A guest column by the American Society of Anesthesiologists, exclusive to KevinMD.com.

Before undergoing surgery, you should carefully discuss your medications with your surgeon and physician anesthesiologist. You may fare better during the operation and the early recovery phase if you continue required medications, but you might need to avoid some medications that could interfere with your anesthesia. Three medical conditions and associated medications that should help improve your chances of a speedy and healthy recovery are examined below.

Hypertension

When your blood pressure is too high, you have a condition known as hypertension. Physicians prescribe medications to treat this condition, but some may drop your blood pressure too low if they interact with anesthesia. In general, we recommend that patients who take beta-blockers like metoprolol (generic names that end in
“-olol or ilol”) continue taking them on the day of surgery. Clonidine (often prescribed as a transdermal patch) is considered a treatment for chronic hypertension, and in general, we recommend continuing this medication to avoid an episode of temporary high blood pressure that may cancel your surgery. When taking hydrochlorothiazide (HCTZ) for hypertension, we also suggest continuing it on the day of surgery.

Two other classes of antihypertensive agents may cause dangerously low blood pressures: angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs). ACE inhibitors work by blocking the formation of angiotensin II, a protein that usually “tightens” your arterial blood vessels. ARBs directly block angiotensin II receptors inside the wall of your arteries, receptors that make the arteries constrict. We suggest you stop taking ACE-inhibitors, e.g., lisinopril, ramipril or agents ending with “-pril,” as well as ARBs, such as losartan, valsartan and meds ending with “-sartan,” on the day before surgery unless you are on these drugs for heart failure rather than high blood pressure.

Heart disease and clotting disorders

Physicians often prescribe aspirin for patients who have coronary artery disease (CAD). Aspirin works by inhibiting platelets, reducing the risk of clotting of the coronary arteries, and lowering your risk of a heart attack. If you are taking 81 mg of “baby” aspirin, you can continue taking it up to the day of surgery. If you are taking 325 mg of aspirin, we strongly encourage you to discuss the risk of bleeding with your surgeon and if he or she thinks you should drop the dose to 81 mg for five to seven days prior to your procedure.

According to the American College of Cardiology (2010), patients who have drug-eluting heart stents (DES) should have elective surgical procedures delayed for at least six, but preferably 12, months to reduce the risk of in-stent life-threatening heart attacks. After 12 months of receiving a DES and if there is significant bleeding risk, we recommend stopping clopidogrel (Plavix) or other platelet-inhibiting drugs five to seven days prior to surgery. If your cardiologist is concerned about your risk of heart attack while off clopidogrel, you may discuss “bridging” therapy using a different, short-acting blood thinner with your surgeon. Within 12 months of receiving a DES, you and your surgeon must discuss the risk of bleeding versus the risk of clot, and likely continued use of both aspirin and clopidogrel during the procedure. For patients with bare metal stents, we recommend continuing aspirin and clopidogrel until at least one month, but preferably six, months. Because of the location of your stent or other factors, your cardiologist may wish to continue your blood thinners much longer than a year.  If there is any confusion about whether you should stop your platelet-inhibiting drugs, please contact your heart doctor.

Patients with valvular heart disease, atrial fibrillation or other clotting disorders frequently take warfarin (Coumadin) or other anti-blood thinning medications such as apixaban (Eliquis). We strongly recommend stopping these drugs five to seven days before surgery to reduce your risk of bleeding, but discussion with your cardiologist and surgeon is advised. We also recommend avoiding herbal medications such as gingko biloba and ginseng, for five to seven days prior to surgery, as they increase your risk of bleeding.

Diabetes mellitus

Management of your blood sugar on the day of surgery may be challenging, and we highly recommend discussing your diabetes drug regimen with your endocrinologist or primary care physician prior to surgery. In general, patients with type I diabetes should take a small amount (⅓) of their morning NPH or long-acting insulin on the day of surgery. Patients with Type 2 diabetes should take up to ½ of their normal morning dose of combination (70/30) or long-acting insulin on the day of surgery. If the procedure is particularly long, you may consider taking none at all to avoid low blood sugar. We suggest not taking other oral agents like glyburide or metformin on the day of surgery. Most importantly, however, we urge you to check your blood sugar on the day of surgery prior to going back to the operating room (or any time you feel like your blood sugar may be too low) in order to avoid extremely low blood sugar and the risk of having a stroke.

Chronic pain, anxiety and depression

Chronic pain is becoming increasingly common in the United States, as are pain medication prescriptions. We strongly suggest that patients taking large doses of pain drugs (e.g., 60 mg of morphine per day or a fentanyl patch) discuss pain management options with their surgeon and physician anesthesiologist prior to the surgery. Additionally, the combination drug Suboxone (buprenorphine and naloxone) has very serious implications around the time of surgery.  If you are taking this medication, it may be necessary to consult with pain medicine specialists before your operation in order to formulate a successful pain management plan.  Regional anesthesia techniques (nerve blocks, spinals, epidurals, etc.) are beneficial in many situations. It is extremely important to bring your list of medications to the preop holding area when you meet your physician anesthesiologist. Patients with significant anxiety or depression, in particular, may benefit from continuing medications for these conditions on the day of surgery. Lorazepam (Ativan) helps some patients face a daunting surgery, and acute withdrawal for some antidepressants or other psychiatric medications can be very dangerous and uncomfortable.

Always consult with your physician anesthesiologist and surgeon prior to undergoing surgery to make sure your medication regimen will not negatively impact the anesthesia you are given.

Kent B. Berg and Gregory M. Janelle are anesthesiologists.