Opioids and benzodiazepines are prescription medicines that can both affect the central nervous system. Opioids are commonly prescribed for certain types of moderate to severe pain, while benzodiazepines may be prescribed for conditions such as severe anxiety, seizures or other specific medical indications.

Taking these medicines together can be dangerous because their effects can add together. The combination can cause profound sedation, slowed or difficult breathing, coma and, in severe cases, death.

For this reason, opioids and benzodiazepines should only be used together when specifically prescribed and carefully monitored by a healthcare professional.

What Are Opioids?

Opioids are medicines that act on opioid receptors in the nervous system to reduce pain. Examples include:

• Morphine
• Oxycodone
• Fentanyl
• Codeine
• Tramadol
• Dihydrocodeine
• Methadone

Opioids can also cause drowsiness and suppress breathing, particularly at higher doses or when combined with other medicines that have sedative effects.

What Are Benzodiazepines?

Benzodiazepines are medicines that enhance the effects of GABA, an inhibitory neurotransmitter in the brain. Depending on the medicine and its indication, they may be prescribed for anxiety, insomnia, seizures or other conditions.

Examples include:

• Lorazepam
• Clonazepam
• Alprazolam
• Diazepam
• Temazepam
• Nitrazepam

Benzodiazepines can cause sedation, drowsiness, impaired coordination and reduced alertness.

Why Is Combining Them Dangerous?

Both opioids and benzodiazepines can depress activity in the central nervous system.

When they are taken together, their sedative effects can become significantly stronger. This can lead to:

• Extreme sleepiness
• Confusion
• Poor coordination
• Reduced consciousness
• Slowed or difficult breathing
• Loss of consciousness
• Coma
• Potentially fatal overdose

The risk is particularly important in people who are taking high doses, are older, have respiratory conditions or are using other medicines or substances that cause sedation.

Respiratory Depression

One of the most serious concerns is respiratory depression, where breathing becomes unusually slow or shallow.

A person experiencing severe respiratory depression may:

• Become extremely difficult to wake
• Have slow, shallow or irregular breathing
• Make unusual snoring or choking sounds
• Develop pale, blue or grey lips or skin
• Lose consciousness

This is a medical emergency.

If someone appears to have overdosed or is having difficulty breathing after taking opioids, benzodiazepines or other sedatives, call emergency medical services immediately.

The Risk of Overdose

Combining opioids and benzodiazepines can increase the risk of overdose because both medicines can suppress the central nervous system.

An overdose may initially appear as unusually severe sleepiness but can progress to unconsciousness and life-threatening breathing problems.

The risk can be even greater when other depressants, particularly alcohol, are involved.

Alcohol and Other Sedatives

Alcohol can further increase the sedative effects of opioids and benzodiazepines.

Other medicines that can contribute to excessive sedation may include:

• Sleeping medicines
• Certain antihistamines
• Other sedative medicines
• Some medicines used for anxiety
• Other central nervous system depressants

Always tell your doctor or pharmacist about all medicines, supplements and substances you use.

Are Opioids and Benzodiazepines Ever Prescribed Together?

In some circumstances, a healthcare professional may decide that a patient needs both medicines.

However, this combination requires careful consideration because of the increased risk of sedation and respiratory depression.

If both medicines have been prescribed, take them exactly as directed. Do not increase either dose or add another sedating medicine without speaking with your doctor or pharmacist.

Who May Be at Greater Risk?

The risks can be higher for people who:

• Are older or frail
• Have chronic respiratory disease
• Have sleep apnoea
• Have liver or kidney problems
• Take higher doses of either medicine
• Use alcohol or other sedatives
• Have a history of substance dependence
• Take multiple medicines that affect the central nervous system

Your healthcare professional can assess your individual risk before prescribing these medicines together.

Signs That Require Urgent Medical Attention

Seek emergency medical assistance if someone taking opioids and benzodiazepines develops:

• Very slow or difficult breathing
• Severe difficulty staying awake
• Loss of consciousness
• Blue, grey or pale lips or skin
• Unresponsiveness
• Severe confusion
• Suspected overdose

Do not assume that someone who is unconscious will simply sleep it off. A suspected overdose requires urgent medical assessment.

How Can the Risks Be Reduced?

If you have been prescribed an opioid and a benzodiazepine:

1. Take both medicines exactly as prescribed.
2. Do not increase either dose without medical advice.
3. Avoid alcohol unless your healthcare professional specifically tells you otherwise.
4. Do not take additional sedative medicines without checking first.
5. Tell your doctor or pharmacist about every medicine you take.
6. Do not share prescription medicines with another person.
7. Do not suddenly stop a regularly used benzodiazepine without medical advice.

If you are concerned about the combination of medicines you have been prescribed, speak with your doctor or pharmacist before making changes.

Frequently Asked Questions

Why should opioids and benzodiazepines not usually be combined?

Both can depress the central nervous system. Taking them together can increase sedation and the risk of respiratory depression, coma and potentially fatal overdose.

Can mixing opioids and benzodiazepines cause breathing problems?

Yes. Both types of medicine can suppress breathing, and their combined effects can make respiratory depression more likely.

Is it safe to drink alcohol with opioids and benzodiazepines?

Alcohol can substantially increase sedation and other risks. It should generally be avoided when taking these medicines.

What should I do if I accidentally take both?

If both medicines were prescribed to you, follow your prescription and contact your doctor or pharmacist if you are concerned. If you have taken more than prescribed or develop severe drowsiness, difficulty breathing or loss of consciousness, seek emergency medical help immediately.

Should I stop my benzodiazepine if I am also taking an opioid?

Do not make medication changes without medical advice. Suddenly stopping a regularly used benzodiazepine can cause withdrawal symptoms and, in some circumstances, serious complications. Speak with your prescriber about the safest approach.

Can a pharmacist check whether my medicines interact?

Yes. A pharmacist can review your prescription and non-prescription medicines and identify potential interactions or safety concerns.

Cura Point Pharmacy

Understanding how medicines interact is an important part of using prescription treatments safely. Opioids and benzodiazepines can both provide important benefits when appropriately prescribed, but their combined effects require particular caution.

If you have questions about your medicines, speak with your doctor or pharmacist before changing your treatment.