A. Introduction. Medication management must be addressed for all patients undergoing surgery. This chapter outlines perioperative medication management for the most common medication classes. See Chapter 95 for more detailed information on the perioperative management of β-blockers, statins, and aspirin.
B. General Principles
a. Most medications are well-tolerated in the perioperative period and do not interfere with anesthesia. It is advised to take adequate water with pills, including on the day of surgery.
b. Medications with potential rebound or withdrawal effects should be continued perioperatively. Common agents in this class include benzodiazepines, opioids, corticosteroids, α-agonists (e.g., clonidine), and β-blockers.
c. Medications with known perioperative benefit should be continued without missing doses. Examples of such medications include β-blockers, statins, and low-dose aspirin in patients with coronary stents.
d. Supplements, herbal medications, and most vitamins should be discontinued 1–2 weeks before surgery. The specific ingredients of many of these agents are unknown, while some have shown to cause adverse events including bleeding. For example, it is known that the “3 Gs” (garlic, ginkgo, and ginseng) can inhibit platelet function.
C. Medication Classes
i. Calcium channel blockers, β-blockers, and α-agonists (e.g., clonidine) should be continued on the day of surgery.
ii. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) can either be held or given on the morning of surgery depending on blood pressure. Although the data are conflicting on the risks and benefits of perioperative exposure to these agents, it is clear that these agents increase the risk for hypotension upon anesthesia induction. If held on the morning of surgery, it is important to restart these agents as soon as clinically feasible after surgery.
iii. Diuretics, including loop and thiazide diuretics, are commonly held on the morning of surgery. However, one small randomized trial of taking versus holding loop diuretics on the morning of surgery showed no difference in hypotension, cardiovascular events, renal function, or electrolyte derangement.
c. Diabetes mellitus
i. Oral agents are generally held for the duration of hospitalization. This is due to unpredictable food intake, inability to quickly titrate these agents, and risk for potential exposure to intravenous (IV) contrast, which may increase risk of renal failure and lactic acidosis if given while taking metformin.
1. In type 2 diabetes, 50–75% of the patient’s normally scheduled basal insulin dose should be given before surgery. This can be tailored depending on the patient’s baseline blood sugar control.
2. In type 1 diabetes, 100% of basal insulin is continued on the day of surgery.
3. Rapid-acting insulin is held on the day of surgery because patients are typically “NPO” for the operating room.
i. Antidepressants, antipsychotics, and dementia medications should be continued perioperatively without missing doses.
ii. Although rarely used, monoamine oxidase inhibitors (MAOIs) should be stopped 2 weeks before surgery if possible. MAOIs can interact with anesthetic agents and trigger a hypertensive crisis or serotonin syndrome.
i. All seizure medications should be continued perioperatively.
ii. Medications for Parkinson’s disease should be continued without missing doses. Medications such as carbidopa/levodopa should be administered on the morning of surgery, relatively close to anesthesia induction.
Abrupt discontinuation of Parkinson’s disease medications can lead to an acute disease flare or neuroleptic malignant syndrome.
f. Rheumatologic agents/immunomodulators
i. It is important to balance the risks of continuing these agents (e.g., increased infection, compromised wound healing) against the risks of discontinuing them (risk for disease flare) before surgery.
ii. Methotrexate. This is the most studied rheumatologic agent (mostly in orthopedic surgery) and appears to be generally safe to continue perioperatively. Exceptions include surgery to treat serious infections, in which case methotrexate should be held.
iii. Tumor necrosis factor-α (TNF-α) antagonists (e.g., etanercept, infliximab, adalimumab) are typically held for one dosing cycle before major surgery. They are also held for 10–14 days after surgery to ensure satisfactory wound healing. These agents can usually be continued for minor surgeries (e.g., inguinal hernia repair).
iv. Other agents, including hydroxychloroquine, azathioprine, and sulfasalazine, appear to be safe perioperatively.
