The management of chronic medications in the perioperative period involves several principles to ensure patient safety and optimal outcomes:
- Obtain a complete medication history and verify accuracy: All clinicians involved in patient care, including surgeons, anesthesiologists, and medical consultants, should review the patient’s medication history. This includes prescription drugs, over-the-counter medications, herbal supplements, and substances such as alcohol, nicotine, and illicit drugs.
- Maintain essential medications: Medications associated with known medical risks if abruptly withdrawn should be continued or tapered when feasible. Intravenous, transdermal, or transmucosal medications can be used if oral intake is impaired. Non-essential medications that increase the risk of complications should be held during the perioperative period.
- Consider potential drug interactions: The numerous medications administered during the perioperative period increase the risk of drug-drug interactions, requiring careful monitoring.
- Recognize altered metabolism and elimination: Medication metabolism and elimination can change during the perioperative period due to factors like altered blood flow and edema, potentially affecting drug efficacy and safety.
- Resume medications postoperatively: Most medications can be resumed once the patient can tolerate oral intake. Exceptions include drugs affecting bleeding or thromboembolic risk, which need careful consideration.
Regarding cardiovascular medications, here are some specific recommendations:
CARDIOVASCULAR MEDICATIONS
- Beta blockers: Continue beta blockers in most cases to maintain stable blood pressure and heart rate. Consider switching to intravenous forms if oral intake is restricted.
- Alpha 2 agonists: Continue alpha 2 agonists if the patient is already on them but avoid initiating them in the perioperative period.
- Calcium channel blockers: Generally, continue calcium channel blockers preoperatively unless contraindicated. Intravenous formulations can be used if oral intake is limited.
- ACE inhibitors and ARBs: Individualize the decision to continue or discontinue based on the patient’s indication, blood pressure, and planned surgery. Generally, continue for patients with heart failure or uncontrolled hypertension.
- Diuretics: Consider holding diuretics on the morning of surgery for patients on chronic therapy. For heart failure patients, continue diuretics if volume status is stable.
- Other cardiovascular medications: Discontinue niacin, fibric acid derivatives, bile sequestrants, and ezetimibe temporarily before surgery. Continue digoxin perioperatively, especially for patients with atrial fibrillation.Gastrointestinal Agents – H2 Blockers and Proton Pump Inhibitors:
- These medications may provide benefits by reducing the risk of stress-related mucosal damage and aspiration-induced lung injury.
- Both H2 blockers and proton pump inhibitors decrease gastric volume and raise gastric fluid pH, lowering the risk of chemical pneumonitis from aspiration.
- Continue these medications perioperatively due to potential benefits and lack of contraindications.
- If patients can’t take oral medications for an extended period, switch to intravenous forms.
- Proton pump inhibitors have been associated with an increased risk of Clostridioides difficile infection.
Pulmonary Agents:
- Inhaled beta agonists and anticholinergics should be continued perioperatively for patients with obstructive pulmonary disease to reduce postoperative pulmonary complications.
- Theophylline medications should be discontinued the evening before surgery due to potential interactions with other perioperative medications and its risk of arrhythmias and neurotoxicity.
- Glucocorticoids, both inhaled and systemic, should be continued during the perioperative period, especially in patients with pulmonary disease.
- Leukotriene inhibitors like zafirlukast and montelukast can be continued on the morning of surgery and resumed once the patient can tolerate oral medications.
Endocrine Agents:
- Perioperative management of glucocorticoids depends on the patient’s medical history and need for stress dosing. They are generally continued perioperatively.
- For diabetic medications, follow guidelines for perioperative blood glucose management in patients with diabetes.
- Continue oral contraceptives perioperatively with appropriate thromboprophylaxis. Consider discontinuation in high-risk surgery.
- Continue postmenopausal hormone therapy based on the VTE risk of the procedure and patient preference.
- For selective estrogen receptor modulators (SERMs) like tamoxifen and raloxifene, consider discontinuation for surgeries with a high risk of VTE based on the specific medication and indication.
- Drugs used for thyroid disease should generally be continued perioperatively. Thyroxine (T4) has a long half-life and can be given parenterally if needed. Antithyroid medications may require individualized decisions based on the patient’s history.
Tricyclic and Tetracyclic Antidepressants:
- These antidepressants inhibit the reuptake of norepinephrine and serotonin.
- They possess anticholinergic, antihistaminic, and alpha-1 blocking properties.
- They can delay gastric emptying, prolong the QTc interval, and may increase the risk of arrhythmias when combined with certain anesthetics or sympathomimetic agents.
- Abrupt withdrawal should be avoided due to potential withdrawal symptoms.
- Recommendations vary, but generally, continuing these agents in the perioperative period is advised.
- If discontinuation is considered, it should be done gradually based on the patient’s depression severity.
Selective Serotonin Reuptake Inhibitors (SSRIs):
- SSRIs may increase bleeding risk and transfusion need during surgery.
- Perioperative bleeding risk varies based on surgery type.
- In most cases, SSRIs are recommended to be continued due to the risk of exacerbating mental disorders.
- In high-risk bleeding surgeries, SSRIs might be discontinued with careful consideration.
Monoamine Oxidase Inhibitors (MAOIs):
- Nonselective irreversible MAOIs are used for refractory mood disorders.
- They have complex interactions with sympathomimetic agents and opioid metabolism.
- A “Type I” reaction can occur with serotonin syndrome when combined with certain drugs.
- A “Type II” reaction can lead to narcotic accumulation and respiratory depression.
- Close collaboration with anesthesiologists and psychiatrists is necessary to decide whether to continue or discontinue MAOIs.
Mood Stabilizing Agents (Lithium and Valproate):
- Lithium has physiological effects that can affect perioperative management.
- Valproate is another mood stabilizer.
