The short answer
- Sucralfate (Carafate): 1 g, usually four times a day, 1 hour before meals and at bedtime, on an empty stomach.
- Famotidine (Pepcid): take it at least 2 hours away from sucralfate; a bedtime dose can be taken 2 hours before the bedtime sucralfate, or famotidine can be taken with breakfast.
- Antacids: not within 30 minutes before or after sucralfate.
Why they are prescribed together
Sucralfate is an aluminium-sucrose compound. In the acid of the stomach it forms a sticky paste that binds to the base of ulcers and inflamed areas, shielding them from acid, pepsin and bile while they heal. Very little is absorbed. Famotidine is an H2 blocker that reduces how much acid the stomach makes. Together they protect the lining and lower the acid attacking it. This combination is used for duodenal and stomach ulcers, stress-related gastritis, and sometimes oesophagitis or bile reflux. Many doctors now prefer a proton pump inhibitor for ulcers; the stomach medicines guide compares the options.
A sample daily schedule
Example for sucralfate 1 g four times a day and famotidine 20 mg twice a day. Adjust the clock times to your meals.
| Time |
What to take |
| 07:00 (on waking) |
Sucralfate 1 g with water, empty stomach |
| 08:00 |
Breakfast |
| 09:00 |
Famotidine 20 mg (2 hours after sucralfate) and other morning medicines |
| 11:30 |
Sucralfate 1 g |
| 12:30 |
Lunch |
| 17:00 |
Sucralfate 1 g |
| 18:00 |
Dinner |
| 20:00 |
Famotidine 20 mg |
| 22:00 (bedtime) |
Sucralfate 1 g |
If your prescription is sucralfate twice a day (for example 1 g before breakfast and at bedtime), famotidine fits easily at lunchtime or early evening. The principle is the same: nothing else within 2 hours of a sucralfate dose if you can help it.
Spacing other medicines from sucralfate
Sucralfate can bind or reduce the absorption of several medicines. Take these at least 2 hours before sucralfate:
- Levothyroxine (thyroid)
- Antibiotics such as ciprofloxacin, levofloxacin, norfloxacin and tetracyclines
- Digoxin, warfarin, phenytoin, theophylline
- Ketoconazole
- Famotidine and other H2 blockers, and most once-daily medicines (to be safe)
Spacing rules for antacids, minerals and other absorption-sensitive medicines are summarised in our guide to combining medicines.
Practical tips
- Large tablets: sucralfate 1 g tablets can be dissolved in about 10–15 mL of water and swallowed as a slurry. A liquid (1 g/10 mL suspension) is also available.
- Constipation is the most common side effect; drink fluids and add fibre.
- Kidney disease: the aluminium can accumulate; long-term use needs medical supervision.
- Diabetes: some sucralfate suspensions contain sugar, and high blood sugar has been reported; check glucose if you notice changes.
- Feeding tubes: sucralfate can form clumps; follow your hospital’s advice.
Frequently asked questions
Can I take famotidine and sucralfate at the same time?
It’s better not to. Sucralfate may reduce famotidine absorption slightly, and it works best on an empty stomach. Separate them by about 2 hours.
How long should I take sucralfate?
Usually 4–8 weeks for an ulcer, as prescribed. Don’t stop early because symptoms improve; the ulcer may not have healed.
Can I take Gaviscon with sucralfate?
Keep antacids and alginates at least 30 minutes away from sucralfate, and preferably longer, so they don’t interfere with how it coats the stomach.
Sources and further reading
CanforaMedicine Guide
