Medication Advice

This group includes anticoagulants such as warfarin, apixaban (Eliquis), rivaroxaban (Xarelto) and dabigatran (Pradaxa), and antiplatelet medications such as clopidogrel (Plavix, Iscover), ticagrelor (Brilinta) and aspirin.

Whether a blood thinner is stopped, continued, or bridged with another medication is a careful balance between your bleeding risk during surgery and the reason you take it — and the plan is made for you individually by your surgeon, anaesthetist and, where relevant, your cardiologist or haematologist. Some are stopped several days beforehand; some are continued. It is especially important that we know if you have a coronary stent, atrial fibrillation, a mechanical heart valve or a history of blood clots. If your surgery is approaching and nobody has told you what to do with your blood thinner, do not guess — contact your surgeon’s rooms or us immediately.

Insulin and most diabetes tablets: you will be given an individual plan — doses are commonly reduced or withheld while you are fasting, and patients with diabetes are usually scheduled early on the operating list. Make sure you receive specific advice about your insulin: as a general rule, short-acting (mealtime) insulin is not taken on the morning of morning surgery while you are fasting. Bring all your diabetes medications and your glucose monitor to hospital.

SGLT2 inhibitors — the “flozins” (empagliflozin/Jardiance, dapagliflozin/Forxiga, ertugliflozin/Steglatro, including combination tablets): around surgery and fasting these carry a small risk of a serious chemical imbalance (a form of ketoacidosis) that can occur even when your blood sugar readings look normal. For minor procedures with a short fast they are often continued; for major surgery, or where a longer period without eating is expected, they are usually stopped 48 hours before surgery (4 days for ertugliflozin). Your health — particularly heart failure or kidney disease — can change this plan, so always follow the specific instructions you are given, and do not restart until you are eating and drinking normally, as advised. After surgery, seek help promptly if you develop nausea, vomiting, abdominal pain, unusual tiredness or rapid breathing.

GLP-1 medications used for diabetes (Ozempic, Mounjaro, Trulicity, Victoza, Rybelsus): keep taking them as normal, but your fasting preparation changes — open the section below: Special fasting preparation for GLP-1 medications.

GLP-1 injections used for weight loss — Wegovy, Saxenda, Mounjaro and similar — work partly by slowing the emptying of your stomach. That means a standard overnight fast may not leave your stomach empty, which is a safety risk during anaesthesia. Keep taking your medication as you normally would unless specifically told otherwise — it is the food and fluid preparation that changes, and it starts a full day early. Open the section below, Special fasting preparation for GLP-1 medications, and please make sure we know you are on one of these medications well before your surgery date.

ANZCA’s updated guidance explicitly recommends continuing your GLP-1/GIP medication as normal and following a 24-hour clear-fluid diet before your procedure — that is exactly what the steps below describe.

The whole day before your procedure: no solid food at all — drink only clear fluids, meaning liquids you can see through with no particles or milk in them. You can drink these freely, and staying well hydrated is encouraged.

• Fine to have: water, black tea or black coffee, clear apple juice, lemonade and other clear soft drinks, clear cordial, electrolyte or sports drinks, special pre-operative carbohydrate drinks, clear broth (nothing solid in it), jelly, and icy poles.
• Not allowed: anything containing milk, yoghurt drinks, ice cream, cloudy or pulpy juices (such as orange or prune juice), fibre supplements, and alcohol.

The day of your procedure: no solid food. Unless the hospital gives you different times:

• Morning procedure: stop all clear fluids except water at midnight. From midnight, sip small amounts of water — up to about half a cup (125 ml) each hour — until 6:00am. After 6:00am, nothing at all.
• Afternoon procedure: clear fluids until 6:00am, then small sips of water only — up to about half a cup (125 ml) each hour — until 11:00am. After 11:00am, nothing at all.

If you realise you haven’t followed these instructions: don’t panic, and don’t assume your procedure is cancelled. Pick up the preparation timeline from wherever you are now, and phone the hospital or your surgeon’s rooms as soon as possible to tell them exactly what you had and when. In many cases the procedure can still go ahead.

Continue as normal, including on the morning of surgery (with a small sip of water): most blood pressure and heart medications. Beta blockers — names ending in “-lol”, such as metoprolol or atenolol — in particular should not be missed.

Often withheld on the morning of surgery: ACE inhibitors (names ending in “-pril”, such as perindopril or ramipril), angiotensin receptor blockers (ending in “-sartan”, such as irbesartan or candesartan), and fluid tablets (diuretics). As always, the instructions given to you for your operation take priority — if you’re not sure, ask.

Herbal and over-the-counter supplements (such as fish oil, ginkgo, garlic or St John’s Wort) can affect bleeding and anaesthetic medications — list them all on your health questionnaire, as some are stopped in the week or two before surgery. Hormone therapy and the contraceptive pill may need discussion for surgery with a higher clot risk — your surgeon will advise. And please be straightforward about alcohol and recreational drug use: it changes how anaesthetic medications behave, and the information stays confidential.