The Critical Need for Full Disclosure to Your Anesthesiologist
Undergoing surgery requires a partnership between you and your medical team, with the anesthesiologist playing a vital role in keeping you safe and comfortable. General anesthesia involves powerful medications that suppress critical body functions like breathing, heart rate, and circulation. What many people don't realize is that common substances—from daily medications to herbal teas—can significantly interact with anesthetic drugs, leading to potentially dangerous complications. These interactions can alter the amount of anesthesia you need, cause cardiovascular instability, or increase your risk of bleeding. For this reason, providing a complete and honest history of everything you take is not just a formality; it is a crucial step for a safe surgical outcome. Most patients using herbal remedies fail to report them, creating a significant information gap for the medical team.
Prescription Medications and Anesthesia
Many chronic conditions require daily medication, and while some are safe to continue, others must be stopped or adjusted before surgery. Always consult with your surgeon and prescribing physician about your specific medications.
Blood Thinners (Anticoagulants/Antiplatelets)
Drugs like warfarin (Coumadin), clopidogrel (Plavix), apixaban (Eliquis), and even daily aspirin are designed to prevent blood clots. However, during surgery, this effect dramatically increases the risk of excessive bleeding. Anesthesiologists and surgeons need to manage this risk, and patients are typically instructed to stop these medications anywhere from 3 to 10 days before their procedure, depending on the specific drug.
Blood Pressure and Heart Medications
Medications like beta-blockers (e.g., metoprolol, atenolol) are often continued up to surgery to maintain heart stability. However, other types, such as ACE inhibitors and ARBs, may be held on the day of surgery because they can cause a significant drop in blood pressure when combined with anesthesia. Diuretics, or "water pills," might also be paused to prevent dehydration.
Diabetes Medications
Managing blood sugar is crucial. While some oral medications may be held, insulin dosages often need to be adjusted the day before and the day of surgery to prevent dangerously low blood sugar levels while fasting. Newer weight loss and diabetes drugs like semaglutide (Ozempic) can delay stomach emptying, increasing aspiration risk, and may need to be stopped a week or more before surgery.
Antidepressants and Psychiatric Medications
A class of antidepressants known as Monoamine Oxidase Inhibitors (MAOIs) can cause severe, dangerous interactions with anesthetic agents, often requiring them to be stopped weeks in advance. Other antidepressants, like SSRIs, are typically continued to prevent withdrawal.
Over-the-Counter (OTC) Drugs and Herbal Supplements
Just because something is available without a prescription doesn't mean it's harmless. The FDA regulates supplements differently than drugs, meaning their contents and effects can be unpredictable. The American Society of Anesthesiologists recommends stopping all herbal medications 2-3 weeks before surgery to be safe.
Common OTC Pain Relievers
Non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen (Advil, Motrin) and naproxen (Aleve) have a blood-thinning effect similar to aspirin and should be stopped about a week before surgery to reduce bleeding risk.
Popular Herbal Supplements with Major Risks
- St. John's Wort: Often used for anxiety or depression, it can prolong the effects of anesthesia. It functions similarly to MAO inhibitors, creating a risk for significant drug interactions.
- Ginkgo Biloba, Garlic, Ginger, and Ginseng: All of these can increase the risk of bleeding. Ginseng can also cause a rapid heartbeat and high blood pressure.
- Valerian and Kava: Used for anxiety and sleep, these supplements are sedatives and can dangerously increase the effect of anesthetic agents.
- Vitamin E: This vitamin has anti-clotting properties and can prolong bleeding time during surgery.
- Ephedra (Ma-Huang): A component in some weight-loss supplements, ephedra is a stimulant that can lead to dangerous spikes in blood pressure and heart rate.
Lifestyle and Recreational Substances
Honesty about alcohol, tobacco, and cannabis use is essential for your safety. These substances have powerful physiological effects that directly clash with anesthetic drugs.
Alcohol
Chronic alcohol use can damage the liver, which changes how the body processes anesthetic drugs. This may mean a higher dose of anesthesia is required. Acute alcohol use thins the blood, increasing bleeding risk. Suddenly stopping alcohol before surgery can trigger severe withdrawal, a medical emergency in itself.
Tobacco and Cannabis
Smoking damages the lungs and makes airways more sensitive, increasing the risk of breathing problems like bronchospasm during surgery. Cannabis (marijuana) use can also lead to higher anesthetic requirements and can increase post-operative pain. Anesthesiologists recommend stopping smoking and cannabis use as far in advance of surgery as possible.
Comparison of Common Interferences
| Substance Class | Examples | Primary Anesthetic Interaction(s) | General Recommendation |
|---|---|---|---|
| Blood Thinners | Aspirin, Plavix, Warfarin, Ibuprofen | Increased risk of serious bleeding. | Stop 3-10 days before surgery, per physician instruction. |
| Herbal Supplements | St. John's Wort, Ginkgo, Ginseng | Can increase bleeding, alter blood pressure, or prolong anesthesia effects. | Stop all supplements at least 1-2 weeks before surgery. |
| Alcohol | Beer, wine, liquor | Alters anesthetic dose requirements; increased bleeding risk; risk of withdrawal. | Stop drinking at least two weeks before surgery. Be honest about chronic use. |
| Cannabis | Marijuana (smoked, edible) | May require higher doses of anesthesia; increases post-op pain; airway irritability. | Stop use as far in advance as possible; do not use on the day of surgery. |
| Certain Antidepressants | MAOIs (Nardil, Parnate) | Can cause life-threatening hypertensive crisis with certain anesthetic drugs. | Must be stopped several weeks prior to surgery under medical supervision. |
Conclusion: Your Safety Is a Team Effort
Does anything interfere with anesthesia? The answer is a resounding yes. A wide array of prescription drugs, OTC products, herbs, and lifestyle habits can pose significant risks during surgery. The single most important step you can take to mitigate these risks is to have an open and honest conversation with your anesthesiologist. Bring a comprehensive list of everything you take—including dosage and frequency—to your pre-operative appointment. Full transparency allows your medical team to create the safest possible anesthetic plan tailored specifically to you. Your life depends on it.
For more information from an authoritative source, please visit the American Society of Anesthesiologists at asahq.org/madeforthismoment.
