A 58-year-old woman comes to the physician for a preoperative evaluation 2 weeks prior to an elective left knee replacement for severe osteoarthritis. Her other medical problems include hypertension, type 2 diabetes, hyperlipidemia, chronic obstructive pulmonary disease, osteoporosis, and gastroesophageal reflux disease. Her medications include amlodipine, atorvastatin, calcium carbonate, metformin, metoprolol, raloxifene, ramipril, pantoprazole, and daily salmeterol and ipratropium bromide metered-dose inhalers. She has no known drug allergies. She does not use tobacco, alcohol, or illicit drugs. Family history is not significant. Her blood pressure is 144/86 mm Hg, pulse is 62/min, and respirations are 12/min. Her BMI is 29 kg/m². Physical examination shows left knee crepitus. Her serum creatinine level is 1.0 mg/dL. Which of the following medications should be discontinued now in preparation for the surgery?

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Explanation: 11ec2b69_be5a_6b97_8f63_29aa91f4f311_MD0005_00 Perioperative medication management is an important part of a patient's preoperative evaluation. Several medications should be continued through the perioperative period, either because they are cardioprotective and reduce the risk of cardiovascular events, or because discontinuation can cause abrupt withdrawal reactions. On the other hand, some medications carry an increased risk of perioperative morbidity/mortality and should be discontinued prior to surgery. Raloxifene is a selective estrogen receptor modulator (SERM) used for breast cancer chemoprevention and for the prevention and treatment of osteoporosis. SERMs (both raloxifene and tamoxifen) are associated with an increased risk of venous thromboembolism. Therefore, it is recommended that these agents be discontinued 4 weeks prior to any surgical procedure associated with a moderate to high risk of venous thromboembolism (eg, knee replacement). Medications (Table) that may be continued until immediately prior to surgery include diuretics, angiotensin-converting enzyme inhibitors (ACE), and angiotensin receptor blockers (ARBs). ACE inhibitors and ARBs are associated with a slightly increased risk of peri- and postoperative hypotensive episodes. However, conclusive evidence for increased risk of cardiovascular complications is lacking. Therefore, these drugs should be withheld the night before surgery (10 hours prior) unless the patient is taking them for heart failure. Some experts also advise withholding metformin immediately prior to major surgery. (Choice A) Calcium channel blockers have no adverse interactions with anesthetic agents and have a modest benefit in reducing ischemia and atrial arrhythmias in patients undergoing noncardiac surgery. They should be continued in the perioperative period. (Choice B) HMG CoA reductase inhibitors (statins) reduce the risk of cardiovascular events, with decreased incidence of myocardial infarction and cardiac death in high-risk patients; they should be continued in patients undergoing surgery. (Choice C) Beta-blockers decrease myocardial oxygen demand and reduce ischemia and arrhythmias in the perioperative period. Acute withdrawal of beta-blockers can lead to significant cardiovascular morbidity; they should be continued in the perioperative period with close monitoring of the heart rate and blood pressure response. (Choice E) Inhaled beta agonists (salmeterol) and anticholinergics (ipratropium) reduce the risk of postoperative pulmonary complications in patients with asthma and chronic obstructive pulmonary disease. They should be continued perioperatively. Educational objective: Selective estrogen receptor modulators, such as raloxifene, are associated with an increased risk of venous thromboembolism and should be discontinued 4 weeks prior to any surgical procedure associated with a moderate to high risk of venous thromboembolism. References: Stopping and restarting medications in the perioperative period. (http://www.ncbi.nlm.nih.gov/pubmed/11565489) The use of raloxifene in osteoporosis treatment. (http://www.ncbi.nlm.nih.gov/pubmed/23521229)

A 58-Year-Old Woman Comes to the Physician for a Preoperative