Is it safe to administer Cymbalta (duloxetine) through a jejunostomy (j-) tube?

Administration of Duloxetine Through a J-Tube

Duloxetine (Cymbalta) should not be administered through a jejunostomy tube as its enteric-coated pellets must remain intact to prevent degradation in the stomach and maintain drug efficacy.

Understanding Duloxetine's Formulation

Duloxetine is formulated as enteric-coated pellets contained within capsules. This specific formulation serves important purposes:

• The enteric coating protects the medication from degradation by stomach acid
• It ensures the drug is released in the small intestine for proper absorption
• Breaking or crushing the pellets would compromise the enteric coating

Evidence on Administration Options

Research specifically examining duloxetine administration through enteral tubes is limited, but available evidence provides clear guidance:

• In vitro studies show that duloxetine's enteric coating is compromised when exposed to certain food substances, particularly those with higher pH like chocolate pudding 1
• The integrity of the enteric coating is critical for maintaining drug potency and effectiveness 1
• When the enteric coating is damaged, dissolution testing shows premature release of the medication (90% release during the gastric challenge portion) 1

Risks of Improper Administration

Administering duloxetine through a j-tube presents several significant risks:

• Premature breakdown of the medication due to disruption of the enteric coating
• Reduced drug efficacy due to degradation in acidic environments
• Potential for tube clogging due to the pellet formulation
• Inconsistent drug delivery and unpredictable blood levels

General Principles for Medication Administration via Enteral Tubes

While not specific to duloxetine, clinical guidelines provide important context:

• The ESPEN guideline on home enteral nutrition states that enteral tubes can be used for drug administration only "if the efficacy of drug administration can be confirmed" 2
• Medications administered through enteral tubes should not compromise tube patency or drug efficacy 2
• A pharmacist should be consulted when considering medication administration through enteral tubes 2, 3
• Never crush enteric-coated or extended-release formulations for tube administration 3

Alternative Approaches

For patients requiring duloxetine who have a j-tube:

1. Consider alternative SNRI medications available in liquid formulations
2. Consult with a psychiatrist about equivalent medications that can be safely administered through j-tubes
3. If duloxetine is absolutely necessary, discuss with the prescriber about potential alternative routes of administration

Conclusion

Based on the available evidence, administering duloxetine through a j-tube is not recommended due to the enteric-coated formulation that would be compromised during preparation and administration. The risks of reduced efficacy and potential tube occlusion outweigh any potential benefits of this administration route.