Enteral Medication Routes in EMS

• The enteral route is a method of administering medications through the gastrointestinal (GI) tract
• It is a less invasive and slower method than parenteral administration
• It is an essential component of prehospital pharmacology

Key Enteral Routes in EMS

• Oral (PO) administration involves swallowing a medication for absorption in the GI tract.
• Buccal administration involves placing a medication between the cheek and gum, where it is absorbed through mucous membranes.
• Sublingual (SL) administration involves placing a medication under the tongue for rapid absorption.
• Rectal (PR) administration is used when oral administration is not feasible
• Orogastric/Nasogastric (OG/NG) Tube administration is for patients with enteral tubes for direct gastric delivery

Advantages of Enteral Administration

• Non-invasive and convenient
• Lower risk of infection
• Suitable for self-administration

Disadvantages of Enteral Administration

• Slower onset of action
• Absorption can be affected by food, gastric pH, or motility
• First-pass metabolism in the liver reduces bioavailability
• Not suitable for unconscious or vomiting patients

Pharmacokinetics of Enteral Medications

• GI pH and enzymes affect drug solubility
• Some drugs require an empty stomach for optimal absorption
• The small intestine has the largest surface area for absorption

First-Pass Metabolism

• Medications absorbed through the GI tract enter the hepatic portal system, where the liver metabolizes them before reaching systemic circulation
• This reduces drug bioavailability compared to intravenous administration

Enteric-Coated and Extended-Release Medications

• Enteric-coated (EC) drugs protect against stomach acid and dissolve in the intestines
• Extended-release (ER, XR, SR) drugs provide prolonged therapeutic effects
• Do not crush or split enteric-coated or extended-release medications unless approved by a pharmacist or medical direction

Special Considerations in EMS

• Nitroglycerin (NTG) SL allows for rapid absorption and bypasses first-pass metabolism
• Glucose Gel Buccal is for hypoglycemia when a patient is awake and able to swallow
• Rectal (PR) administration is used for seizures (diazepam PR) or when IV/PO is not possible, and is faster than oral but slower than IV absorption
• Orogastric/Nasogastric Tube administration is for patients with enteral feeding tubes
• Ensure proper tube placement verification before medication administration, and flush with water before and after administration to maintain patency

The "Six Rights" of Medication Administration

• Right Patient: Verify patient identity
• Right Medication: Check the label three times
• Right Dose: Perform accurate dosage calculations
• Right Route: Confirm appropriate enteral route
• Right Time: Ensure proper timing of medication
• Right Documentation: Record administration immediately after delivery

Avoiding Medication Errors and Documentation

• Use plain language when instructing patients and confirm allergies and contraindications
• Monitor for adverse effects (nausea, vomiting, diarrhea), and double-check pediatric and geriatric doses
• Document medication given (name, dose, route, time) and patient response (effectiveness, side effects), as well as any adverse reactions or refusal of medication

Sample Practice Questions

• Sublingual administration allows direct absorption into the systemic circulation, bypassing first-pass metabolism
• Enteric-coated tablets protect the medication from stomach acid
• Sublingual nitroglycerin is absorbed directly into the bloodstream through the mucous membranes under the tongue, bypassing the gastrointestinal tract and first-pass metabolism in the liver. This allows for rapid systemic absorption and onset of action
• Oral nitroglycerin must pass through the digestive system, delaying its effects

Three Advantages of Enteral Medication Administration

• Ease of administration
• Cost-effective
• Safer than parenteral routes

Three Disadvantages of Enteral Medication Administration

• First-pass metabolism
• Delayed onset
• GI-related issues (nausea, vomiting, or malabsorption)

Pediatric Dosage Calculation Using Clark’s Rule

• Clark’s Rule is a weight-based formula used to determine pediatric medication dosages: Child's Dose = (Weight in lbs / 150) × Adult Dose
• Measure pediatric weight in kilograms whenever possible and be aware of drug pharmacokinetics (immature liver and renal function)
• Some drugs require dilution or specialized dosing to ensure safe administration
• The calculated dose should not exceed the recommended pediatric limit

Why Avoid Crushing Enteric-Coated or Extended-Release Medications?

• Crushing enteric-coated medications, which are designed to resist stomach acid and dissolve in the intestines, can lead to stomach irritation or drug inactivation
• Crushing extended-release (ER, XR, SR) medications, which are formulated to release the drug gradually over time, can result in a dose dumping effect, causing toxicity due to rapid absorption