Your usual medicines may need to be adjusted before surgery to keep you safe. Always bring your medicines (or a complete list) to hospital, including tablets, inhalers, patches, and injections. Below is a guide to common medicines.
If you are unsure about any drug, ask!
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ACE Inhibitors and ARBs
Examples: perindopril (Coversyl®), ramipril (Tritace®), lisinopril (Zestril®), irbesartan (Avapro®), valsartan (Diovan®), candesartan (Atacand®), telmisartan (Micardis®), losartan (Cozaar®).
Instruction: Withhold for 24 hours before surgery (do not take on the morning of surgery).
Beta-blockers
Examples: atenolol (Tenormin®), metoprolol (Betaloc®, Lopresor®), bisoprolol (Bicor®), propranolol (Inderal®).
Instruction: Continue as normal, including the morning of surgery.
Calcium channel blockers
Examples: amlodipine (Norvasc®), diltiazem (Cardizem®), verapamil (Isoptin®).
Instruction: Continue as normal.
Diuretics
Examples: frusemide (Lasix®), hydrochlorothiazide, indapamide (Natrilix®), spironolactone (Aldactone®).
Instruction: Withold on the morning of surgery to reduce dehydration/low blood pressure.
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Warfarin (Coumadin®, Marevan®)
Usually stopped 5 days before surgery. May need “bridging” with injections.
Direct Oral Anticoagulants (DOACs)
Examples: apixaban (Eliquis®), rivaroxaban (Xarelto®), dabigatran (Pradaxa®), edoxaban (Lixiana®).
Usually stopped 2–3 days before surgery (longer if kidney function is reduced).
Antiplatelets
Examples: clopidogrel (Plavix®), ticagrelor (Brilinta®), prasugrel (Effient®).
Usually stopped 5–7 days before surgery.
Aspirin (Cartia®, Astrix®) → Continued
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Insulin
Long-acting (Optisulin®, Toujeo®): usually take half dose night before and morning of surgery.
Mixed/intermediate insulins (Humulin®, Protaphane®, Novomix®): reduced or withheld if fasting.
Short-acting (Novorapid®, Humalog®, Actrapid®): withheld if fasting.
Insulin pumps: usually continue basal rate (sometimes reduced).
Tablets
Metformin (Diabex®, Glucophage®): withhold on the day of surgery.
SGLT2 inhibitors (Forxiga®, Jardiance®, Invokana®): stop 3 days before surgery.
Sulfonylureas (Diamicron®, Minidiab®, Amaryl®): stop on day of surgery.
DPP-4 inhibitors (Januvia®, Galvus®, Trajenta®): stop on day of surgery.
Thiazolidinediones (Actos®): stop on day of surgery.
Injectables
GLP-1 agonists (Mounjaro®, Ozempic®, Trulicity®, Rybelsus®, Byetta®, Victoza®): https://static1.squarespace.com/static/68afe51edcc7b51a5990b8ca/t/68b4ecb278ba0f7419ed4dde/1756687538069/PIL+Guidance+for+Patients+Taking+GLP-1RA+or+GLP-1RA-GIPRA+Medications+Before+Surgery.pdf
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Statins
Examples: atorvastatin (Lipitor®), rosuvastatin (Crestor®), simvastatin (Zocor®), pravastatin (Pravachol®).
Instruction: Continue as normal.
Other cholesterol-lowering drugs
Ezetimibe (Ezetrol®), fenofibrate (Lipanthyl®). → Continue.
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Examples: sertraline (Zoloft®), escitalopram (Lexapro®), venlafaxine (Efexor®), amitriptyline (Endep®).
Instruction: Continue.
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Examples: valproate (Epilim®), carbamazepine (Tegretol®), levetiracetam (Keppra®).
Instruction: Continue.
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Examples: Ventolin®, Seretide®, Spiriva®.
Instruction: Continue and bring them to hospital.
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Examples: prednisone, dexmethasone, hydrocortisone.
Instruction: Do not stop suddenly. You may need extra “stress doses” during surgery.
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Paracetamol: continue as normal.
Anti-inflammatories (NSAIDs): (Nurofen®, Voltaren®, Mobic®) - stopped before surgery due to bleeding/kidney risk.
Opioids (Endone®, Targin®, Tramadol®): continue if prescribed.
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Fish oil, vitamin E, garlic, ginkgo, ginseng, St John’s Wort: stop at least 7 days before surgery.
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If you are taking Ozempic, Wegovy, Mounjaro, Trulicity or similar medications before surgery, you will need to follow special fasting rules.
- 24–6 hours before surgery: clear fluids only.
- 6–2 hours before: water only (max 200 ml per hr).
- 2 hours before: nothing by mouth.
Clear fluids include water, black tea/coffee (no milk), clear apple juice, electrolyte drinks, or clear broth. Avoid milk, smoothies, protein shakes, creamy soups, or juices with pulp.
If you did not follow these instructions, please tell me - your surgery may be delayed or modified.
Some conditions (e.g. gastroparesis, Parkinson’s, bowel problems) may also slow stomach emptying, even with correct fasting. Please let your me know.