Pain
Conditions
Brief summary
Our goals for this study involve using intravenous lidocaine as it is normally used in the Stanford Pain Management Center to assess the effect of intravenous lidocaine on chronic pain. Studies have been done determining the efficacy of intravenous lidocaine for treating pain but little research has been done to determine the effects of an intravenous lidocaine infusion on the different components of the pain experience. Our study will incorporate pain quality measures both before and during the infusions of lidocaine to determine changes in present pain intensity.
Detailed description
Each patient will receive an intravenous infusion of lidocaine. Drug will be infused using a computer-controlled paradigm. This paradigm allows increasing plasma concentrations in a step-wise manner, keeping the concentration during each infusion step constant. Plasma concentrations will be increased gradually from 0 to 5 ug/ml in a method at the discretion of the medical team. This will be conducted according to standard medical practice for the infusion and the study procedures will not affect the infusion paradigm. Total infusion time is approximately 1-2 hours. During the course of the study, the primary outcome measure was changed from blood oxygenation level dependent (BOLD) signal to pain intensity.
Interventions
Intravenous lidocaine administered up to 5 µg/ml.
Sponsors
Stanford University
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 100 Years
Healthy volunteers
No
Inclusion criteria
- subjects between the ages of 18 and 100 years for clinical component; subjects between the ages of 18 and 70 for the MRI component * meets the study criteria of chronic pain of either peripheral or central origin * male or a non-pregnant, non-lactating female. If females are of reproductive potential (i.e., not surgically sterilized and/or not post menopausal), they must be practicing an accepted method of birth control, agree to a urine pregnancy test at the start of each study session (for patient scheduled through the clinic, this has already been addressed by the recommending physician) * is not currently on a sodium channel blocking agent, anticonvulsant, or tricyclic antidepressant, * must be able to comply with any other study requirements and complete experimental tasks * have no reported substance abuse within the past six months;
Exclusion criteria
- subject is lactating or pregnant; * subject suffers from clinically significant cardiac, pulmonary, renal or liver disease; * subject allergic to lidocaine. * MRI Component: any metal objects (especially surgical clips), devices, or implants or any other MRI contraindication
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Present Pain Intensity | Patients completed the VAS of present pain intensity immediately before and immediately after placebo and during each infusion level | Present pain intensity was measured using the visual analog scale (VAS). This is scored between 0 (no pain) to 10 (worst possible pain). |
Countries
United States
Participant flow
Recruitment details
71 patients were recruited through the Stanford University Pain Management Center.
Pre-assignment details
Individuals were assessed for neuropathic pain prior to enrollment. Those with co-morbid cardiac disease were excluded from the study.
Participants by arm
| Arm | Count |
|---|---|
| Lidocaine Infusion Each participant will receive an intravenous infusion of lidocaine. Plasma concentrations will be increased gradually from 0-5 ug/ml.
Intravenous lidocaine: Intravenous lidocaine administered during fMRI scan at a maximum dose of 3mcg/ml | 71 |
| Total | 71 |
Baseline characteristics
| Characteristic | Lidocaine Infusion |
|---|---|
| Age, Categorical <=18 years | 1 Participants |
| Age, Categorical >=65 years | 10 Participants |
| Age, Categorical Between 18 and 65 years | 60 Participants |
| Age, Continuous | 47 years |
| Region of Enrollment United States | 71 participants |
| Sex: Female, Male Female | 32 Participants |
| Sex: Female, Male Male | 39 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 9 / 71 |
| serious Total, serious adverse events | 0 / 71 |
Outcome results
Primary
Present Pain Intensity
Present pain intensity was measured using the visual analog scale (VAS). This is scored between 0 (no pain) to 10 (worst possible pain).
Time frame: Patients completed the VAS of present pain intensity immediately before and immediately after placebo and during each infusion level
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Baseline | Present Pain Intensity | 6.25 Units on a scale | Standard Error 0.23 |
| Placebo | Present Pain Intensity | 5.64 Units on a scale | Standard Error 0.24 |
| Lidocaine 3 µg/ml | Present Pain Intensity | 4.92 Units on a scale | Standard Error 0.27 |
| Lidocaine 5 µg/ml | Present Pain Intensity | 4.18 Units on a scale | Standard Error 0.28 |