Examkin

Question

Difficulty: Very hardPharmacological Therapies

A client with a seizure disorder is receiving continuous enteral nutrition via a percutaneous endoscopic gastrostomy (PEG) tube. The practical nurse must administer a scheduled dose of phenytoin oral suspension through the tube. Arrange the following actions in the correct sequence to ensure safe administration and maximize drug absorption.

  1. 1Stop the continuous enteral feeding 1 to 2 hours prior to the scheduled medication time.
  2. 2Verify gastrostomy tube placement and measure the gastric residual volume.
  3. 3Flush the gastrostomy tube with 30 mL of water.
  4. 4Administer the prescribed dose of liquid phenytoin suspension.
  5. 5Flush the gastrostomy tube with an additional 30 mL of water.
  6. 6Keep the enteral feeding paused for 1 to 2 hours before restarting the continuous infusion.

Answer

The correct sequence requires stopping the feeding 1-2 hours before, verifying tube placement/residual, flushing with water, administering the phenytoin, flushing again with water, and leaving the feeding off for another 1-2 hours.
Phenytoin has a well-documented and severe interaction with enteral nutritional formulas. The formula significantly decreases the gastrointestinal absorption of the drug, which can lead to subtherapeutic serum levels and seizures. Therefore, the feeding must be stopped 1 to 2 hours before administration. Standard tube medication safety follows: verify placement and residual, flush with water, administer the medication, and flush again. Finally, the feeding must remain off for an additional 1 to 2 hours to allow the drug to absorb fully without interference.

Step-by-Step Solution

1
Stop the continuous enteral feeding 1 to 2 hours prior to the scheduled medication time.
The stomach empties of formula before the medication arrives.
Enteral formula contains proteins and calcium that heavily bind to phenytoin, leading to subtherapeutic drug levels and potential breakthrough seizures.
2
Verify gastrostomy tube placement and measure the gastric residual volume.
Safe route for administration is confirmed.
Checking placement and residual prevents pulmonary aspiration and ensures the gastrointestinal tract is tolerating fluids.
3
Flush the gastrostomy tube with 30 mL of water.
The internal lumen of the tube is cleared of formula.
This prevents direct physical incompatibility and crystallization between the enteral formula and the phenytoin suspension inside the tube.
4
Administer the prescribed dose of liquid phenytoin suspension.
The therapeutic agent is delivered.
Phenytoin must be given as an isolated suspension to ensure proper absorption.
5
Flush the gastrostomy tube with an additional 30 mL of water.
The medication is completely cleared from the tubing.
Ensures the client receives the full prescribed dose and prevents tube occlusion from the medication.
6
Keep the enteral feeding paused for 1 to 2 hours before restarting the continuous infusion.
The drug absorbs fully across the gastrointestinal mucosa without interference.
Immediate resumption of feeding would cause the formula to bind to the phenytoin in the stomach, rendering the medication ineffective.

Key Concept

Enteral administration of phenytoin requires strictly holding continuous nutritional feedings 1 to 2 hours before and after administration to prevent decreased drug bioavailability due to protein binding.
Rate this question

Topics

Pharmacological Therapies

More questions from this topic