A Study Testing Topical Pain-Relieving Herbal Plasters in People Who Are Using Opioids for Their Pain

The are doing this study to find out whether using topical (on the skin) herbal plasters, Tibetree pain- relieving plasters (PRPs), can be an effective addition to standard opioid therapy for pain management. The researchers will look at whether the Tibetree PRPs are a practical (feasible) and effective way of managing localized pain (pain that is limited to a certain area) in people who are currently taking opioids. Participants in this study will have cancer or have had it in the past.