HCA 105 Module 3 Routes of Administration Example

Same Drug, Different Road: How the Route of Administration Changes Onset, Dose and Safety

Student Name

Health Care Administration Program, Aspen University

HCA 105: Pharmacology

Instructor Name

Month Day, Year

Same Drug, Different Road: How the Route of Administration Changes Onset, Dose and Safety

The same drug can act quickly or slowly, strongly or weakly, depending on how it enters the body. Allied health workers who prepare, give or record medications need to understand routes of administration, both to follow orders correctly and to recognize when a route has been confused. This paper describes the main routes, explains why doses differ between them, outlines injection basics and sets out the safety checks each route requires.

The Main Routes

Routes fall into broad groups. Enteral routes use the digestive tract, including oral, sublingual and rectal. Parenteral routes bypass the digestive tract, usually by injection, including intravenous, intramuscular, subcutaneous and intradermal. Topical routes apply drugs to skin or mucous membranes for local effect, transdermal patches deliver drugs through the skin into the blood over time, and inhaled drugs reach the lungs directly (Lilley et al., 2023).

The First-Pass Effect

Drugs swallowed by mouth are absorbed from the intestine and carried to the liver before they reach the rest of the body. The liver breaks down part of some drugs on this first pass, so less active drug reaches the circulation. Nitroglycerin is a clear example: so much is broken down on the first pass that it is given under the tongue, where it is absorbed directly into the blood and acts within minutes (Lilley et al., 2023). The first-pass effect is one reason oral and intravenous doses of the same drug often differ.

Absorption, Distribution and Elimination in Brief

Route affects only the first part of a drug's journey. After absorption, drugs are distributed through the blood to tissues, broken down, mostly in the liver, and eliminated, mostly by the kidneys. Age, liver disease and kidney disease change these steps, which is why older adults and people with kidney problems often need lower doses. Allied health workers do not adjust doses, but understanding why a provider chose a lower dose for an older patient helps them explain it and avoid the mistaken assumption that a smaller dose is an error.

Why Doses Differ by Route

Because routes differ in how much drug reaches the blood and how fast, a dose written for one route may be wrong for another. An intravenous dose goes entirely into the circulation, while an oral dose may be partly lost to digestion and the liver. For this reason, a route must never be changed without a new order, and a route written unclearly must be clarified before a drug is given. Confusing routes, for example giving an oral liquid by injection, has caused serious harm.

Injection Basics

Where state law and training allow allied health workers to give injections, technique matters. Intramuscular injections go into muscle, commonly the deltoid in adults for small volumes, at a 90-degree angle. Subcutaneous injections go into the fatty tissue under the skin, often of the abdomen or the back of the upper arm, at 45 to 90 degrees depending on needle length and tissue. Intradermal injections, such as the tuberculin skin test, go just under the surface at a shallow angle and raise a small bleb. Needle length and gauge are chosen for the route and the patient.

Safety Checks for Each Route

Each route adds its own checks. For oral drugs, staff confirm the patient can swallow and whether the drug should be taken with food. For injections, they check the site, use a new sterile needle, never recap by hand and dispose of sharps immediately. For inhalers, they check technique, since poor technique delivers little drug. For patches, they remove the old patch, date the new one and rotate sites. For every route, the core checks remain: the right patient, drug, dose, route, time and documentation. Continuing to learn is itself a professional expectation for medical assistants (American Association of Medical Assistants, n.d.), and route-specific checks are part of that knowledge.

A Near Miss at the Clinic

At the composite clinic, an order for a vitamin B12 injection read 1,000 mcg intramuscularly. A new medical assistant prepared it but paused because the vial label mentioned intravenous use as well and the order was handwritten. The assistant asked the nurse, who confirmed the intramuscular route with the provider and documented it. Nothing went wrong, but the pause was exactly right: an unclear route is a reason to stop and ask.

Route Abbreviations

Written routes are sometimes abbreviated, and some abbreviations cause confusion. IM for intramuscular and IV for intravenous are widely understood, but abbreviations for subcutaneous have been misread, and many organizations require that route to be written out. When an abbreviated route is unclear or unfamiliar, the safe response is to ask before preparing the drug. Writing routes in full in patient instructions avoids confusion for patients as well.

Teaching Patients About Routes

Patients also need to understand routes. A patient given a sublingual tablet must know not to swallow it, a patient with a patch must know not to cut it, and an inhaler user must know how to time the breath. Allied health workers often reinforce this teaching, using simple demonstrations and asking the patient to show the technique back. Teach-back, in which patients explain or demonstrate what they have learned, is widely used in patient education and has been associated with better understanding and self-management (Talevski et al., 2020).

Conclusion

Routes of administration determine how fast a drug acts, how much reaches the blood and what can go wrong. The first-pass effect explains why oral and intravenous doses differ and why some drugs are given under the tongue. For allied health workers, the key lessons are never to change a route without an order, to stop and ask when a route is unclear, and to pair every route with its own safety checks.

References

American Association of Medical Assistants. (n.d.). AAMA medical assistant code of ethics. https://www.aama-ntl.org

Lilley, L. L., Collins, S. R., & Snyder, J. S. (2023). Pharmacology and the nursing process (10th ed.). Elsevier.

Talevski, J., Wong Shee, A., Rasmussen, B., Kemp, G., & Beauchamp, A. (2020). Teach-back: A systematic review of implementation and impacts. PLOS ONE, 15(4), Article e0231350. https://doi.org/10.1371/journal.pone.0231350