People affected by opioid addiction sometimes receive one of two opioid-based medications, called methadone and buprenorphine, as part of their treatment. Current evidence indicates that significant numbers of people who abuse these medications also get involved in the abuse of common prescription substances called benzodiazepines. In a study published in May 2014 in the journal Drug and Alcohol Dependence, researchers from several U.S. institutions compared the seriousness of the health outcomes of methadone-benzodiazepine abusers to the health outcomes of buprenorphine-benzodiazepine abusers. These researchers found that, while both groups of abusers are significantly negatively impacted, methadone-benzodiazepine abuse comes with a substantially higher health risk. Although they\u2019re opioid substances, methadone and buprenorphine act more slowly and have a lower peak effect than heroin and other powerful, frequently abused opioid substances. Taking these properties into account, doctors can prescribe either of the two medications to people in opioid addiction recovery in order to break the cycle of uncontrolled opioid use while simultaneously minimizing risks for the appearance of serious opioid withdrawal symptoms. However, since they do have a narcotic effect, both methadone and buprenorphine may be targeted for abuse by people participating in addiction treatment or by other drug users. Buprenorphine is weaker than methadone and also commonly comes in products that contain a second medication, called naloxone, which limits the opioid effect it can produce. For these reasons, methadone abuse potentially poses a more serious problem for an affected individual than buprenorphine abuse. Benzodiazepines Benzodiazepines are a group of medications also known as tranquilizers, sedatives or sedative-hypnotics. When introduced into the body, they substantially slow the rate of communication between the nerve cells that populate the central nervous system (brain and spinal cord); for this reason, doctors may also refer to them as depressants or central nervous system depressants. Common examples of benzodiazepines prescribed in the U.S. include alprazolam (Xanax), triazolam (Halcion) and diazepam (Valium). Potential uses for these medications include the relief of panic attacks and other forms of medically serious anxiety and the encouragement of sleepiness in people affected by insomnia or certain other sleep disorders. People who use benzodiazepines run the risk of developing the symptoms of physical dependence, even when they use the medications as instructed by their doctors. Benzodiazepine abusers, in particular, have increased odds of compounding the presence of physical dependence with the symptoms of full-blown addiction. Consequences of Simultaneous Abuse Addiction specialists and public health officials refer to the simultaneous abuse of two or more addictive substances as polysubstance abuse. In the study published in Drug and Alcohol Dependence, researchers from the University of Maryland School of Medicine, the Maryland Poison Control Center, the Johns Hopkins University School of Medicine and the Hennepin Regional Poison Control Center used an examination of 764 adults age 18 or older to compare the health impact of polysubstance abuse involving methadone and benzodiazepines to that of polysubstance abuse involving buprenorphine and benzodiazepines. Six hundred ninety-two of the participants were involved in methadone-benzodiazepine abuse, while the remaining 72 simultaneously abused buprenorphine and benzodiazepines. Information on the health outcomes of all 764 participants came from data submitted to the American Association of Poison Control Centers between late 2002 and the end of 2010. After reviewing the gathered data, the researchers concluded that both the methadone-benzodiazepine abusers and the buprenorphine-benzodiazepine abusers experienced seriously negative health outcomes that included lethargic body responses, abnormally shallow breathing, coma and low blood pressure. However, the methadone-benzodiazepine abusers had higher risks for all of these problems than the buprenorphine-benzodiazepine abusers. In addition, some of the methadone-benzodiazepine abusers had two severely negative health outcomes not seen among the buprenorphine-benzodiazepine abusers: the complete suspension of breathing known as respiratory arrest and the complete suspension of heart function known as cardiac arrest. All told, the methadone-benzodiazepine abusers required hospitalization 24 percent more often than the buprenorphine-benzodiazepine abusers. In addition, while 16 of the methadone-benzodiazepine abusers died, none of the buprenorphine-benzodiazepine abusers died. Significance and Considerations The authors of the study published in Drug and Alcohol Dependence narrowed their focus on toxic reactions to the simultaneous abuse of methadone or buprenorphine and benzodiazepines. For this reason, they did not look at all of the potential outcomes of polysubstance abuse involving these medications. The study\u2019s authors note that methadone-benzodiazepine abusers experiencing toxic reactions also end up in intensive care units in hospitals substantially more often than buprenorphine-benzodiazepine abusers experiencing toxic reactions.