Do Benzodiazepines Cause Respiratory Depression?

What Respiratory Depression Means

Respiratory depression is breathing that has become too slow or too shallow. Each breath moves less air, so carbon dioxide builds up in the blood and the oxygen level falls. In an overdose, this is usually what proves fatal: the National Institute on Drug Abuse (NIDA) says opioids and benzodiazepines can both "cause sedation and suppress breathing," and that suppressed breathing is "the cause of overdose fatality."

How Benzodiazepines Act on Breathing

Benzodiazepines strengthen the effect of GABA, the brain's main calming chemical messenger. That calming effect is why they are prescribed for anxiety and insomnia, and it also reaches the brainstem centers that keep us breathing without thinking about it. The benzodiazepines most people know are alprazolam (Xanax), clonazepam (Klonopin), diazepam (Valium) and lorazepam (Ativan).

On their own, though, benzodiazepines are not the main breathing danger. A review in the Journal of Pharmacy Practice calls them "relatively safe agents in overdose" when taken alone, and a clinical summary on benzodiazepine overdose in the Canadian Medical Association Journal notes that sedation is common but severe respiratory depression is rare. National death records show the same thing from the other side. Of the 118,208 benzodiazepine-involved overdose deaths in the United States from 2000 to 2019, opioids were involved in 83.5%, and only about 9% involved none of the other drugs the researchers tracked: opioids, cocaine, other stimulants, barbiturates or alcohol.

So when a family is worried about breathing, the more useful questions are what else he is taking, and whether his breathing is already vulnerable.

What Changes When Opioids Are in the Picture

Opioids slow breathing through their own receptors and benzodiazepines through GABA, so together they press on the same system from two directions. In 2016 the U.S. Food and Drug Administration (FDA) required its strongest warning, a boxed warning, on opioid pain and cough medicines and on benzodiazepines, because using them together had been linked to serious side effects, including slowed or difficult breathing and deaths.

The two meet often. In 2021, nearly 14% of overdose deaths involving opioids also involved benzodiazepines, according to NIDA. Seen from the benzodiazepine side, a Centers for Disease Control and Prevention (CDC) analysis of deaths in 23 states found that in the first half of 2020, 92.7% of benzodiazepine-involved overdose deaths also involved opioids, and two-thirds involved illicitly made fentanyl. NIDA also reports that benzodiazepines have turned up in the illicit opioid supply in some areas, so some people take the combination without knowing it.

Alcohol Adds to the Same Effect

Alcohol also strengthens GABA's calming effect, and it dampens one of the brain's main excitatory signals as well. The National Institute on Alcohol Abuse and Alcoholism (NIAAA) lists the risks of drinking with Ativan, Klonopin, Valium or Xanax as drowsiness, dizziness, an increased risk of overdose, slowed or difficult breathing, impaired motor control, unusual behavior and memory problems.

Alcohol often appears alongside opioids too. In 2017 it was involved in 14.7% of opioid overdose deaths in the United States, and benzodiazepines in 21.0%, according to a study in JAMA Network Open. An earlier version of this page described that 14.7% as a share of deaths involving opioids or benzodiazepines; the study measured opioid overdose deaths. Sleeping pills and gabapentin are covered in the questions further down.

Who Is Most at Risk?

Four groups have less room for error: older adults, people with lung disease, people with sleep apnea, and anyone taking higher doses or using the medicine in ways it was not prescribed. Each rests on a specific study or on the FDA's own warning, and each comes with limits worth knowing.

Older adults. In Ontario, nearly a third of adults 66 and older with chronic obstructive pulmonary disease (COPD) were given a new benzodiazepine over a five-year period, and the researchers point out that older adults clear these drugs more slowly, so they stay in the body longer.

People with lung disease. Among those older adults with COPD, starting a benzodiazepine was associated with more outpatient flare-ups and nearly double the risk of an emergency room visit for COPD or pneumonia within 30 days, compared with similar people who did not start one.

People with sleep apnea. In obstructive sleep apnea, the airway already narrows or closes during sleep. A study of people with the condition in Taiwan found that both recent and longer-term benzodiazepine use were associated with acute respiratory failure. The study was small and its estimates are wide, but the direction matches the COPD research.

Higher doses and misuse. The FDA's 2020 boxed warning for the whole class says abuse and misuse "can result in overdose or death, especially when benzodiazepines are combined with other medicines," naming opioid pain relievers, alcohol and illicit drugs. Among U.S. veterans prescribed opioids, the risk of overdose death rose with the benzodiazepine dose, as NIDA summarizes that research.

Warning Signs of an Overdose Involving Benzodiazepines

The FDA's 2016 warning names the signs that matter in someone taking an opioid together with a benzodiazepine, another sedating medicine or alcohol:

• unusual dizziness or lightheadedness
• extreme sleepiness
• slowed or difficult breathing
• unresponsiveness

Naloxone (Narcan) reverses opioids, not benzodiazepines, and CDC's analysis of benzodiazepine overdoses explains why it still matters when both drugs are involved: naloxone "reverses opioid overdoses irrespective of benzodiazepine presence," while the benzodiazepine's effects are "unaffected by naloxone and might require additional medical treatment." CDC recommends that people who use opioids and benzodiazepines together carry naloxone. Flumazenil is a separate medicine that can reverse benzodiazepine sedation, and we explain how flumazenil is used in hospitals in its own article.

When the Worry Is the Pattern of Use

Needing a benzodiazepine is not the same as being addicted to it. The FDA notes that physical dependence "can occur when benzodiazepines are taken steadily for several days to weeks, even as prescribed," and its 2020 boxed warning treats abuse, misuse, addiction, physical dependence and withdrawal as separate risks. Dependence matters here for one reason: according to the same warning, stopping abruptly or cutting the dose too quickly can cause withdrawal reactions, including seizures. We explain what benzodiazepine withdrawal involves separately.

The harder worry is a pattern: pills taken beyond the prescription, pills from outside a pharmacy, or benzodiazepines mixed with opioids or drinking. Those are the combinations behind most of the deaths described above, and concerns like these need careful assessment.

Guiding Road provides residential addiction treatment for men in Phoenix, with step-down outpatient care after it, and benzodiazepines are among the substances its programs treat. Detox is not provided on site; when a man needs medical stabilization first, Guiding Road coordinates it with medical partners. The clinical team's assessment looks at substance use alongside concerns such as anxiety, one of the most common reasons benzodiazepines are prescribed, so the plan reflects the person and not only the substance. You can read more about how Guiding Road approaches benzodiazepine use.

If you are weighing this for your husband, son or father, or for yourself, you can talk with Guiding Road's admissions team about the situation, the program and what to expect before making any decision. The admissions line is (480) 588-2328.