University of California, Davis
• Treatments: Duloxetine Hydrochloride; Pregabalin

Criteria

Inclusion Criteria:

• Fibromyalgia patients. All patients will undergo physical examination and tender point evaluation to ascertain fulfillment of the ACR 1990 criteria for classification of fibromyalgia (Wolfe et al 1990) i.e. the presence of widespread pain lasting at least 3 months and the presence of tenderness in at least 11 of 18 tender points.

Exclusion Criteria:

• Age below 18 and above 80

• Patients with cognitive dysfunction precluding use of psychophysics, those who cannot communicate in Hebrew, abnormal renal function with creatinine above 1.5, and elevated liver enzymes >x3 upper limit. Since the duloxetine has the potential to act as both substrate and an inhibitor of cytochrome P4502D6 (CYP2D6) inhibiting, caution should be used when other CYP2D6 substrates and inhibitors (some tricyclic antidepressants and SSRIs) are coadministered with duloxetine (Skinner et al., 2003). Patients currently treated with Douloxetine, Pregabalin, Gabapentin, Milnacipran, amitryptiline or other SSRIs, NSRIs or tricyclic medications will not be recruited unless they consent to discontinue prior medications for three weeks before enrolment to the study. During this period the use of NSAIDS and common analgesic medication will be permitted.

• Patients not currently treated with such medications can be recruited.

• Patients suffering from chronic pain due to a known active malignancy or other localized cause (e.g. fracture, Herpes Zoster etc.) will not be recruited.