- Recommendations vary, but generally, continuation with increased monitoring is advised.
- Serum levels of these agents should be monitored.
Antipsychotics:
- Antipsychotics control psychoses and prevent delirium in certain cases.
- They may prolong the QT interval and cause arrhythmias when combined with specific drugs.
- Recommendations vary, but they should be used cautiously and may need to be withheld in certain situations.
Antianxiety Agents:
- Abrupt withdrawal of chronic benzodiazepines can lead to excitatory states.
- Short-term benzodiazepine use for anxiety relief is generally safe in the perioperative period.
- Buspirone is considered safe and has slow onset.
- Recommendations vary, but chronic use should generally be continued.
Psychostimulants:
- Psychostimulants used for ADHD can increase the risk of hypertension and arrhythmias.
- They may interact with perioperative medications.
- Generally, psychostimulants can be temporarily withheld on the day of surgery.
Bisphosphonates for Osteoporosis/Osteopenia:
- Bisphosphonates, especially in malignancy, have been associated with a low risk of osteonecrosis of the jaw during dental surgery.
- Discontinuation of bisphosphonates for weeks or months before surgery has not shown a decrease in the risk of osteonecrosis.
- Bisphosphonates should be withheld only on the morning of surgery when taken with water, and the patient is required to remain upright.
- For patients at very high risk, delaying surgery for two months may be considered, but such cases are rare.
Aspirin:
- Aspirin irreversibly inhibits platelet cyclooxygenase and can increase intraoperative bleeding risk.
- The perioperative benefits and risks of aspirin depend on the patient’s indication and planned surgery.
- For certain surgeries (e.g., CABG, vascular surgery), continuing aspirin is recommended to prevent vascular complications.
- For other surgeries, the decision to continue or discontinue aspirin should be individualized based on the patient’s condition and the surgical procedure.
- Aspirin can be safely continued in minor dental surgery and dermatologic procedures.
- Guidelines suggest that aspirin does not interfere significantly with neuraxial blocks.
Other Antiplatelet Agents:
- Dual antiplatelet therapy with agents like clopidogrel is common for preventing stent thrombosis after coronary interventions.
- Dipyridamole is used in patients with past stroke or transient ischemic attack (TIA) and should be discontinued at least two days before surgery.
- Cilostazol, used for claudication symptoms, should be discontinued several days before elective surgery.
Nonsteroidal Anti-Inflammatory Drugs (NSAIDs):
- NSAIDs, including selective COX-2 inhibitors, inhibit platelet function and increase bleeding risk.
- Discontinuing NSAIDs before surgery is generally recommended to manage bleeding risk.
- The elimination half-life of NSAIDs does not necessarily correlate with platelet function normalization.
- Intravenous formulations of NSAIDs like ketorolac and ibuprofen are available for short-term pain management when oral administration is not possible.
- Non-acetylated NSAIDs like diflunisal and salsalate can be considered for pain control in the perioperative period.
Naltrexone:
- Naltrexone is an opioid receptor antagonist used to manage opioid addiction and alcoholism.
- Chronic naltrexone use can increase opioid receptor concentration, leading to an exaggerated response to opioids in acute pain situations.
- Naltrexone should be discontinued before surgery.
- Multimodal pain management approaches, including local anesthetics, NSAIDs, acetaminophen, etc., are recommended.
- Opioids with higher affinity for the mu receptor are advised for postoperative acute pain.
- A “reverse ladder” approach, combining nonopioid pain control with resumption of naltrexone, can be considered postoperatively.
Gout Therapy:
- Surgery can trigger acute gouty arthropathy.
- It’s recommended to hold colchicine on the morning of surgery and resume when oral intake is possible.
- Allopurinol can be continued.
- No parenteral substitutions are available for allopurinol or probenecid.
- Acute gout flare in a postoperative patient can be managed with intraarticular or systemic steroids.
Medications for Benign Prostatic Hypertrophy:
- Alpha-1-antagonists (e.g., terazosin, doxazosin, tamsulosin, alfuzosin) can cause intraoperative floppy iris syndrome (IFIS) during cataract surgery.
- Patients should be asked about alpha-1-antagonist use during preoperative evaluation.
- Discontinuing these agents may not significantly reduce the risk of IFIS.
- Surgeons should be informed if the patient is on alpha-1-antagonists to manage the condition during surgery.
Herbal Medications and Perioperative Risk:
- Herbal medications are commonly used but can have adverse effects during the perioperative period, including clotting abnormalities and interactions with anesthetics.
- Patients often do not disclose their herbal medication use, so clinicians should ask specifically about it during preoperative evaluations.
- There’s no evidence that herbal medications improve surgical outcomes, and they might increase perioperative risks.
- Due to concerns about purity and potential interactions, it’s recommended to stop herbal agents at least one week before surgery.
- Review of Commonly Used Herbal Remedies:
- Ephedra (mahuang): May increase the risk of heart attack and stroke, should be discontinued at least 24 hours before surgery.
- Garlic: May increase bleeding risk, should be discontinued at least seven days before surgery.
- Ginkgo: May increase bleeding risk, should be discontinued at least 36 hours before surgery.
- Ginseng: Lowers blood sugar and may increase bleeding risk, should be discontinued at least seven days before surgery.
- Kava: May enhance sedative effects of anesthetics, should be discontinued at least 24 hours before surgery; associated with fatal hepatotoxicity.
- St. John’s wort: Can diminish the effects of several drugs by inducing cytochrome P450 enzymes, should be discontinued at least five days before surgery.
- Valerian: May enhance sedative effects of anesthetics and cause benzodiazepine-like withdrawal; ideally tapered weeks before surgery.
- Echinacea: Associated with allergic reactions and immune stimulation; no specific data on preoperative discontinuation.
