April 10, 2024

Best Practices for Drug Administration via Enteral Tubes

Occasionally, hospice clinicians may encounter patients with enteral feeding tubes (FTs). These tubes are used to provide enteral nutrition (EN) in individuals with a functioning GI tract who are otherwise unable to be fed orally.¹ There are numerous types of tubes out there which are generally classified by insertion site and where in the body they end up.^1-3 Also, tube type will vary by intended duration of use.^1-3

Since enteral tubes provide access to the GI tract, they can sometimes be used to administer medications in those unable to take them orally.¹ Although not all drugs are appropriate for tube administration, such as ER tablets or drugs that act locally / are absorbed at sites prior to the tube’s endpoint. Table 1 lists some drugs whose absorption / effects could be compromised depending on where the tube ends.

Table 1. Drug Effects Dependent on Tube Termination Site ^1,2

Drugs	Comments
Antacids, bismuth, and sucralfate	Act locally in the stomach; don’t administer via tubes that terminate in small intestine
Proton pump inhibitors	For tubes that terminate in jejunum or duodenum, drug should be administered as a suspension prepared with sodium bicarbonate to ensure enteric coating is dissolved
Fluoroquinolones	Mainly absorbed in the duodenum; don’t administer via tubes that terminate in jejunum
Itraconazole and ketoconazole	Mainly absorbed in the duodenum; don’t administer via tubes that terminate in jejunum
Drugs with extensive first-pass metabolism (e.g., beta-blockers, nitrates, opioids, TCAs)	Increased bioavailability and greater systemic effects if administered into jejunum

Generally, gastric tubes are preferred for drug administration since they’re larger (less likely to clog) and some medications are better tolerated in the stomach.¹ Also, liquid preparations are usually first-line since they’re less likely to occlude a tube and are readily absorbed.¹One notable exception is ciprofloxacin suspension, because its oil-based formulation adheres to feeding tubes. Of the different types of liquids available, suspensions or elixirs are preferred over syrups because they’re less likely to cause clumping if exposed to EN.¹ Notably, liquid drug formulations tend to be less concentrated (they’re usually intended for children) and the larger volumes needed for adult doses can contribute to intolerance.

Medications and some EN products may be hyperosmolar, meaning they have a higher concentration of particles dissolved in them relative to a human cell, so water gets drawn out of the cells in the intestine, which could lead to cramping and diarrhea. Specifically, sorbitol is a sweetening agent that can have an osmotic laxative effect.^1,2,4 Since patients might be taking multiple sorbitol-containing liquid formulations it’s important to be aware of their cumulative effects – the osmotic laxative effect is typically seen with sorbitol doses of 20g/day and up, but doses as low as 10g/day have been linked to bloating and flatulence.¹

When a liquid preparation isn’t an option, crushing immediate release tablets or opening capsules may be considered. Be sure to consult your organization’s do not crush list, the OPPC Clinical Symptom Guide, or your pharmacist to make sure the medication in question can be crushed / opened and is compatible with enteral tube administration. Some best practices for giving drugs via enteral tubes are described in Table 2.

Table 2. Best Practices for Medication Administration via Enteral Tube^1-4
Don't mix drugs with EN due to risk of incompatibility, decreased absorption, tube occlusion, contamination, and inability to determine amount of drug given if feedings are stopped. Instead, medications should be given separately from EN as a bolus.
Continuous gastric feedings should be paused for at least 30 minutes before and after medication administration to facilitate absorption. Feedings may need to be held up to 1 hour before and 2 hours after drug administration for optimal absorption. This doesn't apply to small bowel access sites as those feedings aren’t retained.
If GI intolerance occurs, dilute hyperosmolar medications with 10-30ml of sterile water.
Tablets should be crushed into a fine powder and mixed with 15-30ml of water. Similarly, the contents of capsules should also be mixed with water prior to administration.
Administer each medication separately and flush tube with 15-30ml of water before and after administering each medication.
Monitor for diarrhea, cramping, nausea, vomiting, therapeutic effect, and toxicity.
Avoid administering drugs likely to clog tubes (e.g., antacids, bulk-forming laxatives, cholestyramine, sevelamer, or enteric-coated tablets).

Feeding tube blockage is a significant complication that occurs in up to 35% of patients.³ This can occur due to mechanical failure, kinked tubing, feed precipitation, stagnant feeds, contamination, cyclical feeding, inappropriate medication administration, and/or inadequate flushing^1-3 Maintaining tube patency is largely dependent on following best practices, especially regular flushing.³A number of solutions (e.g., colas, juices, meat tenderizer) have been proposed as flushing agents, but nothing has been shown to be superior to water in preventing a blockage.³

If tubes should become blocked, there are a few interventions to consider: liquid irrigants (water), pancreatic enzymes, Clog Zapper and mechanical devices (Table 3).^1-3 Liquid irrigation with water and a syringe is first-line, but is often a time consuming process that requires patience.^2,3 Pancreatic enzymes (and likely Clog Zapper) appear to only be useful for clogs caused by EN and are unlikely to provide benefit for those caused by medications.³ Notably, pancreatic enzymes need to be given with sodium bicarbonate to raise pH sufficiently to “activate” the enzyme.³Finally, mechanical devices are typically meant for specific tubes and require special training.²

Table 3. Procedures for Unclogging Occluded Enteral Tubes^1-3
Liquid Irrigation
1. Draw up 15-30ml of water in a 60ml syringe
2. Instill water without forcing it in, gently and firmly push and pull plunger back and forth
3. Clamp tube for 20 minutes and allow water to “soak”
4. Repeat if necessary; it can take >30 minutes to unblock a tube
Pancreatic Enzymes
1. Thoroughly crush and dissolve one Viokace (10,440 units lipase) tablet* and one sodium bicarbonate 325mg tablet in 5ml of warm sterile water
2. Instill pancreatic enzyme / sodium bicarbonate solution using light pressure and clamp tube for 5-15minutes
3. Use warm sterile water to aspirate or flush feeding tube using a light back and forth motion with the syringe plunger
4. Repeat procedure if necessary
* A similar procedure using one opened Creon (12,000 units lipase) capsule dissolved in a mixture of one crushed sodium bicarbonate 650mg tablet and 5-10ml of sterile water has been described, but is reportedly less effective.

While most hospice patients won’t have enteral tubes as a potential route for drug administration, clinicians should be familiar with them as there are a number of considerations to ensure safe and effective medication use.

Written by: OnePoint Patient Care Clinical Team

Joseph Solien, PharmD, BCGP, BCPP – Vice President of Clinical Services

Melissa Corak, PharmD, BCGP – Senior Clinical Pharmacist

John Corrigan, PharmD, BCGP – Clinical Pharmacist

References

Toedter Williams N. Medication Administration Through Enteral Feeding Tubes. Am J Health Syst Pharm. 2008;65:2347-2357. doi: 2146/ajhp080155
A Stepwise Approach: Selecting Meds for Feeding Tube Administration. Pharmacist’s / Prescriber’s Letter. November 2020. Link.
White R, Bradnam V. Handbook of drug administration via enteral feeding tubes. 3^rd Pharmaceutical Press; 2015.
MacLaren R. Consideration when administering medications enterally in the critically ill. Curr Opin Clin Nutr Metab Care. 2023;26:302-306. doi: 1097/MCO.000000000000921

Best Practices for Drug Administration via Enteral Tubes

Table 1. Drug Effects Dependent on Tube Termination Site 1,2

Table 1. Drug Effects Dependent on Tube Termination Site ^1,2