Before EGD or colonoscopy, use this medication guide: blood thinners, diabetes meds, stomach drugs, and supplements – what to pause, what to take, and when to restart.
Answer Box:
Don’t change prescription drugs without a plan. Anticoagulants/antiplatelets require individualized instructions; diabetes meds often need dose/timing changes; iron/bismuth/charcoal are usually held. Bring an up-to-date med list and ask when to resume.
Why Meds Matter for GI Procedures
Every medication you take can affect the safety, clarity, and outcome of an endoscopic procedure. Blood thinners increase the risk of bleeding during polyp removal; certain diabetes drugs raise the chance of hypoglycemia while fasting; and some stomach agents, like iron or bismuth, can darken the bowel wall, obscuring visibility. Sedation adds another layer, since many drugs, especially sleep aids, herbal relaxants, or alcohol, can potentiate anesthetic effects and complicate airway management. Even vitamins and “wellness” supplements may alter clotting or blood pressure.
That’s why gastroenterologists emphasize an individualized medication review before every EGD or colonoscopy. Don’t adjust anything on your own-each change must be coordinated with your care team. (For the diet and timing component, see Colonoscopy Prep.)
Anticoagulants & Antiplatelets
These are among the most complex medications to manage before an endoscopic procedure. The goal is to balance bleeding risk during intervention with the danger of clotting if therapy is paused for too long. Every decision must involve the prescribing specialist, especially for patients with cardiac or thromboembolic conditions.
Who Needs Bridging vs Who Doesn’t
“Bridging” means temporarily switching from a long-acting anticoagulant (like warfarin) to a short-acting one (like low-molecular-weight heparin). It’s reserved for patients at high risk of thrombosis-those with mechanical heart valves, recent venous thromboembolism, or atrial fibrillation with a CHADS-VASc score ?5. Most others can safely pause their anticoagulant for several days without bridging. Direct oral anticoagulants (DOACs) such as apixaban, rivaroxaban, dabigatran, and edoxaban are typically withheld for 2-3 days before the exam, depending on kidney function. Warfarin is stopped about 5 days in advance, with an INR check prior to procedure.
High- vs Low-Bleed-Risk Procedures
The level of intervention determines how far to hold therapy.
Low-risk procedures include diagnostic EGD, colonoscopy with biopsy, or esophageal dilation-these rarely require interruption of low-dose aspirin.
High-risk procedures are polypectomy, sphincterotomy, or endoscopic mucosal resection. These demand stricter control.
For antiplatelet agents such as clopidogrel or prasugrel, clinicians usually stop them 5-7 days before high-risk procedures. Aspirin is generally continued unless bleeding risk outweighs benefit.
Resumption Timing
After uncomplicated, low-risk endoscopy, most patients can resume anticoagulants within 24 hours. After high-risk interventions, resumption is delayed 48-72 hours to monitor for post-procedural bleeding.
Restart only when approved by your gastroenterologist or cardiologist, especially if you’re on dual therapy (e.g., aspirin + clopidogrel). Always confirm exact timing before discharge. Properly cordinated management ensures both a safe procedure and stable cardiac protection, minimizing the chance of either hemorrhage or thrombosis.
Diabetes Medications
Fasting, bowel prep, and sedation can all shift glucose control. The goals are avoid hypoglycemia, prevent dehydration/ketosis, and keep the plan simple. Coordinate changes with your diabetes clinician, and align timing with the procedure-day schedule from Colonoscopy Prep.
Basal Insulin
- Night before: take ~50-80% of your usual dose (individualize for recurrent lows or CKD).
- Morning of procedure (if fasting): many patients take 50% of usual basal; others on ultra-long degludec may skip or reduce depending on prior glucose trends.
- Check glucose on waking and again on arrival. Aim for 100-180 mg/dL (5.6-10 mmol/L).
Prandial / Correction Insulin (rapid-acting: lispro, aspart, glulisine)
- If no breakfast: skip mealtime bolus.
Correction doses can be used conservatively for readings >180 mg/dL per your usual sensitivity factor. Resume normal bolus with the first post-procedure meal.
Oral & Injectable Non-Insulin Agents
- Metformin: hold the morning of the procedure; restart with your first meal.
- Sulfonylureas (e.g., gliclazide, glimepiride): omit the day before and day of to avoid hypoglycemia.
- SGLT2 inhibitors (empagliflozin, dapagliflozin, canagliflozin): stop 3 days before to reduce risk of euglycemic ketoacidosis during fasting and stress; restart when eating normally and well hydrated.
- GLP-1 RAs (semaglutide, tirzepatide, liraglutide): usually continue, but if significant nausea/gastroparesis, consider skipping the dose closest to the procedure after clinician advice.
What to Bring
- Glucometer/CGM, spare sensors or strips, glucose tablets/gel, and a carbohydrate snack for after the exam.
- Keep a simple written plan with dose adjustments and a contact number.
