Opioids can lower blood pressure. Prescribing information for oxycodone warns that it may cause severe low blood pressure, including sudden drops when standing up and fainting. Withdrawal works the other way, and blood pressure can rise when someone who depends on opioids stops taking them.
Knowing which direction to expect, and which signs need emergency care, matters for anyone taking prescription opioids or worried about a loved one’s use. Information about opioid addiction treatment in South Florida is available if opioid use has become hard to manage.
Do Opioids Lower Blood Pressure?
Yes, opioids can lower blood pressure, and the drop can be serious. The Food and Drug Administration’s prescribing information for oxycodone lists severe hypotension, including orthostatic hypotension and fainting, among the drug’s warnings [1].
Not all patients who take opioids notice a change. Effects vary depending on the drug, the dose, how long a person has taken it, other medications, and their overall health.
Opioids belong to the broader group of drugs that slow the central nervous system, alongside alcohol and sedatives. Our guide to depressant drugs explains how that group is defined and why its members share so many risks.
How Opioids Widen Blood Vessels
Opioids, including oxycodone, hydrocodone, morphine, fentanyl, and buprenorphine, act on opioid receptors in the brain and spinal cord. Those receptors block pain signals, which is how opioid analgesic medications treat pain.
Opioids can also affect blood pressure. The oxycodone label explains that the drug widens blood vessels in the body, which can lead to a drop in blood pressure on standing or to fainting.
The oxycodone label links histamine release and/or widening of blood vessels with itching (pruritus), flushing, red eyes, and sweating. Histamine release varies among opioids, so it should not be assumed to explain every opioid’s effects.
Orthostatic Hypotension: Dizziness When You Stand
Orthostatic hypotension is a drop in blood pressure that happens when a person stands up from sitting or lying down. It can cause dizziness, lightheadedness, or fainting, and a sudden faint can lead to a fall.
The FDA advises people taking opioids to learn the symptoms of low blood pressure and to lower their risk by sitting or lying down when symptoms start and rising slowly. Its medication guide lists lightheadedness when changing positions and feeling faint among the reasons to get emergency help.
Who Faces a Higher Risk of Low Blood Pressure?
The oxycodone label notes increased risk in people whose ability to maintain blood pressure is already weakened by low blood volume, such as from dehydration or blood loss. It also notes increased risk when opioids are combined with certain other drugs that slow the central nervous system, such as some antipsychotic medicines and general anesthetics.
Older patients may be more sensitive to opioids, and the label advises extra caution with dose selection for them.
The risk is also higher when starting opioids or after a dose increase, which is why prescribers check in more often during those periods. Medicines taken hours earlier count too, and our post on how long do benzos stay in your system explains why some benzodiazepines are still active long after a dose.
Combining Opioids With Other Depressants
The FDA warns that using opioids with benzodiazepines or other central nervous system depressants, including alcohol, can cause profound sedation, slowed breathing, coma, and death. These sedative effects add together, and blood pressure and breathing can fall at the same time.
Benzodiazepines and opioids are different drug classes, but they share this danger. The label notes that evidence from observational studies shows combined use of opioids and benzodiazepines raises the risk of drug-related death compared with opioids alone.
Alcohol deserves its own mention. Every alcoholic drink is a depressant, and our post asking is tequila a depressant covers why even drinks with an energizing reputation add to the risk.
Long-Term Use and Adrenal Insufficiency
With long-term use, opioids can affect hormone levels. The label reports cases of adrenal insufficiency, more often after more than one month of use, which can cause nausea, fatigue, weakness, dizziness, and low blood pressure.
These symptoms are easy to blame on something else. Anyone who has taken opioids for a long time and develops ongoing dizziness or weakness should tell their prescriber.
Opioids, Chronic Pain, and Blood Pressure
The oxycodone label describes its use for acute and chronic pain severe enough to need an opioid analgesic when other treatment is inadequate. It advises the lowest effective dose for the shortest duration, and notes that many acute pain conditions, such as pain after surgery, need only a few days of an opioid.
For chronic pain, physicians tailor doses to individual patients and reassess them regularly, since high doses raise the risk of overdose and other severe side effects. Patients treated for chronic pain who also take other medications should report any new dizziness.
Over time, some people develop tolerance, so the same dose may provide less pain relief, while others develop hyperalgesia, where pain sensitivity increases. Both are reasons to review the treatment plan with a prescriber rather than adjust doses alone.
Can Opioids Raise Blood Pressure?
Opioids themselves tend to lower blood pressure, but stopping them can raise it. The DEA lists a rise in heart rate and blood pressure among the later symptoms of opioid withdrawal, along with restlessness, nausea, tremors, and cravings [2].
That rise is one reason stopping opioids suddenly is not recommended. The FDA label warns against abruptly stopping opioids in a person who is physically dependent, because rapid discontinuation has led to serious withdrawal symptoms and uncontrolled pain.
Anyone with high blood pressure who takes opioids, or who plans to stop them, should talk with their prescriber about how changes might affect their readings.
