I need to know on a medicine (injection) similar to TRAMADOL, also derived of the OPIUM that has less collateral effects than TRAMADOL. My doctor neurologist indicated me (I don't know the term in English for the doctors' revenue) an injection of TRAMADOL 100 mg a day, because I feel constant supra-pelvic pains. I made many exams, but they don't get to discover what is happening. I already asked for information for the neurologist, but I don't know because he refuses to say. If this medicine has less collateral effects, because you don't use in the place of TRAMADOL?

Thank you