Can morphine be administered via a Percutaneous Endoscopic Gastrostomy (PEG) tube?

Morphine Administration via PEG Tube

Yes, morphine can be administered via a PEG tube, but proper administration techniques must be followed to ensure efficacy and prevent tube occlusion. 1

Administration Guidelines

Preparation and Administration

1. Formulation selection:

   • Liquid morphine formulations are preferred (elixirs or solutions) 2
   • Immediate-release morphine tablets may be crushed and dissolved in water if liquid forms are unavailable 1
   • Extended-release morphine formulations should NOT be crushed or administered via PEG tube as this destroys the extended-release properties and may cause dose dumping 3

2. Administration technique:

   • Flush the PEG tube with 30 mL of water before administration 1
   • Administer each medication separately (do not mix medications) 1
   • Flush with 30 mL of water between medications 1
   • Flush with 30 mL of water after the final medication 1

3. Equipment:

   • Use appropriate ENFit syringes and connectors to prevent misconnection errors 1
   • Do not shake low-dose ENFit tip syringes to remove drug moat as this can affect dose accuracy 1

Clinical Considerations

Dosing

• When converting from oral to PEG administration of morphine, use a 1:1 dose ratio (same dose) 1
• This differs from parenteral routes, where oral-to-subcutaneous/intravenous conversion requires dividing the oral dose by 2-3 1

Potential Issues

1. Drug-formula interactions:

   • Consider temporarily stopping enteral feeding for 30 minutes before and after morphine administration if absorption issues are suspected 1
   • Resume feeding after administration to prevent drug-nutrient interactions 1

2. Tube occlusion prevention:

   • Never add morphine directly to enteral formula 2
   • Ensure adequate flushing before and after administration 1
   • If crushing tablets, ensure they are completely dissolved in water 2

Alternative Options

If PEG administration proves problematic, consider these alternatives:

1. Alternative routes:

   • Subcutaneous infusion (preferred parenteral route) 1
   • Intravenous administration (if IV access already exists) 1
   • Transdermal fentanyl (for stable pain requirements) 1
   • Rectal suppositories (bioavailability similar to oral route) 1, 4

2. Alternative opioids:

   • Oxymorphone immediate release has been successfully used via G-tubes at 8-hour intervals 5

Common Pitfalls to Avoid

1. Never crush extended-release morphine formulations - this destroys the time-release mechanism and can cause dangerous dose dumping 3

2. Avoid mixing medications together before administration through the PEG tube, as this increases risk of incompatibilities and tube occlusion 1

3. Don't administer morphine without proper flushing before and after, as inadequate flushing is a primary cause of tube occlusion 1

4. Don't add morphine directly to enteral formula as this can cause precipitation and reduced drug efficacy 2

5. Avoid buccal or sublingual administration of morphine as absorption by these routes is unpredictable 1

By following these guidelines, morphine can be safely and effectively administered via PEG tube to provide adequate pain control while maintaining tube patency.