v. Corticosteroids. Although the risk for acute adrenal crisis is rare in the perioperative setting, a brief course of stress-dose steroids (1–2 days) may be considered for patients on chronic corticosteroids at doses equivalent to prednisone ≥ 5 mg daily or higher. Patients on chronic steroids should continue their home dose throughout the perioperative period without missing doses.
g. Antiplatelet agents
i. Aspirin should be discontinued 5–7 days before surgery in most cases. Exceptions include patients with a coronary stent, in whom low-dose aspirin is typically continued perioperatively.
ii. Patients on dual antiplatelet therapy (DAPT) following placement of a coronary stent require careful consideration. For bare metal stents, surgery should be postponed until 30 days of DAPT have been completed. Following 30 days of uninterrupted DAPT, surgery may be performed while maintaining the patient on low-dose aspirin only. For drug-eluting stents, the following is recommended based on time from stenting:
1. Less than 3 months: delay surgery
2. More than 6 months: proceed with surgery with low-dose aspirin only
3. Between 3 and 6 months: risk/benefit analysis of proceeding vs. delaying surgery is required
iii. P2Y12inhibitors (e.g., clopidogrel, prasugrel, ticagrelor) should be held 7 days before surgery.
iv. Nonsteroidal antiinflammatory drugs (NSAIDs) are typically held 3–7 days before surgery depending on the drug’s half-life. Note that the cyclooxygenase-2 (COX-2) inhibitor celecoxib does not need to be held before surgery because it does not inhibit platelet function.
h. Antithrombotic agents
i. Warfarin. For most surgeries, warfarin needs to be stopped 5 days before surgery. Most surgeries can be safely performed when the international normalized ratio (INR) is ≤1.4. Some procedures do not require warfarin cessation; examples include cataract surgery, upper endoscopy, colonoscopy without biopsy, most dental procedures, many dermatologic procedures, and joint aspiration/injections.
ii. Bridging therapy (use of a short-acting anticoagulant such as low-molecular-weight heparin while the patient’s INR is subtherapeutic) should only be considered in few clinical scenarios. These include:
1. Atrial fibrillation with recent stroke (<3 months)
2. Atrial fibrillation with a very high stroke risk (CHADS2 = 5 or 6)
3. Recent venous thromboembolism (<3 months)
4. Patients with a mitral mechanical valve or older model aortic mechanical valves
5. Patients with recurrent venous thromboembolism and a known severe thrombophilia (e.g., antiphospholipid antibody syndrome, protein C or S deficiency, antithrombin III deficiency)
iii. Direct oral anticoagulants (DOACs). These include a direct thrombin inhibitor (dabigatran) and the factor Xa inhibitors (rivaroxaban, apixaban, and edoxaban). DOACs have a half-life much shorter than warfarin and therefore do not require bridging anticoagulation perioperatively. These agents are typically stopped 1–2 days before surgery; however, the window of cessation can be extended to 3 or 4 days for patients with advanced renal insufficiency or if undergoing a procedure with a high bleeding risk to allow for complete drug clearance before surgical intervention.
Suggested Further Readings
Daniels PR. Peri-procedural management of patients taking oral anticoagulants. BMJ 2015;351.Find this resource:
Devereaux PJ, Mrkobrada M, Sessler DI, et al. Aspirin in patients undergoing noncardiac surgery. N Engl J Med 2014;370:1494–503.Find this resource:
Douketis JD, Spyropoulos AC, Kaatz S, et al. Perioperative bridging anticoagulation in patients with atrial fibrillation. N Engl J Med 2015;373:823–33.Find this resource:
Levine GN, Bates ER, Bittl JA, et al. 2016 ACC/AHA guideline: Focused update on duration of dual antiplatelet therapy in patients with coronary artery disease. A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines: an update of the 2011 ACCF/AHA/SCAI guideline for percutaneous coronary intervention, 2011 ACCF/AHA guideline for coronary artery bypass graft surgery, 2012 ACC/AHA/ACP/AATS/PCNA/SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease, 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction, 2014 AHA/ACC guideline for the management of patients with non–ST-elevation acute coronary syndromes, and 2014 ACC/AHA guideline on perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery. Circulation 2016;134:e123.Find this resource: