Current Clinical Pharmacology - Volume 12, Issue 3, 2017

Background: As the prevalence of hypertension continues to increase, physicians routinely encounter patients preoperatively receiving one or more cardiovascular medications to manage hypertension. Thus, the physician's knowledge of perioperative antihypertensive medication management is crucial to ensure patient safety. Objective: We discuss the decisions to continue or stop antihypertensive medications to reduce the risk of perioperative complications. Method: We conducted a review of the original research studies, review articles, and editorials present on PubMed within the past 60 years. The authors included peer-reviewed articles that they deemed relevant to current practice. Search terms of perioperative surgical home, preoperative medication instruction, surgery, and perioperative management were used in combination with the key words α-agonist, antihypertensive, β-blocker, calcium-channel blocker, diuretic, hypertension, renin-angiotensin-aldosterone system inhibitor, and vasodilator. The reference lists of each selected article were also reviewed for additional sources of information. Results: The number of articles about perioperative management of antihypertension medications increased in more recent years. Evidence showed clear support of the continuation or withholding of most medications. However, no clear recommendation was found on the continuation of reninangiotensin- aldosterone system inhibitors in the perioperative period. Conclusion: Current evidence supports the perioperative continuation of β-blockers, calciumchannel blockers, and α-2 agonists. However, diuretics should be discontinued on the day of the surgery and resumed in the postoperative period. Debates persist about the continuation of reninangiotensin- aldosterone system inhibitors.

Background: Antiarrhythmic medications are an important tool in preventing recurrence of intraoperative and postoperative arrhythmias. Objective: To review current literature and recommendations for perioperative management of antiarrhythmic medications. Methods: Literature review is presented along with the pharmacology of antiarrhythmics. Results: Antiarrhythmic medications should be continued perioperatively for the prevention of arrhythmias intra- and postoperatively. However, beta blockers have had controversies regarding their perioperative safety profile. Conclusion: Continuation of antiarrhythmic medications is safe perioperatively. However, initiation of beta blockers should be patient-tailored and titrated to a target heart rate in advance surgery.

Background: The prevalence of anticoagulant use has increased in the United States. Medical providers have the responsibility to explain to patients the management of anticoagulant regimens before an invasive procedure. The pharmacologic characteristics of these medications, specifically their half-lives, are important in timing an interruption of anticoagulant therapy. Objective: The authors review the current guidelines and recommendations for therapeutic interruption of anticoagulants and the involved pharmacologic factors. Methods: Guidelines and other literature are summarized with discussion on the pharmacology of each medication. Recommendations on how and when to provide bridging for anticoagulants are discussed. Newer oral anticoagulants also are discussed, along with interruption recommendations. Results: Literature reveals a conservative approach for using bridging when anticoagulation is interrupted because of higher risks of bleeding. Caution is advised when resuming anticoagulant therapy when neuraxial anesthesia is used. Conclusion: Perioperative healthcare providers need to balance risks and benefits of anticoagulant therapy with its interruption preoperatively.

Background: Coronary artery disease is a common comorbidity encountered during the perioperative period. Whether patients are scheduled for cardiac or noncardiac surgery, this cardiovascular disease must be addressed in the preoperative period to decrease the accompanying risks and potential postoperative problems. Lipid-lowering medications are often used to treat hyperlipidemia, a risk factor for the development of atherosclerosis and coronary artery disease. Objective: To discuss the medications most commonly used to treat hyperlipidemia and to describe strategies for handling these treatment regimens in the perioperative period. Method: An online search of studies and review articles was conducted through PubMed and Medline that addressed pharmacology and perioperative management of hyperlipidemia medications. Results: Statins are the most commonly prescribed lipid-lowering agents, with benefits that extend beyond correcting lipid levels. However, statins can have clinically significant adverse effects that may necessitate the use of other lipid-lowering medications with different mechanisms of action. Alternative medications such as nicotinic acid and omega-3 fatty acids should be withheld in the preoperative period because these agents have been associated with hypotension and increased bleeding. Conclusion: Clinicians must be familiar with the various lipid-lowering agents because it is very likely they will encounter such medications during preoperative visits.

