November 25, 2013
By Michael Craig Miller M.D.
Harvard Medical School
Opioid drugs such as oxycodone (OxyContin), hydrocodone (Vicodin) and meperidine (Demerol) are among the most powerful painkillers available. Opioids are used both to treat severe acute (short-term) pain as well as various types of chronic (long-lasting) pain.
Doctors agree that prescribing opioids for chronic pain caused by cancer or experienced at the end of life is appropriate and humane. But there is controversy over prescribing these medications for other types of chronic conditions, such as arthritis, migraine or back pain. Opioids target the same brain receptors as heroin, causing euphoria. There is a risk of abusing or becoming dependent on opioids with long-term use.
Painkiller addiction is getting more attention lately. That's because the rate of prescribing opioids for pain has risen rapidly. For example, it nearly doubled between 2000 and 2010. No doubt, much of this prescribing is appropriate. But some public health experts say there's an epidemic of addiction to opioids — a problem that is bigger than cocaine or heroin addiction. And this category of drugs is responsible for more deaths than cocaine and heroin.
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Who Is at Risk?
The risk of developing a painkiller addiction depends on more than just prolonged use of these drugs.
In its clinical guidelines for prescribing opioids, the American Pain Society notes that the most significant risk factor for developing a painkiller addiction is a personal or family history of an alcohol or other substance use disorder. One review of 24 studies found that patients with chronic pain who also had a current or past substance use disorder were about 17 times as likely to develop a painkiller addiction as other chronic pain patients.
Another risk factor is age. Teenagers and young adults are more likely than older adults to abuse or become dependent on opioid painkillers.
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Addiction to opioid painkillers creates long-term changes in the brain. People in treatment for addiction experience debilitating withdrawal symptoms. And they are prone to relapse because of cravings.
Successful treatment has two parts:
- Detoxification -- This usually involves gradually reducing the dose of the drug or temporarily substituting a medication that has less serious withdrawal symptoms.
- Maintenance -- This is a longer (and sometimes indefinite) phase where the treatment focuses on preventing relapse.
Although counseling is an important part of treatment, most people addicted to painkillers require medication treatment during both detoxification and maintenance therapy.
The choice of medications depends on:
- The severity of the painkiller addiction
- A person's motivation to change
The two most commonly used medications during detox and maintenance therapy are methadone and buprenorphine.
Methadone. This drug binds to opioid receptors in the brain. A single dose can ease or prevent opioid withdrawal symptoms and stop cravings for at least 24 hours. Once a patient has gone through detoxification from painkillers, the person can take a daily dose of methadone. This can eliminate the psychological and social problems caused by addiction. And it should keep cravings and withdrawal symptoms at bay.
Methadone itself can be abused at doses higher than those used for detoxification or maintenance. That's why it is available only through specialized clinics. Research suggests that methadone maintenance therapy is especially effective at helping people remain in treatment, perhaps because of ongoing clinical monitoring.
The most common side effects of methadone treatment are slowed breathing and irregular heart rate. Both are most dangerous at the beginning of treatment. For this reason, physical monitoring is necessary and is especially important any time the dose is increased.
Buprenorphine. This medication is less efficient than a medication like methadone. This may sound like a problem, but it is actually an advantage. That is, buprenorphine can relieve withdrawal symptoms while delivering less of a "high." Another advantage is that people are less likely to misuse this drug because increasing the dose typically will not provide more euphoria. It is also harder to take a dangerous overdose of buprenorphine. As a result, people using this medication do not need to make daily visits to a special clinic. Instead, clinicians in private practice can prescribe buprenorphine as long as they have the appropriate license and agree to provide drug counseling (or refer the patient elsewhere to obtain it).
Even so, buprenorphine treatment has several challenges. Some patients use buprenorphine alone to get high. So clinicians usually prescribe it as a single pill that combines buprenorphine with a second drug, naloxone. (The combination pill is called Suboxone).
Naloxone blocks the effects of narcotics. When the patient takes the pill under the tongue as directed, very little naloxone is digested and absorbed into the bloodstream. But if the patient crushes the pill for swallowing or injection, naloxone floods the bloodstream, neutralizing the slight "high" from buprenorphine while causing unpleasant side effects.
Buprenorphine doesn't need daily monitoring like methadone. But given its potential for misuse, researchers are testing time-release versions of buprenorphine, such as an implant or a long-acting depot (injected) formulation.
Naltrexone.This medication is FDA-approved for treating dependency on either alcohol or opioids. Unfortunately, because naltrexone causes unpleasant side effects, most patients eventually stop taking it.
To address this problem, the U.S. Food and Drug Administration approved a sustained-release injectable form of naltrexone for opioid addiction. Although the research suggests this formulation, injected once a month, is more effective than a placebo (inactive form of the drug), it remains unclear how it compares with methadone or buprenorphine.
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Making Treatment Work
Medication alone is often not enough to overcome an addiction to painkillers. Counseling or psychotherapy is a great way to increase the chances of success. This relationship can help a person manage stress, recognize (and avoid) cues in the environment that promote the addiction, and develop a network of supports. It may be important to involve the family in treatment. Addiction support groups are helpful, too.
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Michael Craig Miller, M.D. is the former editor-in-chief of the Harvard Mental Health Letter and an assistant professor of psychiatry at Harvard Medical School. Dr. Miller has an active clinical practice and has been on staff at Beth Israel Deaconess Medical Center for more than 30 years.