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

150 III. SUBSTANCES OF ABUSEindividual can be avoided, thus limiting the risk of adverse reactions (Spencer& Gregory, 1989). Hypotension and bradycardia are major side effects ofclonidine, and can be profound. Lethargy is also common, but this effect can beuseful at night.In a hospital setting, clonidine has been used in concert with abstinenceand an opioid antagonist to produce tolerable withdrawal and detoxification ina short period (5–6 days) for persons on methadone doses of 50 mg or less; variousprotocols exist (Charney, Heninger, & Kleber, 1986). This treatment canbe complicated by delirium and/or psychosis (Brewer, Rezae, & Bailey, 1988).The treatment involves sudden cessation of opioid ingestion, precipitation ofan acute abstinence syndrome with an opioid antagonist, and aggressive treatmentof the withdrawal symptoms with large doses of clonidine throughout theday and benzodiazepines at night. Over the 5- to 6-day course, the clonidineand opioid blocker are tapered. Naltrexone with buprenorphine has been usedsuccessfully (Cheskin, Fudala, & Johnson, 1994; Gerra et al., 1995), and thiscombination produces the shortest and least severe withdrawal interval. Benzodiazepinesare not routinely used after the second or third night, and there is arisk of synergistic respiratory suppression in the coadministration of benzodiazepinesand full or partial opiate agonists. A more time-consuming approachwould involve abstinence not precipitated suddenly by an opioid blocker andmore aggressive use of clonidine than would be practical in an outpatient setting.These approaches are appropriate for those individuals who are highlymotivated to become drug-free quickly in a controlled manner, for reasonsrelated to employment or to impending incarceration.It is generally recognized that abrupt withdrawal from opioids is almostalways followed by relapse. The risk of relapse is less with a rational plan fordetoxification, using decreasing amounts of an opioid over time. In this way,the withdrawal syndrome is minimized, rendering the individual more responsiveto other, nonpharmacological therapies during this high-risk phase of treatment.In the United States, the usual first step toward detoxification is toswitch the addicted individual to a longer acting opioid. Methadone is theobvious choice, with a half-life of 15–25 hours in comparison to 2–3 hours formorphine, heroin, and many other commonly available opioids. In additionto methadone, LAAM was approved in 1993 as a maintenance treatmentagent for opioid dependence; however, because of growing awareness of lifethreateningarrhythmias, it is no longer used. Generally speaking, for every 2mg of heroin, 1 mg of methadone may be substituted. The same is true for 4 mgof morphine, 20 mg of meperidine, 50 mg of codeine, and 12 mg of oxycodone.Other equivalencies are available in standard pharmacology texts.Usually, it is not possible to know how much heroin a user is actuallyadministering in a 24-hour period because of the impure nature of the productavailable on the street. Experience shows that an initial dose of 20–30 mg ofmethadone will block most withdrawal symptoms in moderate to heavy users