Background: Given the prevalence of diabetes mellitus in modern society, health care providers are frequently tasked with managing glucose control in the perioperative period. When determining perioperative diabetes management, the clinician must balance the need to maintain relative euglycemia at the time of surgery with preventing hypoglycemia or hyperglycemia in a fasting surgical patient. This balance requires an understanding of the pharmacology of these medications, the type of surgery, and the patient's degree of diabetic control. Objective: We discuss the various medications used in the treatment of diabetes mellitus and the current recommendations regarding perioperative care. Method: A review of the current literature present on Pubmed and Medline was conducted between the years 2000-2016. The reference lists of each selected article were also reviewed for additional sources of information. Conclusion: Perioperative control of blood glucose levels is associated with less morbidity and improved surgical outcomes in patients with and without DM. Preoperatively, clinicians need to thoughtfully adjust diabetic medications on the basis of patient comorbidities, the duration of the fasting period, and the duration of surgery. Intraoperative and postoperative strategies typically use insulin to maintain blood glucose levels in the range of 80 to 180 mg/dL.

Background: Pain continues to be the most common medical concern, and perioperative health care providers are encountering increasing numbers of patients with chronic pain conditions. It is important to have a clear understanding of how long-term use of pain medications impacts anesthesia during the intraoperative and postoperative periods. Objective: To review common medications used to treat chronic pain and summarize current recommendations regarding perioperative care. Method: We reviewed the literature by searching PubMed and Google Scholar for articles from 2000-2016. The search strategy included searching for the various classes of pain medications and including the terms perioperative, anesthesiology, and recommendations. We also reviewed the reference lists of each article to identify other relevant sources regarding the perioperative management of pain medications. Results: After the literature review, we were able to establish the pharmacology, anesthetic interactions, and recommendations for management of each of the common classes of pain medication. Conclusion: Management of postoperative pain is an important concern for all perioperative health care providers. Although most pain medications should be continued in the perioperative period, it is important to preoperatively discontinue those that antagonize pain receptors to avoid significant postoperative morbidities associated with poorly managed pain.

Background: Psychotropic medications are being used increasingly as analgesics and for other off-label indications for patients with and without psychiatric conditions. While the pharmacology of most of these drugs is now known, their interaction with anesthetic drugs and implications of regular use are still relatively unclear. Objective: We discuss the pharmacology, side effects, and potential medication interactions with anesthetic agents of various commonly prescribed psychotropic medications and the current recommendations regarding the continuation of these medications during the patients' perioperative care. Method: A review of the current literature present on PubMed and Medline was conducted between the years 2000-2016. The reference lists of each selected article were also reviewed for additional sources of information. Conclusion: Psychotropic medications can be broadly divided into classes, which include antidepressants, antipsychotics, anxiolytics, mood stabilizers, and stimulants. Although most evidence suggests the continuation of these medications in the perioperative period, it is still important to determine how psychotropic medications interact with routinely used anesthetic agents and which medications should be continued and which should not be continued on an individualized basis for each patient.

Background: Optimizing a patient for surgery is a central goal during the preoperative period. Patients with common neurologic disorders, such as Alzheimer's disease, epilepsy, Parkinson's disease, and multiple sclerosis may require special attention in the perioperative management of their neurologic medications. Objective: This review aims to organize the most current recommendations for neurologic medication management during the perioperative period to minimize the risk of postoperative neurologic decline. Methods: A review of current literature present on PubMed and Medline of peer-reviewed research papers was conducted. The quality of the papers was assessed according to their research methodology and many of their sources were further analyzed in the same manner. A focused review question for each disease type was used, and, at times, inclusion and exclusion criteria were applied. Results: Manuscripts covered a wide range of medical subspecialties with the most common sources being anesthetic, neurologic, and pharmacologic journals. Conclusion: The systemic inflammation that occurs in the perioperative period is detrimental to a patient's neurologic status. It is important to recognize that the proper management of neurologic medications can limit the negative effects of these stresses on a patient. Most medications appear safe to continue until the morning of surgery. Consultation with a neurologist regarding continuation of specific medications may be necessary to further ensure patient safety.

