||Methadone is a synthetic opioid analgesic, structurally related to propoxyphene, and used clinically to decrease pain. Methadone is used in opioid withdrawal programs to replace the dependence of heroin, an illegal and short acting drug. It is available in tablet form or as a solution for parenteral injection but it is most commonly prescribed in the form of a liquid mixture to avoid the ‘rush’ felt with intravenous drugs. The side effects associated with methadone use can include physiological dependance, sedation, respiratory depression an effects on the heart and on muscle. In cases of overdose this can cause stupor, hypertension, coma and circulatory collapse(14, 15).
||14. Schuckit, MD. Drug and Alcohol Abuse: A Clinical Guide to Diagnosis and Treatment, fifth edition, Kluwer Academic/Plenum Publishers, New York, Boston, Dordrecht, London, Moscow, p11, 149, 162-163, 165, 327-329. 15. Wild D. (ed), The Immunoassay Handbook, second edition, Nature Publishing Group, London, Basingstoke, New York, 2001, 808-810.