Lidocaine Patch for Neck Pain

84 patients will be allocated to receive lidocaine patch or an identical placebo patch for phase I of this crossover study. Depending on the area of pain, up to 3 patches can be applied. Patches will be applied for 12 hours on and 12 hours off (e.g. from 8 PM to 8 AM or 8 AM to 8PM) depending on whether a person's pain is worse in the day or night.

At the end of 4 weeks of treatment, patients will return to clinic for the post-phase I treatment evaluation, at which time outcome measures will be collected. Patients will then enter a 1-week washout period, after which patients will return between 1 and 3 weeks (depending on patients' availability) to receive the treatment patch patients did not receive in phase I (i.e. lidocaine for group II patients and placebo for group I patients). The short washout period is justifiable based on the short half-life of lidocaine (90-120 minutes) and is consistent with previous topical lidocaine crossover studies. The crossover patch will be applied in the same fashion as in the 1st phase, again for a 4-week duration.

In order to reduce confounding variables, subjects in both groups must agree to not seek any additional pain management treatment as long as patients remain in the study. However, some treatments, such as physical therapy or exercise that are widely recommended can continue, so patients will be told to advise patients' pain clinic physician of any new treatments patients wish to seek during this time period. Subjects will be also be advised that patients can be prescribed rescue medications in the form of a non-steroidal anti-inflammatory drug or acetaminophen, or tramadol (up to 100 mg/d) for those who have already failed a non-steroidal anti-inflammatory drug and acetaminophen, or cannot take the drugs for medical reasons (e.g. renal disease, high cardiovascular risk).

The primary outcome measure will be average neck pain over the past week, 4 weeks post-treatment. A positive categorical outcome (i.e. responder) will be defined as a 2-point or greater decrease in average neck pain coupled with a patient global impression of change score </= 3/7.

Inclusion criteria

• Age 18 to 90 years
• Tenderness to palpation over affected areas (using average 4 kg force for 70 kg person)
• Average pain score >/= 4 over the week prior to enrollment
• On stable doses of analgesics for 2 weeks prior to enrollment
• Chronic mechanical neck pain > 3 months in duration
• Boundaries are upper trapezius, mastoid processes, shoulders

Exclusion criteria

• Radicular pain as determined by clinical presentation
• Opioid dose in oral morphine equivalents/day > 30
• Moderate or severe hepatic disease (will obtain blood work and exclude individuals with aspartate aminotransferase (AST) or alanine aminotransferase (ALT) > 3 times the normal range.
• Previous neck surgery
• Known structural defect presumed to be the primary pain generator (e.g. severe degenerative disc or facet joint disease)
• Serious medical (e.g. unstable angina) or psychiatric (e.g. poorly controlled depression, active substance abuse) that could interfere with treatment or pain response
• Secondary gain
• Pregnancy or breastfeeding
• painDETECT score > 18
• Known allergy to lidocaine
• Diffuse pain phenotype (e.g. fibromyalgia)
• Cervical pain greater in area than 3 patches (10 x 14 cm/patch)
• Skin defects (e.g. burns, active infection) in area(s) of application that could result in significant systemic absorption