Participants in the study must:
1. have acute, non-radicular back strain with onset up to 10 days before the first visit
2. have intact, non-damaged skin at the proposed patch application site
3. be untreated or unresponsive to conservative pain treatment regimens and/or opioids
4. have a minimum pain intensity score of four (4) or more on a scale of 1-10 (a rating
of zero (0) being "no pain" and a rating of ten (10) being "pain as bad as you can
imagine")
5. have a normal neurologic examination
Participants may not be in the study if they:
1. have had surgery or other chronic pain condition within 3 months before first
treatment
2. have back pain radiating below the knee at time of enrollment
3. have neuropathic pain or have been treated with gabapentin or pregabalin for
neuropathy
4. are being treated for or are known to currently have kidney or liver disease
5. have certain other diseases or are using certain types of other drugs.