Pharmacotherapies for Opioid Addiction
Opioids, and painkillers in particular, are widely abused in the United States. Some drugs, like heroin, are illicit substances that have been outlawed and can only be obtained on the black market via drug dealers. Others, like OxyContin, are available via doctor’s prescription and, up until very recently, used to be available at the corner pharmacy (OxyContin robberies have reduced the number of US pharmacies willing to stock the drug).
Although the traditional substance abuse addiction models in the US focus primarily on complete detoxification and abstinence followed by counseling and possibly cognitive-behavioral therapies, opioids are among the hardest substances to kick. Addiction professionals have been forced to admit that initial recovery from opioid addiction requires something more than recovery from, say, alcohol.
The theory behind pharmacological drug addiction therapy is that an addict must be weaned off of a drug very slowly in order to effectuate long-term sobriety. Since heroin is highly addictive, the cravings generated by heroin withdrawal are too strong for most patients to bear. Without additional intervention, these patients quickly abandon their quest for recovery and begin using again. Methadone helps these patients by providing certain pleasant, or at least neutral, physical or psychological effects, while blocking the neuroreceptors responsible for heroin absorption.
Methadone maintenance treatment (MMT) is typically provided in specific locations and settings, such as methadone maintenance clinics or MMT vans. The MMT programs give heroin and opioid addicts long-acting, man-made opioids at levels which prevent the patient from experiencing opioid withdrawal, which in turn reduces cravings, while blocking the more attractive opioid effects such as euphoria.
One of the main arguments against long-term MMT is that it simply transfers addiction from one opioid (heroin) to another (methadone) without addressing the underlying issues or attempting to achieve sobriety. Some would even suggest that these clinics benefit from keeping clients addicted to methadone.
In fairness, most MMT clinics do require participants to undergo more traditional addiction treatment while on methadone. Studies show that the most effective way to get opioid addicts clean is to combine MMT with individual and group counseling, and refer patients to doctors, psychologists and social workers who can help with issues outside the immediate issue of substance abuse.
Research suggests that, compared with patients receiving just MMT, those who undergo more traditional models of treatment in addition to MMT showed significantly greater improvement. The addition of onsite medical and psychological treatment, employment resources and training and family services also helped. It seems, however, that many individuals do not succeed and remain on methadone indefinitely.
Unfortunately, addicts have also figured out how to abuse methadone. Given that methadone is a straight agonist (only positive effects), if taken in high enough quantities it can come close to providing a heroin-like high and can be fatal at overdose.
Given the dubious success of methadone in treating opioid addiction, researchers have developed a new maintenance medication designed to further limit the positive effects of taking the replacement drug and, thus, reduce the risk of abuse and overdose.
Buprenorphine is a partial agonist at the neuroreceptor sites and carries a very low risk of overdose. The drug takes care of withdrawal symptoms associated with heroin dependence without making the patient euphoric or sedated.
In 2000, the US Congress passed a bill (Drug Addiction Treatment Act), which granted certain medical doctors the authority to prescribe particular medications for the treatment of opioid addiction. The passage of the bill shifted control of the opioid addiction treatment market away from the owners of MMT clinics and into the hands of primary care doctors.
Buprenorphine is the very first medication approved by the FDA under the DATA and comes in two forms. Subutex contains only buprenorphine; Suboxone also contains naloxone, which creates significant withdrawal symptoms when addicts inject Suboxone thinking it will make them high.
Doctors who prescribe Suboxone in their offices for detox or maintenance treatment have to be specially vetted by state regulators. They also must be able to adequately counsel patients suffering from drug addiction, or at least be able to identify when referral to an addiction specialist is needed. Unfortunately, not many doctors have embarked on the lengthy training course required to become certified under DATA. Many resist engaging in what will amount to addiction medicine without being qualified to do so.
This shift from the methadone clinic to a medical-office based treatment approach is extremely cost effective for government health programs and opens up treatment to patients who may not have been a candidate for treatment in methadone clinics. For example, some patients may live too far away from an MMT center or have work schedules that prevent them from being able keep appointments at methadone clinics.
Whether a patient is taking methadone or buprenorphine, he or she can function normally if they comply with the prescribed dosing schedules. People undergoing maintenance therapy can work, stay out of jail and reduce risky behaviors like needle sharing. Once stabilized on a particular dose, the patient can then start participating more effectively in counseling and behavior therapy, with an eye toward eventual sobriety and abstinence.
Naltrexone is a long-acting, man-made opioid medication with very few side effects when taken in the absence of other drugs. It completely blocks opioids from reaching their neuroreceptors, which prevents a drug addict from enjoying the positive effects of opioids such as heroin and OxyContin.
Although naltrexone is often used along with buprenorphine in the addiction medication Suboxone, it can also be used on its own. Use of naltrexone can begin during inpatient drug detox, but it is more commonly used on an outpatient basis. Unlike methadone, patients who take naltrexone must be completely detoxified and substance free before starting treatment. Naltrexone is taken by mouth several times a week to block the effects of opioids. As a result, the patient no longer craves the euphoria once associated with heroin-like substances and repeated absence of the positive effects causes the patient to eventually realize that continuing to take the illicit substances would be futile.
Unlike methadone, naltrexone has very little effect on its own and will not be abused or become addictive. Understandably, however, the success of the treatment relies heavily on the patient’s willingness to stick to the prescribed dosage schedule. When a patient becomes non-compliant and stops taking the drug, cravings can quickly reoccur. In order to avoid non-compliance, it is recommended that naltrexone users also participate in counseling and compliance monitoring. Doctors have discovered that only highly motivated and newly detoxed patients who want to be completely drug free, usually due to other factors such as the need to hold down a job or stay out of jail, comply fully with naltrexone dosing regimens.