Medication Assisted Treatment

The National Institute on Drug Abuse says that naltrexone works by blocking the receptors in the brain that opioids would otherwise bind to and activate, rendering those drugs incapable of eliciting their addictive high. Naltrexone is safest when used after the person has finished medically supervised detox because using it when opioids are still in the body may prompt extremely severe withdrawal symptoms. Naltrexone is viewed to be an ideal drug for treating opioid abuse because of the ease of administration, minimal side effects, and lack of abuse/addiction liability.

While naltrexone works by completely blocking the activation of opioid receptors in the brain, a drug like buprenorphine works by partially activating them. This is why naltrexone is referred to as an opioid antagonist, and buprenorphine is called a partial opioid agonist—meaning that it activates the brain’s opioid receptors but not to the extent that a “full opioid agonist” like heroin does.

Since buprenorphine is only a partial agonist drug, there is a “ceiling” to its opioid effects. It is incapable of eliciting as strong of a high as many full opioid agonist drugs of abuse. According to the Substance Abuse and Mental Health Services Administration, this lowers its potential for misuse, as well as the degree of the withdrawal effects associated with the treatment drug itself. Used this way, buprenorphine can help wean individuals off their dependence on full opioid agonists.

Naltrexone has also shown applicability as a tool to treat alcoholism. An injectable, extended-release form of naltrexone known as Vivitrol has been called “the most important breakthrough in addiction treatment in the past 25 years.” A medical director tells the New York Daily News that while naltrexone requires a pill to be taken once every day or two days, Vivitrol is administered via injection once a month. According to the director, patients find this route of administration helps them remain sober.

On the other end of the spectrum of opioid agonist drugs like methadone and buprenorphine are the opioid antagonists, including naloxone. In addition to blocking the activation of opioid receptors, naloxone acts as a competitive antagonist and can actively reverse the narcotic effects of many full opioid agonist drugs. It is this ability that makes naloxone such a vital medication in treating opioid overdoses and saving lives.

Naloxone’s use extends beyond its role as an “antidote” to opioid overdose. It is often found in a combination formulation with buprenorphine (e.g., as the opioid dependence treatment medication Suboxone—a drug which the Washington Post describes as “the drug [that] could combat the heroin epidemic.”). Its inclusion in such a drug is done to curb abuse of the treatment drug itself. People trying to misuse Suboxone may not only experience blocking of the desired opioid effects but may also experience immediate opioid withdrawal.

Other drugs that are used to help people struggling with alcoholism include disulfiram and acamprosate. When used as prescribed, disulfiram (trade name: Antabuse) will result in a very unpleasant reaction should the individual consume even small amounts of alcohol. It achieves this effect by blocking the activity of a specific enzyme important in metabolizing ethanol. The resultant buildup of a chemical intermediary (acetaldehyde) is what’s behind the adverse physical effects. Reactions can include headache, nausea, vomiting, chest pain, sweating, blurred vision, and breathing difficulty, among others. Experiencing such uncomfortable symptoms and knowing that they will occur is thought to deter individuals from drinking.

Acamprosate (trade name: Campral) is specifically designed to maintain the chemical balances in the brain that are disrupted in a person with pronounced alcohol dependence. It is another drug used to assist in the treatment of alcoholism. Acamprosate may work by protecting the brain from overexcitation that results when a person tries to withdraw from alcohol in the wake of its significant disruption of excitatory and inhibitory signaling. In doing so, relapse likelihood may be decreased and abstinence promoted.

Sometimes, the weapons in the fight against addiction come from unexpected places. In 1998, the U.S. Food and Drug Administration approved modafinil (under the brand name Provigil) as a treatment for narcolepsy.

Modafinil is a non-amphetamine central nervous system stimulant and eugeroic—a drug that promotes alertness/wakefulness. It is prescribed for those who struggle to function in their day-to-day lives because of irregular or diminished sleep patterns. Irregular sleep can be caused by long work shifts, sleep apnea, PTSD, or other reasons.

Modafinil’s effects have also drawn attention for possible use as a treatment for cocaine dependence—a condition for which there is currently no FDA-approved drug. It has been theorized that the stimulant effects of modafinil could help alleviate some of the symptoms of acute cocaine withdrawal.

Furthermore, there is evidence that modafinil may reduce cocaine cravings and mute some of the subjective responses to this addictive drug. When used in combination with individual behavioral therapy, it could prolong abstinence. More research into any direct effects is needed.

Primarily used for depression, seasonal affective disorder, and smoking cessation, bupropion also sees some off-label use in managing attention deficit disorder. It has been investigated for a potential role in different types of addiction treatment.

The Primary Care Companion to the Journal of Clinical Psychiatry published a review article detailing some of ”the many uses of bupropion.” Though reports were mixed and the results far from conclusive, the author cites several studies that may support the use of bupropion to treat specific types of substance abuse. 

For example:

• Bupropion was “helpful” in reducing cravings for cocaine use in one study.
• Sustained-release bupropion (e.g., Wellbutrin SR) combined with participation in a 12-step program may reduce methamphetamine cravings.

As with bupropion, mirtazapine (trade name: Remeron) is mainly used to help patients with depression. There is some data, albeit limited, that mirtazapine in conjunction with therapy may benefit people during alcohol detoxification.

One study suggests that this therapeutic value is achieved by decreasing collateral anxiety, depressive symptoms, and minimization of physical and perceived discomfort in the post-withdrawal period.

Suboxone reduces cravings and helps fool the brain into thinking the illicit drug is still being used. The person taking the medicine feels normal, not high and withdrawal does not occur. This medication can be a pill or a sublingual tablet/film placed under the tongue.

Methadone as a treatment for heroin, oxycodone, or fentanyl dependence. Methadone is cheaper than heroin, oxycodone, or fentanyl and remains active in the body for longer. Its effects last about 24 hours, with the peak effects felt 4 to 8 hours after taking the dose. This extended-release means only a single daily dose is needed.  

Methadone reduces risky behaviors such as injecting and the quest for product that allows someone to remain stable while making further positive changes in their lives. Methadone treatment can be long-term (months or years), to help the person reduce the risks of using illicit drugs, or short-term (two weeks or less), to help the person safely withdraw from heroin, oxycodone, or fentanyl.  

Methadone is taken as a drink.

Other isolated examples of research into additional pharmacotherapeutic agents include:

• Baclofen, a skeletal muscle relaxant used primarily to treat muscle spasticity, has been investigated for its potential role in maintenance treatment for opioid dependence.
• Some research evidence shows that the anticonvulsant medication, gabapentin, may help manage specific withdrawal symptoms in methadone-assisted detox.
• Like gabapentin, the anticonvulsant vigabatrin may reduce some alcohol withdrawal symptoms.
• Low-dose topiramate could warrant attention for a potential role in preventing alcohol relapse. It may help reduce alcohol cravings, anxiety, and depression when used to treat alcohol dependence.

Though in these instances, official approval as addiction treatment medications has not been given, they serve as indicators of how researchers continue to look for new pharmaceutical options to add to the toolbox of addiction treatment.

With ongoing investigation, the hope is that we will soon be able to augment our proven therapeutic methods and practices to make additional headway in substance abuse treatment.