Opioid addiction is very difficult to treat successfully or permanently (Park & Friedmann, 1997). The use of opioid replacement therapy or partial opioid treatment to prevent relapse in persons in treatment for opioid addiction or opioid withdrawal has proven successful in many cases (Vo, Robbins, Westwood, Lezama, & Fishman, 2016). Methadone, buprenorphine, naloxone, naltrexone, and thienorphine are some of the more successful medications which have been shown to help in the process of opioid withdrawal and the prevention of relapse in opioid addiction cases. Some success has been seen in non-drug withdrawal methods, including the use of acupuncture (Wu, Leung, & Yew, 2016).

Opioid Withdrawal
Opioid withdrawal is a lengthy and painful process; the physical withdrawal can last for over a week, while the emotional withdrawal usually lasts for months or even years (Weiss, Potter, Griffin, Provost, Fitzmaurice, McDermott, Srisarajivakul, Dodd, Dreifuss, McHugh, & Carroll, 2015). For this reason, most people addicted to opioids are unable to stop the use of opioids without medical assistance (Weiss et al., 2015).

Medications Used in Opioid Addiction Treatment
There are several medications used in the treatment of opioid addiction. Some mimic the effects of opioids, but are entirely synthetic, while others contain a small component of active opioids combined with non-addictive agents (Yu, Li, Cui, Yan, Yong, Zhou, Su, & Gong, 2014). These are known as partial opioids (Yu et al., 2014).

Methadone
The best-known and most often-used treatment, Methadone maintenance therapy replaced opioids with a synthetic medication which mimics the effects of opioids, thus lessening both withdrawal symptoms and cravings for opioids (Park & Friedman, 1997).

Buprenorphine
Buprenorphine is a mixed partial agonist opioid receptor modulator used in both opioid addiction treatment and pain control in people not addicted to opioids (). When used for pain control, lower doses of the medication are used; when treating addicted persons, higher doses are prescribed. Advantages of buprenorphine over opioids and methadone are that is a partial agonist, which decreases the chance of acute respiratory distress common with the abuse of both opioids and methadone (Binder, Messaadi, Perault-Pochat, Gagey, Brabant, & Ingrand, 2016).

Naloxone
Naloxone works by blocking the effects of opioids, and is generally used in cases of overdose (Kunøe, Lobmaier, Ngo, & Hulse, 2014). Sold under the brand name Narcan, it can also be combined in pill form with small doses of opioids to help prevent the abuse and overdose of opioids in active addicts (Kunøe et al., 2014).

Naltrexone
Similar in chemical makeup to naloxone, naltrexone is also used to reverse the effects of opioids, and thus to prevent death from overdose in opioid and alcohol cases (Sajid, Whiteman, Bell, Greene, Engleman, & Chambers, 2016). Naltrexone can also block the effects of opioids, and is sometimes prescribed to recovering opioid addicts to reduce the chance of relapse; as they will not experience the “high” of opioids while taking naltrexone, they have less incentive to use opioids while on treatment.

Thienorphine
Thienorphine, a partial opioid, has had some success in reducing the cravings for opioids and symptoms of withdrawal in clinical trials (Yu et al., 2014). By supplying the addicted person with a small amount of opioid in the medication, Thienorphine helps the addict to gradually reduce his consumption of the medication without experiencing severe withdrawal symptoms (Yu et al., 2014).

Conclusion
Different medication used for treating opioid addiction work in different ways. Some attempt to replicate the feelings that addicts get from abusing opioids, but in a controlled way, so that the amount of opioid-like medication they need can be reduced gradually over time. Other medications block the “high” that abusers gain from the use of opioids, making them less desirable to the abuser.