Opioid Overdose and Blood Pressure
In an overdose, blood pressure and heart rate can fall along with breathing. The oxycodone label describes overdose signs that include severe drowsiness progressing to stupor or coma, cold and clammy skin, pinpoint pupils, a slow heart rate, and low blood pressure.
Slowed breathing is the most dangerous part of an overdose, and our post on respiratory depression explains how it develops. Call 911 right away for any suspected overdose.
Give naloxone if an opioid overdose is suspected and it is available. Call 911 even if the person wakes up, because naloxone can wear off before the opioid does. Follow the product instructions for repeat doses; if the person does not respond, another dose may be needed after 2 to 3 minutes. Follow the dispatcher’s instructions for rescue breathing or CPR, and do not delay breathing support while waiting for naloxone to work [3].
Other Severe Side Effects of Prescription Opioids
Low blood pressure is only one of the significant risks of prescription opioids. The label lists nausea, constipation, vomiting, headache, itching, insomnia, dizziness, and drowsiness among the most common side effects.
Rarer but serious effects include opioid-induced hyperalgesia, in which an opioid paradoxically increases pain or sensitivity to pain, and a higher risk of seizures in people with seizure disorders. Opioids are not used for people with severe asthma outside a monitored medical setting.
Prescribed opioids also carry risks of misuse, opioid dependence, and addiction, even at recommended doses. Our post answering are opioids depressants explains how they slow the body and how they compare with sedatives.
Using Prescribed Opioids More Safely
People with chronic pain, cancer-related pain, or severe pain after surgery or injury may be prescribed opioids when other treatments are not enough. A few steps can lower the risk of dangerous side effects, including blood pressure drops:
- Tell your doctor and pharmacist about all other medications, including over-the-counter sleep aids and antihistamines
- Avoid alcohol while taking opioids
- Stand up slowly, and sit or lie down if you feel dizzy or lightheaded
- Do not change your dose or stop suddenly without talking to your prescriber
- Store opioids in a secure place, out of reach of children and visitors
Buprenorphine is a partial opioid agonist used to treat opioid use disorder and, in some formulations, pain. Starting it too soon after a full agonist opioid can trigger withdrawal. For severe acute pain, clinicians may use a short-acting full agonist alongside ongoing buprenorphine in a supervised setting [4]. Do not start, stop, or combine these medicines on your own.
If you also take benzodiazepines, ask how the two interact. Our post on how benzodiazepines differ from opioids explains why the combination carries the FDA’s strongest warning.
Frequently Asked Questions About Opioids and Blood Pressure
Does Oxycodone Bring Down Blood Pressure?
Oxycodone can bring down blood pressure. Its FDA prescribing information warns that it may cause severe low blood pressure, including drops on standing and fainting, partly because it widens blood vessels. The risk is higher with low blood volume, when combined with certain other depressants, and when starting the drug or after a dose increase.
What Do Opioids Do to Your Blood Pressure?
Opioids can lower blood pressure or cause it to drop when you stand up, which can bring dizziness or fainting. Effects vary with the medicine, dose, and person’s health. During withdrawal, blood pressure and heart rate can rise instead. In an overdose, blood pressure, heart rate, and breathing can all fall to dangerous levels, which is a medical emergency.
When Is Low Blood Pressure an Emergency?
Get emergency help if low blood pressure comes with fainting, chest pain, a fast heartbeat, trouble breathing, confusion, or extreme drowsiness. For someone taking opioids, these signs can point to an overdose or a dangerous drug combination. Call 911 rather than waiting to see whether the symptoms pass.
Getting Information and Support
A doctor or pharmacist can explain how a specific opioid might affect your blood pressure and whether it is safe with your other medicines. Keep a list of everything you take and bring it to each appointment.
The Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline at 1-800-662-4357 is free and confidential, and anyone in a mental health or suicide crisis can call or text 988. For signs of overdose, call 911. Simple Path Recovery offers medication-assisted treatment in Pompano Beach as part of its outpatient care.
This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Do not stop or change a prescribed medication without talking to your prescriber. If you are in crisis, call or text 988; for signs of overdose, call 911.
Sources
- U.S. Food and Drug Administration. OXAYDO (oxycodone HCl) Prescribing Information and Medication Guide. Revised April 2024 (Boxed Warning updated December 2023). https://www.fda.gov/media/178921/download
- U.S. Drug Enforcement Administration. Narcotics (Opioids): Drug Fact Sheet. October 2022. https://www.getsmartaboutdrugs.gov/sites/default/files/2022-11/Narcotics%202022%20Drug%20Fact%20Sheet.pdf
- Centers for Disease Control and Prevention, NIOSH. Responding to a Suspected Opioid Overdose. https://www.cdc.gov/niosh/publications/numbered/2019-127.html
- Centers for Disease Control and Prevention. Clinical Practice Guideline for Prescribing Opioids for Pain — United States, 2022. https://www.cdc.gov/mmwr/volumes/71/rr/rr7103a1.htm
