Clinical trial NCT01166048: Comparison of the Efficacy of Duloxetine With Placebo in Patients With Chronic Low Back Pain With a Radicular Component
Official title: Randomized Double-blind Study Comparing the Efficacy of Duloxetine With Placebo in Patients With Chronic Low Back Pain With a Radicular Component
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Chronic Low Back Pain
Keywords: Chronic Low Back Pain
Radicular component
neuropathic pain
duloxetine
CLBP
Lead sponsor: Medical University of Vienna
Sponsor class: OTHER
First posted: 2010-07-20
Enrollment: 41
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

Brief summary: 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.


Eligibility criteria: 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.

Primary outcomes:
measure: Weekly mean pain intensity in study phase I (Visual analogue score, units 1-10)
timeFrame: Week 4 of study period
measure: Weekly mean pain intensity in study phase II (Visual analogue score, units 1-10)
timeFrame: Week 10 of study period
Secondary outcomes:
measure: Use of rescue medication in study phase I
timeFrame: Use of rescue medication in week 4 of study period
measure: Beck Depression Inventory score in phase I of study period
timeFrame: Beck Depression Inventory score at week 4 of study period
measure: Health related Quality of Life SF-36 score in phase I of study period
timeFrame: Health related Quality of Life SF-36 score at week 4 of study period.
measure: painDetect score in phase I of study period
timeFrame: painDetect score at week 4 of study period.
measure: Use of rescue medication in phase II of study period
timeFrame: Use of rescue medication in week 10 of study period.
measure: Beck Depression Inventory score in phase II of study period
timeFrame: Beck Depression Inventory score at week 10 of study period.
measure: Health related Quality of Life SF-36 score in phase II of study period.
timeFrame: Health related Quality of Life SF-36 score at week 10 of study period.
measure: painDetect score in phase II of study period
timeFrame: painDetect score at week 10 of study period.
Other outcomes:
Locations:
city: Vienna
country: Austria
facility: Department of Special Anesthesia and Pain Therapy, Medical University of Vienna, AKH Vienna
Study officials:
affiliation: Department of Special Anesthesia and Pain Therapy, Medical University of Vienna, AKH Vienna,
name: Matthias Oehmke, MD
role: PRINCIPAL_INVESTIGATOR
References: