Tramadol and acetaminophen combination for chronic non-cancer pain.

INTRODUCTION: There is some evidence to support the use of tramadol in chronic non-cancer pain, especially osteoarthritis pain, but modest analgesic activity is tempered by adverse effects. Combination of a lower dose of tramadol and acetaminophen is postulated to act synergistically, potentially reducing adverse effects without reduction in analgesic efficacy. AREAS COVERED: This review discusses use of tramadol in chronic non-cancer pain and the pharmacokinetics/pharmacodynamics of tramadol and acetaminophen and when combined. Existing published controlled trial data for the effectiveness (efficacy and adverse effects) of tramadol/acetaminophen combination therapy in chronic non-cancer pain is critically appraised. EXPERT OPINION: Combination therapy with tramadol and acetaminophen reduces pain outcomes in several types of chronic non-cancer pains. However, the effect is limited and is based on short duration trials and is associated with a significant adverse effect profile. There are few data comparing other pharmacological options and also sparse evidence to confirm benefits of the putative synergism of tramadol with acetaminophen. Nevertheless, other medications used for these chronic pains also have appreciable side effects and the combination may have a role to play. Increasing incidence of tramadol-associated deaths may lead to legislative changes that could alter prescription trends of tramadol-based medication.