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Try out PMC Labs and tell us what you think. Learn More. Opiate dependence is a major public health problem associated with the transmission of deadly diseases human immunodeficiency virus [HIV], hepatitiscriminal activity, accidental overdose, hospital admissions, and death. The treatment of opiate dependence is controversial, and in most patients, a lifelong duration is probably required. In the United States, methadone may be prescribed by physicians and dispensed by community pharmacies for analgesia as a Schedule II drug under the regulations of the Controlled Substances Act.
However, when used for the treatment of opiate dependence, methadone's accessibility is restricted to practitioners, clinics, and pharmacies d by the Food and Drug Administration for this purpose. Methadone is a synthetic, long-acting opioid with pharmacologic actions qualitatively similar to morphine and is active by oral and parenteral routes of administration. Patients develop tolerance and physical dependence following repeated use. The tolerance may be only partial for most of the pharmacologic effects. An abstinence syndrome consisting of lacrimation, rhinorrhea, sneezing, gooseflesh, nausea, vomiting, fever, chills, tremor, and tachycardia occurs on abrupt discontinuation of the opiate or the administration of an antagonist such as naloxone hydrochloride.
There is cross-tolerance and cross-dependence among the various opiates. This is the premise for using methadone in the detoxification and maintenance of heroin people addicted to heroin. Due to the long half-life and duration of action of methadone, the abstinence syndrome is delayed and prolonged but less severe than that from a shorter-acting opiate such as heroin. Maintenance therapy is the long-term administration of methadone hydrochloride Use of methadone for addiction patients who are dependent on opiates.
The aim is to substitute methadone, a legal, oral opiate with a long half-life, for the illicit, parenterally administered heroin, which is associated with a high risk of morbidity and mortality. Methadone maintenance therapy offers a reprieve from the daily life associated with the procurement and use of heroin and allows a person to reintegrate as a functional member of society.
Methadone therapy achieves this by preventing opiate withdrawal symptoms, blocking the euphoric effects of heroin, and minimizing the craving for heroin. Methadone maintenance has been shown to reduce illicit heroin use, 4 decrease the incidence of infectious disease such as HIV and hepatitis commonly contracted through needle sharing, 5 reduce criminal activity, 6 improve social outcome, 7 and reduce mortality.
A dose of 5 mg of parenteral heroin is approximately equivalent to 20 mg of oral methadone. The dosage of methadone in maintenance therapy remains controversial. It is usually started at 10 to 20 mg and increased in mg increments until the withdrawal symptoms are controlled. Most patients can be maintained at 40 mg a day to control withdrawal symptoms but not eliminate drug craving. Evidence supports the need to administer higher doses of methadone for effectiveness.
However, because a major concern is the high risk of HIV conversion among persons using the intravenous drug-using population, methadone's effectiveness is more accurately measured by the incidence of illicit intravenous heroin use. Strain and coworkers showed that patients given methadone doses of 80 to mg a day versus 40 to 50 mg a day had a much lower incidence of surreptitious, illicit heroin use during maintenance therapy.
Methadone detoxification involves the short-term administration of methadone hydrochloride to blunt the abstinence symptoms of patients who are dependent on opiates and then tapering the dose of methadone with the goal of achieving a drug-free Use of methadone for addiction. The major disadvantage of detoxification in these patients is the high recidivism rate of heroin misuse after completing detoxification.
For detoxification, treatment doses are usually started at 10 to 20 mg and increased in mg increments until the withdrawal symptoms are controlled. A dosage of 40 mg a day controls the withdrawal symptoms for most patients but does not eliminate heroin craving. Once the dose required is established to eliminate withdrawal symptoms, the patient is stabilized on this dose for 2 to 3 days. Then the dose is reduced daily or every other day. If patients are experiencing abstinence symptoms or have a high risk of relapsing into heroin misuse, the practitioner should consider increasing the dose and slowing the tapering schedule.
Individual tapering schedules may vary from weeks to months. Methadone is a good therapeutic alternative to morphine sulfate and other opiate analgesics in the treatment of severe, chronic pain. Morphine and methadone are both effective analgesic agents. In patients treated with opiates for chronic pain, the equivalent analgesic doses for morphine and methadone do not always follow a linear relation, so caution should be taken when switching a patient from morphine to methadone.