Pro tips: Use clear carbohydrate fluids (e.g., apple juice, oral rehydration) the day before to prevent lows; small sips are acceptable until the facility’s cut-off time. For additional fasting strategies (timing, hydration), see Colonoscopy Prep and H. pylori eradication for overlapping “nothing-by-mouth” guidance.
GI Meds & “Darkening” Agents
Some gastrointestinal medications are perfectly safe to continue before endoscopy, while others can distort the visual field or mimic pathology on camera.
PPIs and H2 Blockers
Most acid-suppressing drugs like omeprazole, pantoprazole, famotidine, and ranitidine can be continued without interruption. They don’t interfere with visualization, biopsy results, or sedation. In fact, patients with reflux often feel more comfortable if they take their usual morning dose with a sip of water.
Iron Supplements, Bismuth, and Activated Charcoal
These substances darken the mucosa and obscure the colon or stomach lining, complicating lesion detection. They can also cause false “ink-like” residue that resembles bleeding. To avoid this, stop iron (ferrous sulfate, ferrous fumarate), bismuth subsalicylate (Pepto-Bismol), and activated charcoal 5-7 days before your procedure – unless otherwise instructed by your doctor.
These same stop windows apply to colonoscopy preparation as well. If you’re undergoing H. pylori evaluation, note that bismuth compounds must also be discontinued beforehand to prevent false-negative results.
By separating safe continuations from short-term holds, you ensure both clear visibility and accurate diagnostic sampling during the procedure.
Sedation Add-ons: Alcohol, Cannabis, OSA
Sedation safety depends not just on prescribed drugs, but also on what else is in your system. Alcohol and cannabis can both intensify the effects of anesthetics and change how your body metabolizes them.
Avoid drinking alcohol for at least 24 hours before the procedure. Even small amounts can increase sedation depth, slow recovery, and raise the risk of aspiration while under moderate anesthesia.
Cannabis: Whether smoked, vaped, or ingested, cannabis affects airway reflexes and heart rate. Regular users often require higher sedative doses, while occasional users may become over-sedated. Disclose use honestly – it helps anesthesiologists adjust safely.
Obstructive Sleep Apnea (OSA): If you use CPAP or have suspected OSA, alert the staff. Sedatives relax the airway muscles and can cause breathing pauses in unmonitored settings. You’ll likely receive a lighter dose and continuous oxygen monitoring.
Plan ahead: you’ll need a responsible adult to drive you home and stay with you for several hours after sedation. These measures make the procedure safer and recovery smoother.
After the Procedure: Restart Roadmap
Once your endoscopy is complete, your care team will provide detailed “green light” instructions for restarting medications. The exact timing depends on the type of procedure and whether biopsies or polyp removals were performed. In most cases, anticoagulants and antiplatelet agents can be restarted after there are no signs of bleeding, usually within twenty-four hours for diagnostic exams and after forty-eight to seventy-two hours for high-risk interventions.
Diabetes medications should resume only when you are able to eat normally again. Begin with small, balanced meals and monitor blood glucose closely for the first day. Over-the-counter supplements and herbal products can wait until your digestion and hydration are fully restored.
If you notice black stools, vomiting, dizziness, or new abdominal pain, contact your doctor immediately. Following these timing principles reduces the risk of both rebleeding and metabolic fluctuations, ensuring a safe and steady recovery.
Suggested Visuals/Tables
- Flowchart 1: Anticoagulant hold/resume timeline (Warfarin, DOACs, antiplatelets).
- Flowchart 2: Diabetes medication adjustment plan (insulin vs oral).
- Table: “Hold / Continue” summary by drug class and timing.
FAQs
Do I need to stop aspirin for a simple diagnostic EGD?
Usually not. Low-dose aspirin (81 mg daily) is safe for most diagnostic upper endoscopies or colonoscopies. Your gastroenterologist may only advise a pause if you’re scheduled for a therapeutic procedure such as polyp removal or mucosal resection. If in doubt, confirm with your cardiologist before changing anything.
How many days should I hold my SGLT2 inhibitor?
Stop drugs like dapagliflozin, empagliflozin, or canagliflozin three days before your endoscopy. These medications can trigger euglycemic ketoacidosis when combined with fasting or dehydration. Restart once you’re eating and drinking normally again.
Can I take blood pressure medication the morning of the procedure?
Yes. Most antihypertensive agents, including beta-blockers and ACE inhibitors, can be taken with a small sip of water. Keeping blood pressure stable helps avoid dizziness or arrhythmia during sedation. Only postpone diuretics if your doctor has specifically instructed you to.
I use cannabis-do I need to tell the team?
Absolutely. Cannabis affects airway reflexes and sedation depth. Disclosing your use allows anesthesiologists to adjust medication dosing and ensure a smooth recovery. Never assume it’s irrelevant-transparency keeps you safe.
When exactly do I restart my blood thinner?
For uncomplicated diagnostic exams, most patients restart within twenty-four hours. After higher-risk procedures, it’s usually delayed forty-eight to seventy-two hours, or until there’s no evidence of bleeding. Follow the instructions given at discharge and confirm timing with your cardiologist if you’re on dual therapy.