Clinical Textbook of Addictive Disorders 3rd ed - R. Frances, S. Miller, A. Mack (Guilford, 2005) WW

380 IV. SPECIAL POPULATIONS1. What is conventional practice for pain of this type?2. Are there other available therapies that might be considered in lieu ofan opioid trial, for which there is a reasonable likelihood of the same orbetter efficacy at no greater risk?3. Is the patient at relatively increased risk of side effects by virtue of medicalcomorbidities or their treatments?4. Is the patient likely to manage opioid therapy responsibly?5. Is a trial of opioid therapy in this patient appropriate given the clinician’sknowledge and skills; if not, could the patient be managed withthe help of a consultant, or should referral be considered?These questions apply to all patients, irrespective of drug use history. Theyimply that there is no population for whom opioids are absolutely contraindicated,but that concerns such as the ability to control drug use are central in thedecision-making process.Principles of Prescribing. Guidelines for the selection and administration ofopioid drugs derive from knowledge of opioid pharmacology and clinical experience(American Pain Society, 2003; Portenoy & Lesage, 1999; World HealthOrganization, 1996) and follow a few key principles.1. Issues in drug selection. Opioids can be classified as pure agonistsand agonist–antagonist drugs (Table 17.5). In contrast to the pure agonists,the agonist–antagonist opioids, including the mixed agonist–antagonists (e.g.,pentazocine, nalbuphine, butorphanol, dezocine) and the partial agonists (e.g.,buprenorphine), are characterized clinically by a ceiling effect for analgesia, thecapacity to precipitate an abstinence syndrome in patients who are physicallydependent on pure agonists, and a lesser degree of “liking” by those with thedisease of addiction (Houde, 1979; Hoskin & Hanks, 1991). Some (pentazocineand butorphanol) have an incidence of psychomimetic effects substantiallygreater than that of the agonist drugs.With the exception of buprenorphine, which now is also used as agonisttherapy for opioid addiction, the agonist–antagonist drugs are not generallyconsidered for chronic pain management. Although these drugs appear to haveless abuse potential than the pure agonists and therefore might be selected forlonger term use in patients with drug abuse histories, no specific data supportthe comparative safety and efficacy of this approach, and most pain specialistsemploy pure agonist drugs even with these patients. Because of the risk of precipitatingan abstinence syndrome, agonist–antagonists should not be administeredto patients who have developed physical dependence to opioids.In the United States, the most common approach to the treatment ofmoderate pain involves the administration of a product combining a nonopioidanalgesic (acetaminophen, aspirin, or ibuprofen) and an opioid (hydrocodone,