Parenteral methadone is about twice as potent as oral methadone. The normal adult dosage of methadone is 2. The dose should be adjusted to the individual needs of the patient. Although methadone has a long half-life, analgesia is not related to the serum half-life, and frequent daily dosing intervals are usually required for pain relief.
Adjunctive analgesics should be considered during the first few days of the initiation of the methadone regimen. Methadone is a good alternative for patients who are being given maximum doses of morphine. However, determining the proper methadone dose based on a patient's current morphine requirement may Use of methadone for addiction challenging. The relative equivalent analgesic dose of morphine to methadone has varied from to 14 mg of morphine to 1 mg of methadone.
Methadone crosses the placenta and can cause fetal dependence. Opiate detoxification during pregnancy is not recommended because fetal distress has been documented during maternal withdrawal from opiates. Lower concentrations of methadone in the plasma and increased methadone clearances have been reported during pregnancy, likely due to increased metabolism.
Dosage should be tailored to the individual during pregnancy to minimize the chance to relapse to heroin use and prevent withdrawal symptoms. Neonates born to women who are dependent on methadone are at risk of developing an opiate abstinence syndrome, but the syndrome tends to develop more slowly, is more moderate in severity, and lasts longer than in infants born to heroin-dependent women.
The interaction of other drugs with methadone may be classified as either pharmacodynamic having effects on the mechanism of action or pharmacokinetic having effects on absorption, distribution, and elimination. The table provides examples of drug interactions with methadone.
Although methadone's long duration of action may be advantageous from a therapeutic perspective, it is a risk factor for overdose. In addition, methadone has a prolonged interval of toxicity that may extend to several hours or days, and it is, therefore, important to observe patients for about 48 hours after a methadone overdose. Another important risk factor includes extremes of age infants and elderly patients because of differences in the pharmacokinetics and pharmacodynamics of methadone in these patients. For example, one mg tablet a therapeutic adult dose has killed33 and 30 mg administered intravenously caused respiratory depression for several days in an 81 year old.
This effect may for the deaths in patients that occurred when methadone was initiated at high doses in methadone maintenance programs. Naloxone, an opiate antagonist, can reverse methadone's toxic effects in patients with overdose. Noncardiogenic pulmonary edema has resulted from therapeutic doses. Methadone is Use of methadone for addiction long-acting opiate used in the treatment of opiate dependence and detoxification and for patients having chronic, severe pain. There is increasing evidence that long-term methadone use in patients who are dependent on opiates has substantial societal benefits, including diminishing illicit opiate use, reducing the transmission of HIV and hepatitis, and decreasing criminal activity and healthcare costs in this population.
These include restrictive governmental regulations, the stigma of opiate addiction, and the lack of healthcare practitioners and clinics sanctioned by Food and Drug Administration that are capable of providing therapy to all patients who may benefit. National Center for Biotechnology InformationU. Journal List West J Med v. West J Med. Author information Copyright and information Disclaimer.
Correspondence to: Dr Anderson, ude. This article has been cited by other articles in PMC. Detoxification Methadone detoxification involves the short-term administration of methadone hydrochloride to blunt the abstinence symptoms of patients who are dependent on opiates and then tapering the dose of methadone with the goal of achieving a drug-free state.
Pain Methadone is a good therapeutic alternative to morphine sulfate and other opiate analgesics in the treatment of severe, chronic pain. Monitor for euthyroid state with free T 3 and T 4 and TSH levels Opiate analgesics Pharmacodynamic cross-tolerance between opioid agents Partial tolerance to analgesic effect of opioids Titrate and adjust dosage interval to attain analgesia, avoid mixed agonist-antagonists eg. Open in a separate window. Figure 1. Waiting in line for methadone at San Francisco General Hospital. References 1. Goldstein A, Herrera J.
Heroin addicts and methadone treatment in Albuquerque: a year follow-up. Drug Alcohol Depend ; 40 Reisine T, Pasternak G. Opioid analgesics and antagonists. Beaumont A, Hughes J. Biology of opioid peptides. Annu Rev Pharmacol Toxicol ; 19 Marsch LA. The efficacy of methadone maintenance interventions in reducing illicit opiate use, HIV risk behavior, and criminality: a meta-analysis.
Addiction ; 93 Human immunodeficiency virus seroconversion among intravenous drug users in- and out-of-treatment: an month prospective follow-up.Use of methadone for addiction
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