ABSTRACT
Methadone and buprenorphine are effective maintenance treatments for people who wish to stop opioid use, but do not wish to experience physical withdrawal symptoms. This chapter explores the role of pharmacogenetics on individual responses to drugs, both in terms of therapeutic and adverse effects. The pathogenesis of addiction involves a series of complex interactions among biological factors, environmental factors, psychological factors, and drug use factors. Methadone was proposed as an Opioid Replacement Therapy for heroin dependence in 1965 and is also used as a maintenance treatment for opioid addiction and for pain treatment. The area of pharmacogenetics considers how variations in an individual’s genes impact on their response to drugs, influencing, thereby, how treatments are, or are not, able to affect their changes. The clinical use of pharmacogenetics is not routine but is emerging in some specialist fields, such as cancer and cardiovascular medicine.
