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Methadone and Benzodiazepines: A Deadly Polydrug Combination

Isaac Alexis, M.D., AAMA, AMP-BC

Medically reviewed by

Isaac Alexis, M.D., AAMA, AMP-BC

February 19, 2019

Mixing different drugs can cause them to react to each other and leave an individual facing serious health consequences. Taking methadone and benzodiazepines together is extremely dangerous and could lead to a fatal overdose.

Substance abuse can greatly affect a person’s health and life, from mental and physical health to daily obligations. Abusing substances can cause long-term adverse side effects and may cause an addiction which is extremely difficult to overcome. Abusing two substances, then, can be twice as dangerous as abusing one. In fact, some substance combinations can cause serious health complications or even fatal overdose. One such combination is methadone and benzodiazepines.

What Are These Drugs?

Methadone is a medication that was developed for use in treating those in recovery from heroin or prescription opioids, as well as other narcotics. When it is taken as prescribed, it may be safe and is typically non-addictive, however, it may form a physical dependence. People who have fallen victim to opioid abuse may experience a physical dependency on these drugs, meaning they may have severe withdrawal symptoms when they try to stop use. Methadone allows people to wean off the drug by essentially replacing its effects, slowly tapering use over time. Patients require treatment with methadone for a minimum of 12 months but may need it for years, according to the Substance Abuse and Mental Health Services Administration (SAMHSA). Unfortunately for those in treatment, methadone can also be addictive, so it is important to take it exactly as prescribed, with monitorization as needed.

Benzodiazepines are depressant medications used to treat many different mental or physical conditions. There are more than 15 types of benzodiazepines available for prescription today, according to the Center for Substance Abuse Research (CESAR). To be classified as this type of drug, a medication must produce one or more of the following effects: anticonvulsant, amnesiac (produces mild memory loss), hypnotic, muscle relaxation, or relief of anxiety. Some examples of common benzodiazepines are Valium, Xanax, and Librium.

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What Happens When These Drugs Are Abused?

Methadone is a long-acting drug, which means it remains in the body for a long time, even if the person taking it does not feel its effects. This is why it should be taken with caution and not abused. People taking methadone for substance abuse treatment may experience a number of side effects, including constipation, dizziness, drowsiness, and nausea or vomiting. But when use turns into abuse, people may be at heightened risk for addiction and overdose. Overdose may occur due to increased dosage or a buildup of substances over time.

Some signs of overdose for methadone include:

  • Cold or clammy skin
  • Confusion
  • Dizziness
  • Drowsiness
  • Feeling very weak
  • Heightened anxiety
  • Severe restlessness
  • Shallow breathing

Benzodiazepines are prescribed for calmness, relaxation, tension release, and even sleeping problems.

Some general side effects include:

  • Changes in motor coordination
  • Change in thoughts and/or memory
  • Confusion
  • Constipation
  • Drowsiness and lethargy or fatigue
  • Depression
  • Diarrhea
  • Dry mouth
  • Lack of appetite
  • Nausea
  • Slurred speech or stuttering
  • Stomach cramps
  • Tremors
  • Vertigo
  • Vision changes
  • Vomiting

Taken in higher doses, this class of medications may also impact a person’s mood, reflexes, general behavior, and produce a feeling of euphoria. Benzodiazepines may also affect a person after stopping use or abuse, causing confusion, changes to memory or thinking, loss of coordination, disorientation, muscle weakness, and slurred speech.

Why Are These Drugs Dangerous Together?

Combining methadone and benzodiazepines into a polydrug combination could create dangerous results. Polydrug, also called multiple drug use, is defined by the World Health Organization (WHO) as, “the use of more than one drug or type of drug by an individual, often at the same time or sequentially, and usually with the intention of enhancing, potentiating, or counteracting the effects of another drug.” This type of drug use has a history within the United States and is on the rise. An article from the U.S. National Library of Medicine states, “such abuse has been increasingly reported in emergency room admissions and has been linked to drug-related deaths as well as non-fatal overdoses.”

Why is abusing multiple substances potentially dangerous? As previously mentioned, each of these substances comes with a host of possible side effects, all of which may be enhanced or prolonged due to abuse. Combine these effects and you may have a recipe for disaster. Some serious side effects experienced by people who have abused both methadone and benzodiazepines include lethargy, slowed or changed body responses (such as reflexes), extremely shallow breathing, low blood pressure, and in severe cases, coma. Some people have even stopped breathing (respiratory arrest) or experienced their heart stopping (cardiac arrest), which may or may not be fatal.

What Can Be Done?

Though it is clear that abusing these two substances could have disastrous results, it may be possible to stop use with help in treatment. Professional rehab facilities, especially those which provide residential, monitored care, may provide the support addicted individuals need to recover from polydrug abuse. People may receive medication-assisted therapy (MAT), counseling, monitoring to reduce the risk of relapse, and education about their addictions. The behavioral therapy treatment method may help people learn to abstain from drug abuse and create healthy, fulfilling lifestyles. After an inpatient stay, those recovering may be able to participate in support groups, or 12-step programs to help keep them on track and drug-free for the long term. Whatever the case, treatment is available to those who need it.

Get Help For Polydrug Abuse

If you know someone who is suffering from polydrug abuse, then perhaps you recognize how hard it is to overcome addiction. Despite this, people may overcome addiction with the right help. By contacting us at today, you will be connected with people who can design a treatment plan that is suited to your needs.

Center For Substance Abuse Research - Benzodiazepines

U.S. National Library Of Medicine - Mono- Vs. Polydrug Abuse Patterns Among Publicly Funded Clients

Substance And Mental Health Services Administration - Methadone

World Health Organization - Lexicon Of Alcohol And Drug Terms

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