Understanding Your Medications: Before Anaesthesia

Before your anaesthesia and surgical procedure, it's crucial to understand how your existing medications and any newly prescribed ones will be managed. This involves two categories: your regular medications (those you already take) and additional medications prescribed specifically for your surgical preparation.

Regular Medications: Continuing or Discontinuing?

Many individuals, particularly those with chronic conditions like high blood pressure, heart disease, asthma, or diabetes, take multiple regular medications. Historically, anaesthesiologists often advised patients to discontinue these medications before surgery. However, current practice generally favours continuing most regular medications up until the time of surgery. This approach minimises potential complications arising from abrupt medication withdrawal.

There are, however, specific exceptions that require careful consideration, detailed below.

Special Considerations: Medications Requiring Adjustment

• Antidepressants: Monoamine Oxidase Inhibitors (MAOI's): A specific class of antidepressants, known as MAOI's, carries a risk of serious drug interactions. Combining MAOI's with adrenaline (epinephrine) or pethidine (meperidine) can trigger an overstimulation of the brain and a potentially dangerous rise in blood pressure. This interaction can also occur with certain foods, such as aged cheeses or red wine. If you are taking an MAOI and require anaesthesia, it's essential that you and your primary care physician or psychiatrist arrange for the medication to be discontinued beforehand. In emergency situations where this isn't possible, it's vital to inform your anaesthesiologist so they can avoid administering interacting medications.
• Anticoagulants and Aspirin: These medications are used to thin the blood and reduce the risk of clotting. If you are taking warfarin (Coumadin), you must receive specific instructions from both your anaesthesiologist and surgeon regarding when and how to taper the dose. Individuals who have experienced a stroke or are at risk of one may be taking antiplatelet agents or non-steroidal anti-inflammatory drugs like aspirin, often for heart problems or arthritis. These medications affect how platelets, cells in the bloodstream, stick together during clot formation. Their effects can persist for up to 14 days. While some patients can safely discontinue these medications before surgery, others should not, particularly those with chronic heart disease or a history of stroke. Discontinuing these medications can also exacerbate pain and stiffness in individuals with arthritis who rely on them for symptom management. Consultation with your primary care physician, anaesthesiologist, and surgeon is crucial.
• Diabetic Medications and Insulin: If you manage your blood sugar with oral medications, you should generally avoid taking them on the day of your procedure. Fasting, combined with these medications, can lead to dangerously low blood sugar (hypoglycaemia) while you are under anaesthesia, when you are unable to communicate symptoms. Metformin, a common diabetic medication, has also been linked to a rare but serious condition involving acid buildup in the bloodstream, particularly during procedures involving the heart-lung machine.

For patients taking insulin, careful management is essential. Ideally, diabetic patients should be scheduled as the first case of the day to allow for optimal recovery and resumption of a normal diet. Dosage adjustments may be necessary, with some patients receiving a reduced dose or omitting insulin until they can safely eat or drink again. Blood sugar levels should be checked immediately before surgery and upon arrival in the recovery room. Continuous monitoring during the procedure by the anaesthesiologist may also be implemented.