Medicines to review before anaesthesia

Do not stop or change medicines without your clinician’s instructions. This page provides typical patterns and why timing matters.

High-impact categories

1) Anticoagulants / “blood thinners”

These drugs reduce clotting and can increase bleeding risk during surgery. They are particularly important when planning neuraxial anaesthesia (spinal/epidural) or deep plexus blocks, because a spinal/epidural hematoma—while rare—can be catastrophic.

Warfarin (INR-based management; sometimes bridging)
DOACs (apixaban, rivaroxaban, edoxaban, dabigatran): often held for a period (commonly ~72h for several DOACs; longer for dabigatran with renal impairment) when neuraxial techniques are planned
Antiplatelets (aspirin, clopidogrel, prasugrel, ticagrelor): vary by stent history and surgical bleeding risk

Regional/neuraxial anticoagulation guidance is detailed and situation-specific; see clinician guidelines such as ASRA recommendations.

2) Diabetes medicines: SGLT2 inhibitors

SGLT2 inhibitors can increase risk of euglycemic diabetic ketoacidosis (eDKA) around surgery, especially with fasting or illness. Multiple guidance documents recommend stopping most SGLT2 inhibitors about 3 days before scheduled surgery (and 4 days for ertugliflozin).

3) GLP‑1 receptor agonists

GLP‑1 drugs may delay gastric emptying and raise aspiration concern under anaesthesia/deep sedation. Guidance has evolved toward individualized risk assessment, with some patients able to continue. Inform your anaesthesia team early, especially if you have GI symptoms.

4) Blood pressure medicines

Beta blockers: usually continued (stopping abruptly can be harmful)
ACE inhibitors/ARBs: practice varies; some teams hold on the morning of surgery due to hypotension risk
Diuretics: may be adjusted depending on dehydration risk

5) Statins and most chronic cardiac medicines

Statins and most long-term cardiac drugs are commonly continued unless your clinician advises otherwise.

6) Opioids, sedatives, alcohol, and recreational drugs

Chronic opioid use increases postoperative pain needs and respiratory depression risk (especially with OSA/obesity/older age).
Benzodiazepines and alcohol can interact with sedatives; withdrawal risk is also relevant.
Stimulants and illicit drugs can increase arrhythmia and blood pressure volatility.