Can furosemide (Lasix) cause pancreatitis?

Furosemide as a Cause of Acute Pancreatitis

Yes, furosemide (Lasix) can cause acute pancreatitis, although it is a rare adverse effect that should be considered in patients who develop abdominal pain while on this medication.

Evidence for Furosemide-Induced Pancreatitis

The association between furosemide and pancreatitis is documented in several case reports and is recognized as a potential adverse effect:

• Case reports have demonstrated pancreatitis developing after furosemide administration with positive rechallenge evidence 1
• A documented case showed a patient with renal insufficiency and malignant hypertension developing acute pancreatitis with abdominal symptoms and hyperamylasemia after treatment with loop diuretics (furosemide and bumetanide) 2
• Another case report described a patient with a sulfonamide allergy who developed pancreatitis after exposure to various loop diuretics including furosemide, bumetanide, and torsemide 3

Mechanism and Risk Factors

The mechanism of furosemide-induced pancreatitis appears to be immunologically mediated rather than dose-dependent:

• The time delay between administration and symptom onset suggests an immunologic pathway 3
• Patients with sulfonamide allergies may be at higher risk due to potential cross-reactivity between sulfonamide antibiotics and non-antibiotic sulfonamides like furosemide 3
• The risk may be higher in patients with renal insufficiency who may have reduced clearance of the medication 2

Clinical Implications

When prescribing furosemide, clinicians should:

1. Consider pancreatitis in the differential diagnosis of patients on furosemide who present with epigastric pain, especially if radiating to the back
2. Monitor for elevated pancreatic enzymes in patients with suspicious symptoms
3. Be particularly cautious in patients with a history of sulfonamide allergies
4. Consider alternative diuretics in patients with a history of pancreatitis

Management of Suspected Cases

If furosemide-induced pancreatitis is suspected:

1. Discontinue furosemide immediately
2. Provide supportive care for acute pancreatitis
3. Consider alternative diuretics if needed:
   • For patients with liver cirrhosis and ascites, spironolactone is the preferred first-line diuretic 4
   • For patients with heart failure, consider ethacrynic acid (which lacks a sulfonamide group) or cautious desensitization to furosemide if absolutely necessary 3
   • For patients with renal insufficiency, careful monitoring is required with any diuretic

Documentation in Guidelines

While major guidelines on diuretic therapy mention various adverse effects of furosemide, pancreatitis is not prominently featured in most clinical practice guidelines. However, the DPP-4 inhibitor class of medications is specifically noted to have pancreatitis as a potential adverse effect in diabetes guidelines 4, highlighting that medication-induced pancreatitis is a recognized clinical entity that warrants attention.

Conclusion

Although rare, furosemide-induced pancreatitis is a documented adverse effect that clinicians should be aware of, particularly in patients with risk factors such as sulfonamide allergies or renal insufficiency. Prompt recognition and discontinuation of the medication is essential when this adverse effect is suspected.