[Clinical and economical evaluation of new analgesics for the management of chronic pain].

The management of chronic pain still represent a challenge for physicians. Opioids are the main stem in the treatment of chronic severe pain, not only for their potency, but as they act as central drugs. The main limit to their utilization in clinical practice is the prevalence of side effects, in particular in the gastrointestinal tract, whose constipation represents the most common. Two new formulations are nowadays available on the market: tapentadol PR (TAP PR) and oxycodone/naloxone (OXN). A recent meta-analysis showed that both drugs have a better tolerability profile than a tradizional opioid, such as oxycodone CR (OXY CR), but TAP PR reduces by 47% (RR=0.53) the percentage of patients discontinuing treatment because of side effects, compared to 24% (RR=0.76) of OXN. A similar advantage has been reported in the reduction of the risk of developing nausea and/or vomiting: TAP PR reduces the risk by 47% (RR=0.53), while OXN reduces the risk by only by 10% (RR=0.90). Both drugs redu