Opioid substitution to improve the effectiveness of chronic noncancer paincontrol: A chart review

We evaluated the efficacy and tolerability of opioids in the long-term mana gement of chronic noncancer pain. This retrospective chart review included 86 outpatients who started receiving, between 1994 and 1998, long-acting op ioids. For each patient, the number of different opioids used and the effic acy and tolerability of each opioid prescribed were noted. During a mean fo llow-up of 8.8 +/- 6.3 mo, the number of opioids used by each patient was 2 .3 +/- 1.4. Patient diagnoses were: back pain (31), neuropathy (20), joint pain (13), visceral pain (7), reflex sympathetic dystrophy (7), headache (5 ), fibromyalgia (3). The first opioid prescribed was effective for 36% of p atients, was stopped because of side effects in 30%, and was stopped for in effectiveness in 34%. Of the remaining patients, the second opioid prescrib ed after the failure of the first was effective in 31%, the third in 40%, t he fourth in 56%, and the fifth in 14%. There was one case of addiction and no case of tolerance. We conclude that if it is necessary to change the op ioid prescription because of intolerable side effects or ineffectiveness, t he cumulative percentage of efficacy increases with each new opioid tested. Failure of one opioid cannot predict the patient's response to another. Im plications: This study showed that if a patient receiving chronic opioid th erapy experiences an intolerable side effect or if the drug is ineffective, changing to a different opioid may result in a lessening or elimination of the side effect and/or improved analgesia.