Drugs & Anesthesia
Drugs stop/continue before/during Surgery
(A)Drugs to be stopped before surgery:
1. Oral hypoglycemic
If Minor surgery – Omit morning dose
If Major surgery – Switch to insulin 48hrs before, and then omit morning dose of
insulin on day of surgery
Estrogen containing pills to be stopped 4 weeks before surgery. Stopped for prevention of DVT (Progesterone only pills can be continued)
3. MAO inhibitors
– discontinue 2-3 weeks before Surgery
(Hypertensive crisis can occur when monoamine oxidase inhibitors are used with sympathomimetics)
(Risk of interaction with perioperative Meperidine, Ephedrine & Opioids)
4. Oral Anticoagulant
Stop 1 week before and switch to low molecular weight heparin (which is stopped 1 day before surgery)
Heparin/low molecular weight heparin: The last treatment dose should be given no less than 24 hours before the operation. The last prophylactic dose should be given no less than 12 hours before the operation
– stop 5 – 7 days before
6. Lithium (psychiatric drug)
– stop 48 – 72 hrs before.
(May cause electrolyte disturbances and reduced renal function can precipitate lithium toxicity)
(Antipsychotics can potentiate arrhythmias and enhance hypotension due to Alpha-1 receptor blockade)
7. ACE Inhibitors &
(Omitted on the morning of the operation, where taken in the morning, or from the evening before the operation if taken in the evening. If taken twice daily, both evening and morning doses should be omitted)
(7 & 8: hold one dose before surgery, to reduces risk of immediate post-induction hypotension particularly with hypovolemia)
Note: Smoking should be stopped 6 weeks before surgery. Even if not stopped then, it will still benefit if stopped 12 hrs before surgery.
(B)Drugs that can be continued.
1- Anti-parkinson medications (Levodopa)
2- Psychiatric medications
3- Cardiovascular Drugs: AntiHypertensive (except ACE inhibitors, ARBs & diuretics) AntiAnginals (except Aspirin) & Antiarrhythmic drugs.
4- AntiThyroid drugs.
5- Progesterone (only pills can be continued)