Pharmacologic Medications for Addictions Treatment: Part II
A. Tom Horvath, Ph.D., ABPP, Kaushik Misra, Ph.D., Amy K. Epner, Ph.D., and Galen Morgan Cooper, Ph.D. , edited by C. E. Zupanick, Psy.D.
3) Provide a substitute for the original substance that is not nearly as enjoyable as the original, but one that prevents highly unpleasant withdrawal symptoms from occurring.
Buprenorphine (Suboxone®, Subutex®) and methadone (Dolophine®, Methadose®, Methadone Diskets®) are substitute medications for opiates (such as heroin or Oxycontin®). Methadone is highly controlled. Only special, licensed methadone clinics dispense methadone. In contrast, Buprenorphine is available from any physician who has taken a one-day course about its use. Most pharmacies dispense Buprenorphine.
In addition to opiate substitutes, there are also substitutes for tobacco use disorders (nicotine addictition). These include gum, patches, lozenges, and sprays. Many nicotine replacements are available without a prescription at pharmacies. Some nicotine replacements require a prescription.
Buprenorphine is partial opiate agonist. A partial opiate agonist is a drug or medication that stimulates activity at opioid receptors in the brain. However, it does not produce as strong an effect as a full opioid agonist (such as morphine, methadone, oxycodone, hydrocodone, heroin, codeine). Like full opioid agonists, this stimulation occurs at receptors. These receptors are normally stimulated by naturally occurring opioids called endorphins. Buprenorphine only weakly stimulates the opioid receptors. It has the effect of reducing withdrawal symptoms, and suppressing cravings. Yet, it does not have the same strong pleasing characteristic of a fast-acting opiate drug.
Buprenorphine has a very long half-life. The half-life of a drug refers to how long it takes the body to breakdown and eliminate a drug. Since it remains in the system longer, it does not need to be taken as frequently. It is beneficial to take a medication less frequently. This reduced frequency helps to break the habit of quicker, more repetitive drug administration common to stronger, but faster-acting opiate drugs of abuse.
Methadone is a full opiate agonist. It mimics opiates such as heroin. It differs from heroin in its pharmacokinetics. Methadone is an oral medication and must pass through the digestive track. This slows its rate of absorption. In addition, it gets to brain much slower but lasts much longer than heroin. Therefore, methadone is useful for preventing withdrawal symptoms. This allows people to taper down gradually, without producing the pleasing and rewarding "high" that is associated with faster acting opiate agonists.
Nicotine replacement therapy (NRT) comes in several forms. Skin patches (Habitrol® and Nicoderm®), gum (Nicorette®), and lozenges (Commit®) deliver controlled doses of nicotine. These delivery methods are available over the counter (OTC), without prescription. The nasal spray and inhaler are available by prescription (Nicotrol®). These products replace nicotine but eliminate the toxins in tobacco products. Many generic products for NRT are also available.
4) Restore healthy neurophysiological functioning so that people do not use addictive substances or activities as a means of self-medication. Correct for neurophysiological damage resulting from chronic drug use, or addictive activities.
Acamprosate: (Camprol®) treats alcohol abuse. It also decreases some of the physical and psychological symptoms associated with alcohol withdrawal. Acamprosate is believed to restore the chemical balance in a brain that became unbalanced by chronic alcohol use. While remaining an FDA-approved medication, recent studies have cast doubt on its effectiveness.
Buproprion (Zyban®, Wellbutrin® Voxra®, and Budeprion®): These drugs target relapse prevention for tobacco withdrawal. Nicotine is the addictive drug in tobacco products like cigarettes, cigars, and chewing tobacco. This medication is in the class of atypical antidepressants. These medications block the reuptake (reabsorption) of the neurotransmitters dopamine and norepinephrine. Reuptake blockers work by allowing neurotransmitters to remain in the synapse for a longer period. This permits them to bind to more receptors. Re-establishing activity in neurotransmitter systems enhances the recovery process.
Varenicline (Chantix®) treats tobacco use disorder (nicotine addiction). Varenicline is a partial agonist of the nicotine receptor. It's unclear exactly how it works. It appears to suppress cravings associated with nicotine use by stimulating the brain's reward system.
Benzodiazepines (e.g. Xanax®, Librium®, Ativan®, Klonopin®, Diazepam/Valium®): These drugs are often called anti-anxiety drugs or anxiolytics. This class of drugs is perhaps the most controversial in addiction treatment. This is because these drugs are frequently abused (see Sedative, Hypnotic, or Anxiolytic Use Disorders).
This class of drugs works by activating the GABA receptors in the brain. These drugs relieve the anxiety associated with withdrawal. They also can compensate for changes that occur in the GABA system following withdrawal from sedative drugs like alcohol or opiates. Furthermore, some people may abuse alcohol or opiates because they are attempting to self-medicate a pre-existing anxiety disorder. Anti-anxiety drugs are useful for treating these underlying disorders. Anxiety is also a symptom of many other types of psychiatric disorders. For these reasons, the cautious and judicious use of Benzodiazepines may be helpful, particularly during the early stages of recovery.
5) Prevent or diminish powerful cravings that cause people to resume drug use or an addictive activity, after a period of cessation.
Naltrexone may be useful for those aiming to moderate alcohol consumption. This is because one of naltrexone's primary functions is to suppress alcohol craving.