Background: Pulmonary conditions such as asthma and chronic obstructive pulmonary disease (COPD) are common conditions that warrant special consideration in the perioperative period. When these patients undergo surgical interventions, they have risk of complications such as bronchospasm, hypoxia, and even postoperative respiratory failure that warrant unplanned intensive care unit admission. Thus, clinicians must be familiar with pulmonary medication regimens that are critical for maintaining stable homeostasis of these chronic conditions. Objective: To discuss the medications most commonly used to treat pulmonary conditions and to describe strategies for handling these treatment regimens in the perioperative period. Method: We conducted an online search of studies and review articles through PubMed and Medline that addressed pharmacology and perioperative management of pulmonary medications, with an emphasis on those treating patients with asthma or COPD. Results: Long-term medications for pulmonary disease are used to slow the progression of these conditions and reduce the occurrence of acute exacerbations. As such, these medications should be continued in the perioperative period. If the medications include oral corticosteroids or high-dose inhaled corticosteroids, stress-dose corticosteroid supplementation may be warranted to avoid adrenal insufficiency. Inhaled medications can be delivered through the anesthetic circuit, and some agents may be used to treat exacerbations during surgery. Conclusion: Patients with chronic pulmonary conditions have risk of perioperative complications. Their pulmonary treatment regimens should be maintained in the perioperative period to reduce the risk of such complications.

Background: No clear guideline exists for the management of female hormone therapy in the perioperative period. Besides oral contraceptives (OCPs), hormone medications have been prescribed to treat cancer, osteoporosis, and menopausal symptoms. Since the introduction of OCPs in the 1960s, the thromboembolic risk associated with these medications has been studied and alterations have been made in the hormone content. The continuation of hormone therapy in the perioperative period and its possible interactions with commonly used anesthetic agents are important information for all perioperative health care providers. Objective: A review was done on the current guideline and available literature for the mechanisms of action and perioperative management of OCPs, hormone replacement therapy (HRT), and antineoplastic hormonal modulators. Method: Available guidelines and literature were reviewed and summarized. Results: Based on the available literature, no definite guidelines have been established for perioperative management of OCPs and HRT. However, manufacturers have recommended that these medications should be held perioperatively. Other antineoplastic hormonal modulators have increased the risk of venous thromboembolism and have perioperative implications that should be discussed with the prescribing physicians and addressed with the patient. Conclusion: Until additional studies are performed, the risks and benefits must be weighed on an individual basis with consideration of prophylaxis when a decision is made to continue these medications in the perioperative period. Part of this decision making includes the risk of fetal harm in an unwanted pregnancy in preparation for nonobstetric surgery versus an increased risk of venous thromboembolism.

Background: A considerable portion of the US population uses herbal supplements on a daily basis for their various proposed beneficial effects. However, the over-the-counter nature of these medications and lack of knowledge of adverse effect profiles can have unexpected serious impact on the perioperative course. The growing list of supplements presents a pharmacologic conundrum to the anesthesiologist. Objective: The study aimed to compile a comprehensive list of vitamins, herbals, and supplements used commonly by patients, describe the risks associated with them, and identify recommendations for perioperative management. Method: The current literature on PubMed and Medline was reviewed for the years 2000 through 2016. The reference lists of each selected article were also reviewed for additional sources of information. Results: The review identified 23 herbals and supplements that are commonly used and their perioperative considerations. Conclusion: The management of herbals and supplements is an issue for the anesthesiologist. Although it would be prudent to stop the use of most substances a week or more preoperatively, the perioperative physician must be wary of the potential for withdrawal.