Sub-acute Back Pain | Effect of L-dopa In Subacute Back Pain Population

Sub-acute Back Pain research study

What is the primary objective of this study?

This study aims to determine if early treatment with Carbidopa/Levodopa and Naproxen in individuals with sub-acute back pain (SBP) is associated with changes in blocking transition to chronic back pain (CBP).

Who is eligible to participate?

Inclusion Criteria: - Male or female, over the age of 18 years, (no racial/ethnic restrictions) - Must have a history of low back pain for a minimum of 4 weeks and a maximum of 12 weeks with signs and symptoms of radiculopathy: positive straight leg raising test with dermatomal radiation and/or myotomal weakness and/or reflex asymmetry; pain must radiate into buttock or below - Must have a high risk phenotype for chronification of back pain (evaluated at baseline T1-MRI, DTI-MRI, and fMRI scans) - Must have an average pain score over a 5 day period (average of ~15 measures on smartphone app) immediately preceding the baseline visit of ≥ 5 (on a 0-10 NRS) at the baseline visit - Must be willing to read and able to understand instructions as well as PROs - Must be in generally stable health Must sign an informed consent document after complete explanation of the study documenting that they understand the purpose of the study, procedures to be undertaken, possible benefits, potential risks, and are willing to participate Exclusion Criteria: - Previous (distinct) episodes of back pain onset (more than 3 distinct episodes of back pain lasting for a total of more than 4 weeks) in the previous year - Evidence of rheumatoid arthritis, ankylosing spondylitis, acute vertebral fractures, chronic spinal stenosis, prior back surgery and history of tumor of the spine - Low back pain associated with any systemic signs or symptoms, e.g., fever, chills - Other comorbid chronic pain conditions such as fibromyalgia or neuropathic pain secondary to diabetes or post-herpes zoster - Chronic neurologic conditions, including Parkinson's disease, Alzheimer's disease, and other conditions associated with dementia - Significant other medical disease such as congestive heart failure, coronary or peripheral vascular disease, chronic obstructive lung disease, or malignancy - Diabetes Type I or Type II - History of glaucoma or narrow angle glaucoma - Presence of undiagnosed skin lesions or history of melanoma - Presence of severe cardiovascular or pulmonary disease, bronchial asthma, renal, hepatic or endocrine disease - History of myocardial infarction with residual cardiac arrhythmia - History of gastrointestinal bleeding or peptic ulcer - Diagnosis of current depression (assessed via BDI, total > 28 are excluded) or psychiatric disorder requiring treatment, or such a diagnosis in the previous 6 months - Use of therapeutic doses of antidepressant medications (i.e., tricyclic antidepressants, SSRIs, SNRIs; low doses used only in the evening for sleep will be allowed if dose is not changed) - Current use of recreational drugs or recent history of alcohol abuse (pattern of drinking having social, financial or physical consequences) or drug abuse - Any change in medication for back pain in the last 30 days - High dose opioid prophylaxis, defined as > 50mg morphine equivalent/day - Use of MAOIs, currently or within the past 2 weeks - Prior use of Levodopa - Use of any of the following drugs: bromocryptine, linezolid, metoclopramide, phenothiazines,promethazine/codeine, isoniazid, rifampin, pyrazinamide - Oral iron supplementation - Contraindications to use of study product, based on any of the following: - Hypersensitivity to Carbidopa/Levodopa or other constituents of the Carbidopa/Levodopa capsules - Hypersensitivity to lactose or other constituents of the placebo capsules - Hypersensitivity to Naproxen or other constituents of the Naproxen capsules - Hypersensitivity to Acetaminophen or other constituents of the Acetaminophen tablets - Currently taking Levodopa or dopaminergic drugs - Involvement in litigation regarding their back pain or having a disability claim or receiving workman's compensation or seeking either as a result of their low back pain - In the judgment of the investigator, unable or unwilling to follow protocol and instructions - Intra-axial implants (e.g. spinal cord stimulators or pumps) - All exclusion criteria for MR safety: any metallic implants, pacemaker, brain or skull abnormalities, tattoos on large body parts, and claustrophobia - Pregnancy or inability to use an effective method of birth control in sexually active men and women while taking the study drug and for one week thereafter. Barrier contraceptives (condoms or diaphragm) with spermicide, intrauterine devices (IUD's), hormonal contraceptives, oral contraceptive pills, surgical sterilization, and complete abstinence are examples of effective methods of contraception. - Following laboratory abnormalities: liver function tests (SGOT/SGPT) greater than twice the upper limit of normal; unexplained anemia (Hgb <9 g/dL); evidence of renal insufficiency (creatinine >upper limit of normal) or any other abnormality that the principal investigator feels puts the subject at risk during the study - History of chronic opioid use for pain management. - Any medical condition that in the investigator's judgment may prevent the individual from completing the study or put the individual at undue risk

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

Sub-acute 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:NaproxenTake one 250mg naproxen tablet three times a day for 12 weeks.

Drug:Carbidopa/Levodopa12.5mg/50mg Carbidopa/Levodopa, administered orally as capsules, will be titrated up to TID over one week and then continued at that level for 4 weeks. If at the end of this initial 4 week period the participant has "responded," the subject will be maintained on that dose for the duration of the treatment period (12 weeks total). If there has not been a response, the dose will be increased to 25mg/100mg Carbidopa/Levodopa TID for the following 4 weeks at which time the pain status will be re-evaluated. If a response has occurred, that dose will be maintained in a blinded manner for the following 4 weeks of treatment; if not, further dose-titration will occur to 50mg/200mg Carbidopa/Levodopa TID for the final 4 weeks. If a subject experiences an AE at higher doses, then the subject will be given the next lower dose that s/he was able to tolerate and then be maintained on that dose for the remainder of the 12 week dosing period.

Drug:PlaceboTake two placebo capsules three times a day for 12 weeks.

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.

ObservationIndividuals identified as having a recovering phenotype (SBPp) will be assigned to the observational arm and will be asked to continue his/her normal regime and return for the week 12 and week 24 visits for follow-up.

Individuals identified as having a persisting phenotype (SBPr) will be treated with Carbidopa/Levodopa on a flexible dose-titration designed intervention based on dose-response TID throughout the 12 week treatment period. Naproxen (250mg) capsules will be administered orally, one capsule TID, throughout the 12 week treatment period.

Individuals identified as having a persisting phenotype (SBPr) will be treated with placebo capsule plus 250mg naproxen tablet three times a day for 12 weeks.

Study Status


Start Date: February 24, 2015

Completed Date: September 25, 2017

Phase: Phase 4

Type: Interventional


Primary Outcome: NRS pain scale

Secondary Outcome:

Study sponsors, principal investigator, and references

Principal Investigator: Apkar Apkarian, PhD

Lead Sponsor: Northwestern University

Collaborator: National Institutes of Health (NIH)

More information:

Discuss Naproxen