Sucralfate: a practical guide to uses, dosing and safety

Sucralfate is a local medicine that protects damaged stomach and duodenal tissue. It isn’t absorbed much into the body. Instead, it forms a sticky protective coat over ulcers and irritated areas so acid and enzymes can't make the injury worse. That makes it useful when you need local protection rather than systemic acid suppression.

How sucralfate works and when to take it

Doctors most often prescribe sucralfate for active duodenal ulcers and for healing erosive esophagitis when other drugs aren’t suitable. Hospitals also use it to prevent stress ulcers. You usually take it as a 1 g tablet or as a liquid suspension. Common timing: take sucralfate on an empty stomach, typically one hour before meals and at bedtime. That gives the drug time to stick to the injured area before food arrives.

For many adults the typical dose is 1 g four times a day. Your doctor may adjust that based on your condition. Don’t skip doses and don’t stop early just because you feel better—ulcers need time to heal.

Safety, side effects and drug interactions

Sucralfate is generally well tolerated. The most common side effect is constipation. Some people report nausea, dry mouth, or upset stomach. Because it contains aluminum, it can build up in people with severe kidney disease. If you have kidney problems, tell your doctor—sucralfate might not be the best choice.

Sucralfate can interfere with the absorption of other medications. Antibiotics like ciprofloxacin and tetracyclines, thyroid pills, phenytoin, digoxin and warfarin are examples that may bind to sucralfate and become less effective. A good rule: take other medicines at least two hours before or after sucralfate. Also avoid antacids within 30 minutes of a dose, because antacids can prevent the protective coat from forming properly.

Pregnancy and breastfeeding: there’s limited data. Because sucralfate acts locally and is barely absorbed, many clinicians consider it relatively safe, but check with your provider before starting it.

Practical tips: swallow tablets whole with a glass of water or mix the liquid form well before each dose. If you use the suspension, shake it and measure with a proper device. Keep taking the medicine for the full course your doctor prescribes. If symptoms return after stopping, contact your doctor rather than restarting on your own.

Wondering about alternatives? Proton pump inhibitors and H2 blockers reduce stomach acid and help many people heal faster, but they work differently and carry different risks. Your doctor will weigh your symptoms, other drugs you take, and your kidney function when choosing the best option.

If you have severe belly pain, vomiting blood, black stools, or fainting, seek emergency care. For routine questions about dosing, side effects, or interactions, call your pharmacist or prescriber—small changes matter when medicines interact.