Chronic Low Back Pain | Comparison of the Efficacy of Duloxetine With Placebo in Patients With Chronic Low Back Pain With a Radicular Component

Chronic Low Back Pain research study

What is the primary objective of this study?

Objective: The objective of this study is to compare the efficacy of duloxetine in the treatment of patients with chronic low back pain with a radicular component to placebo. Study hypothesis: Duloxetine is a new substance now in use for the treatment of neuropathic pain. It has proven its efficacy in diabetic peripheral neuropathy and fibromyalgia in several trials. The investigators therefore hypothesize that duloxetine will be efficacious in patients with chronic low back pain and a radicular component. Study Rationale: Chronic low back pain is an extremely common diagnosis. However, therapeutic options for the condition are limited and therapy remains difficult. Duloxetine has proven its efficacy in patients with neuropathic pain and may also be useful in chronic low back pain. If the investigators are able to show a benefit for patients in the duloxetine arm, the substance may constitute a further treatment alternative in chronic low back pain. Study Design: Prospective, randomized, double-blind placebo-controlled cross over study. Patients will be administered duloxetine for 4 weeks followed by a 2 week wash-out phase after which they will be medicated with placebo for 4 weeks. A second group of patients will receive the medication in reversed order. The primary study endpoint is constituted the weekly mean of VAS-Score in the last week of each treatment period. Secondary endpoints are defined as use of rescue medication, Beck Depression Inventory score, Health related Quality of Life SF-36 score and side effects/adverse events.

Who is eligible to participate?

Inclusion Criteria: - Low back pain ( below L1) - Chronic pain, >6 months - Visual Analogue Scale (VAS) ≥ 5 - Back pain with radicular component defined as pain with a burning, tingling sensation within the anatomic distribution of the nerve root and diagnosed by painDETECT questionnaire - Failed back surgery Exclusion Criteria: - Current mood disorder (dysthymia, bipolar mood disorder) - Major Depression > 12 months (Beck Depression Inventory Score ≥ 18) - History of a psychoactive substance use disorder within the preceding 12 months - Major coexisting medical illness (e.g. severe heart failure, pulmonary hypertension, renal insufficiency) - Glaucoma - Acute myocardial infarction - uncontrolled hypertension - Prostate hyperplasia - History of convulsion - Pregnancy; women of childbearing age will be required to use contraceptives during the duration of the study. Furthermore a pregnancy test will be performed prior to the beginning of the study and once a month during the study period. - Participation in a clinical trial in the 3 weeks preceding the study - Allergy to study medication - Use of the following medication: - opioids except for tramadol, - benzodiazepines other than indicated at low doses for sleep disorders - antineuropathic medication including except for that specified in the study protocol - muscle relaxants - antidepressants other than indicated at low doses for sleep disorders - NSAID, Paracetamol - non-selective MAO-Inhibitors - Fluvoxamine, Ciprofloxacin, Enoxacin - Selective Serotonin-reuptake Inhibitors (SSRI) if tapering of these drugs is impossible before inclusion. - Impaired kidney function (Creatinine > 1.5mg/dl) - Impaired hepatic function (GOT, GPT >2 fold standard levels) - Patients who are not able to understand the study measures and are not able to complete pain assessment forms.

Which medical condition, disease, disorder, syndrome, illness, or injury is researched?

Chronic Low Back Pain

Study Interventions

Interventions can include giving participants drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available or noninvasive approaches such as surveys, education, and interviews.

Drug:DuloxetinePatients will receive 120mg of Duloxetine for the duration of 2 weeks after a dosage titration of 2 weeks according to the following scheme: (p=placebo) day: 1 2 3 4 5 6 7: p-30mg p-30mg p-30mg p-30 mg p-30mg p-30mg p-60mg day: 8 9 10 11 12 13 14: p-60 mg p-60 mg p-60mg p-60mg p-60mg p-60mg 60-60mg

Drug:Duloxetine2 weeks of titration of duloxetine to 120mg, (1-0-1), 2 weeks of continuation on 120mg/day.

Study Arms

Research studies and clinical trials typically have two or more research arms. An arm is a group of people who receive the same treatment in the study.

Milk powder pillPatients will receive 2 placebo pills per day for a period of 4 weeks.

DuloxetineIn the experimental arm of the study patients will receive duloxetine, which will be titrated up to a dosage of 120mg over a period of two weeks and continued at this dosage for two weeks.

Study Status


Start Date: May 2010

Completed Date: June 2014

Phase: Phase 4

Type: Interventional


Primary Outcome: Weekly mean pain intensity in study phase I (Visual analogue score, units 1-10)

Secondary Outcome: Use of rescue medication in study phase I

Study sponsors, principal investigator, and references

Principal Investigator: Matthias Oehmke, MD

Lead Sponsor: Medical University of Vienna


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