IRCT20181113041646N1 IRCT 2019-11-05 Rasht University of Medical Sciences Effect of duloxetine and pregabalin on invalidation in fibromyalgia. Comparison of duloxetine and pregabalin Effects on invalidation score and depression in Patients with Fibromyalgia. 2019-11-21 anticipated 68 Complete https://irct.ir/trial/35203 interventional Randomization: Randomized, Blinding: Not blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment, Randomization description: Randomized allocation with block method by statistical software . 3 Invalidation in patient with fibromyalgia. Intervention 1: Intervention group: Group one includes patients diagnosed with fibromyalgia receiving duloxetine with the initial dose of 30 mg daily in form of oral capsule for one month. The dose will be increased up to 60 mg daily after 1 week depending on tolerance. Duloxetine (Cymbalta (Lilly company – USA) is a serotonine and norepinephrine reuptake inhibitor with formula of C18H19NOS. It can be administered either before or after meals. Intervention 2: Intervention group2: Group two includes patients diagnosed with fibromyalgia receiving Pregabalin capsule orally with the initial dose of 75 mg daily for one month .the dose will be increased up to 150 mg daily after 1week depending on tolerance.. Pregabalin ( Lyrica (Pfizer – USA) )has the formula of C8H17NO2 and its active metabolite is N-methyl pregabalin. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is There is no more information.