Carafate - Drug Monograph

Introduction

Carafate (sucralfate) is a unique gastrointestinal medication that has been used clinically for decades. It is a complex salt of sucrose sulfate and aluminum hydroxide that acts locally rather than systemically. Unlike many other ulcer medications, Carafate does not neutralize gastric acid or reduce acid secretion but instead forms a protective barrier over ulcerated tissue.

Mechanism of Action

Carafate exerts its therapeutic effects through several local mechanisms:

• Forms a viscous, adhesive substance that binds selectively to ulcer sites
• Creates a protective barrier that shields damaged mucosa from gastric acid, pepsin, and bile
• Inhibits pepsin activity by approximately 30%
• Adsorbs bile salts, reducing their damaging effects on gastric mucosa
• May stimulate mucosal prostaglandin production and enhance bicarbonate secretion
• Promotes angiogenesis and epithelial cell regeneration at ulcer sites

Indications

FDA-approved indications:

• Short-term treatment (up to 8 weeks) of active duodenal ulcers
• Maintenance therapy for duodenal ulcer patients at reduced dosage after healing of acute ulcers

Off-label uses (evidence-supported):

• Treatment of gastric ulcers
• Prevention of stress ulcers in critically ill patients
• Treatment of gastroesophageal reflux disease (GERD)
• Management of radiation-induced proctitis
• Treatment of oral and esophageal ulcers
• Prevention of NSAID-induced gastric damage

Dosage and Administration

• Adults: 1 g orally four times daily on an empty stomach (1 hour before meals and at bedtime)
• Duration: 4-8 weeks

• Adults: 1 g orally twice daily on an empty stomach

• Renal impairment: Use with caution; aluminum may accumulate
• Hepatic impairment: No dosage adjustment typically needed
• Elderly: Consider reduced frequency in patients with renal impairment
• Pediatrics: Safety and effectiveness not established

• Should be administered on an empty stomach
• Tablets should be swallowed whole with water
• Avoid antacids within 30 minutes before or after administration
• Space other medications by at least 2 hours

Pharmacokinetics

Contraindications

• Hypersensitivity to sucralfate or any component of the formulation
• Patients with known aluminum toxicity
• Intestinal obstruction (theoretical risk of bezoar formation)

Warnings and Precautions

• Risk in patients with renal impairment (including elderly)
• May lead to osteomalacia, encephalopathy, or microcytic anemia

• Theoretical risk in patients with delayed gastric emptying
• Use caution in patients with gastroparesis or diabetes

• Most common adverse effect (2-3% of patients)
• May be severe in some cases

• May impair absorption of many concurrently administered medications

• Pregnancy Category B: Use only if clearly needed
• Nursing mothers: Aluminum is excreted in human milk
• Pediatric use: Not recommended

Drug Interactions

• Antacids: Reduced efficacy of both medications (space administration)
• Fluoroquinolones: Reduced absorption (↓ AUC by 30-50%)
• Tetracyclines: Reduced absorption (↓ AUC by 30-40%)
• Phenytoin: Reduced absorption (↓ levels by 10-20%)
• Digoxin: Reduced absorption (↓ levels by 10-15%)
• Thyroid hormones: Reduced absorption (↓ T4 levels)
• Warfarin: Possible reduced absorption (monitor INR closely)
• Ketoconazole: Significantly reduced absorption

• Administer interacting drugs at least 2 hours before Carafate
• Monitor drug levels or clinical response when appropriate
• Consider alternative ulcer therapy if multiple interactions anticipated

Adverse Effects

• Constipation (2.2%)
• Diarrhea (1.3%)
• Nausea (1.1%)
• Gastric discomfort (1.0%)
• Dry mouth (0.5%)

• Headache
• Dizziness
• Sleep disturbances
• Back pain
• Rash/pruritus

• Aluminum toxicity (in renal impairment)
• Bezoar formation
• Hypophosphatemia
• Allergic reactions including anaphylaxis

Monitoring Parameters

• Symptom improvement (pain relief)
• Endoscopic ulcer healing (if indicated)
• Hemoglobin/hematocrit (if bleeding ulcer)

• Bowel function (constipation)
• Serum aluminum levels (in renal impairment)
• Serum phosphate levels (with long-term use)
• Renal function (periodically)
• Signs of aluminum toxicity (neurological changes, bone pain)

• Concentrations of co-administered drugs with known interactions
• INR in patients on warfarin

Patient Education

• Take on an empty stomach (1 hour before meals and at bedtime)
• Swallow tablets whole with a full glass of water
• Do not crush or chew tablets
• Space other medications by at least 2 hours

• Avoid smoking and alcohol, which can delay ulcer healing
• Follow prescribed dietary recommendations
• Report persistent constipation to healthcare provider

• Pain relief may occur within 1-3 weeks
• Complete ulcer healing typically takes 4-8 weeks
• Continue full course even if symptoms improve

• Severe constipation unrelieved by laxatives
• Black, tarry stools or vomiting blood
• Signs of allergic reaction (rash, swelling, difficulty breathing)
• Neurological symptoms (confusion, speech difficulties)

• Store at room temperature (15-30°C/59-86°F)
• Keep container tightly closed
• Protect from moisture

References

1. US Food and Drug Administration. (2021). Carafate prescribing information. 2. McCarthy DM. (1991). Sucralfate. New England Journal of Medicine, 325(14), 1017-1025. 3. Nagashima R. (1981). Mechanisms of action of sucralfate. Journal of Clinical Gastroenterology, 3(Suppl 2), 117-127. 4. Lamers CB. (1995). Sucralfate maintenance therapy in duodenal ulcer disease. Alimentary Pharmacology & Therapeutics, 9(2), 187-191. 5. American Society of Health-System Pharmacists. (2023). AHFS Drug Information. 6. Thomson MICROMEDEX® Healthcare Series. (2023). Sucralfate monograph. 7. Clinical Pharmacology [database online]. (2023). Sucralfate. 8. UpToDate. (2023). Sucralfate: Drug information. 9. Nagashima R. (1980). Development and characteristics of sucralfate. Journal of Clinical Gastroenterology, 2(Suppl 1), 1-6. 10. Weinberg DS. (1985). Sucralfate. Annals of Internal Medicine, 103(1), 135-136.