Medications
Beta Blockers Before Surgery
If you take a beta blocker for your blood pressure, heart, irregular heartbeat, anxiety or migraine, the usual advice before surgery is to keep taking it. Stopping on your own can be more dangerous than continuing.
Quick answer
Why it matters
Beta blockers slow and steady your heart rate and lower blood pressure. If you have been taking one regularly, your body adjusts to it. Stopping abruptly can cause a rebound effect: your heart rate can race and your blood pressure can spike, which is exactly the kind of stress you want to avoid around an operation.
This rebound is especially risky if you take a beta blocker for heart disease, such as angina or after a heart attack, where a sudden surge can strain the heart. For that reason, the standard approach is to continue your usual beta blocker through the whole perioperative period, including the morning of surgery, taken with a sip of water.
One important nuance: while continuing an established beta blocker is recommended, your team will usually not start a brand-new beta blocker just before surgery, because starting one fresh at this point can do more harm than good. So the rule is steady as you go on what you already take, and let the team decide about any new medicine.
Do not stop without instruction
What to ask your doctor
- Should I take my beta blocker on the morning of surgery, and at what time?
- I also take a blood pressure medicine such as an ACE inhibitor or water tablet (diuretic) should I take or hold that?
- If I am admitted and miss a dose, how will my heart rate and blood pressure be managed?
- Are there any reasons in my case to change the dose or pause my beta blocker before the operation?
Red flags — call your team
Red flags — call your team
- A very slow pulse (well below your normal) with dizziness, fainting or feeling about to pass out before surgery
- A racing or pounding heartbeat, chest pain or breathlessness, especially if you have missed doses
- Your heart rate or blood pressure readings are far outside your usual range when checked at pre-assessment
References
- Major anaesthetic and cardiology guidance (for example from professional perioperative and cardiovascular societies) advises continuing established beta blockers through surgery, including the day of operation, and warns against stopping them abruptly or starting a new beta blocker just before surgery.
- This page is general information. Your own surgical and anaesthetic team's instructions always take precedence over anything written here, as they know your full history.
Frequently asked questions
Do I take my beta blocker on the morning of surgery if I am fasting?
Yes, in almost all cases. Fasting means no food and usually no large drinks, but you can take essential tablets with a small sip of water. Beta blockers are normally on the continue list, so take your usual morning dose at your normal time unless your anaesthetist has specifically told you to hold it. If in doubt, call your pre-assessment team the day before.
What if I forgot to take my beta blocker before coming in?
Tell the nursing or anaesthetic team as soon as you arrive. A single missed dose is usually manageable, and they can check your heart rate and blood pressure and give a dose if needed. The main thing is not to hide it, because they may want to monitor you a little more closely or give the medicine in hospital before you go to theatre.
Will the anaesthetist start me on a beta blocker just for the surgery?
Usually not. Continuing a beta blocker you already take is recommended, but starting a brand-new one in the days right before surgery is generally avoided, because beginning treatment at that point can cause more problems than it prevents. Any decision to start a new heart medicine is made carefully by your doctors, not as a last-minute step before your operation.
I take propranolol for migraine or anxiety, not my heart. Same advice?
Broadly yes, the usual advice is to continue it. Propranolol still affects your heart rate and blood pressure even when you take it for migraine or anxiety, so stopping suddenly can cause a rebound. Take your normal dose, including on the morning of surgery with a sip of water, unless your team tells you otherwise. Mention the reason you take it during pre-assessment.