Pharmacology and Medication Administration

TL;DR

Pharmacology is all about how medications affect the body and what the body does to them. Medication administration focuses on giving meds safely and effectively, following specific rights and preventing errors. Understanding both helps you provide safe and effective patient care.

1. The Mental Model

Think of medications as keys and your body as a complex set of locks. Pharmacology explains which keys fit which locks (effects) and how your body handles those keys (absorption, distribution, metabolism, excretion). Medication administration is about being the careful, precise person making sure the right key gets to the right lock at the right time.

2. The Core Material

Pharmacology and medication administration are two sides of the same coin in nursing. You can't safely administer a drug without understanding its pharmacology.

Understanding Pharmacology

Pharmacology covers two main areas:

• Pharmacokinetics (What the Body Does to the Drug - ADME):

  • Absorption: How the drug gets into the bloodstream from its administration site (e.g., mouth, muscle, skin). Different routes have different absorption rates.
  • Distribution: How the drug travels from the bloodstream to different body tissues and organs. Factors like blood flow and protein binding affect this.
  • Metabolism: How the body breaks down the drug, usually in the liver, into metabolites that are easier to excrete. This can make the drug active or inactive.
  • Excretion: How the body gets rid of the drug and its metabolites, primarily through the kidneys in urine, but also feces, sweat, and breath.

• Pharmacodynamics (What the Drug Does to the Body):

  • Mechanism of Action: How the drug produces its therapeutic effect at the cellular or molecular level (e.g., binding to receptors, inhibiting enzymes).
  • Therapeutic Effects: The desired, beneficial effects of the drug.
  • Side Effects/Adverse Reactions: Undesirable effects, ranging from mild (e.g., nausea) to severe (e.g., anaphylaxis).
  • Contraindications: Specific situations where a drug should not be used due to potential harm.
  • Drug Interactions: How one drug can affect the action of another, or how food can affect a drug.

Principles of Medication Administration

Photo by RDNE Stock project on Pexels

Safe medication administration hinges on the "Rights" and a systematic approach to prevent errors.

graph TD
    A["Medication Order Rec'd"] --> B["Right Patient?"]
    B --> C["Right Drug?"]
    C --> D["Right Dose?"]
    D --> E["Right Route?"]
    E --> F["Right Time?"]
    F --> G["Right Documentation?"]
    G --> H["Right Reason?"]
    H --> I["Right Assessment?"]
    I --> J["Right Response?"]
    J --> K["Administer & Monitor"]

The "Rights" of Medication Administration (Often 7, sometimes 10)

These are your bedrock for safe practice. Always check these multiple times before administering:

1. Right Patient: Always verify patient identity using at least two identifiers (e.g., name, date of birth, medical record number).
2. Right Drug: Ensure it's the prescribed medication. Double-check the label against the order.
3. Right Dose: Calculate carefully and verify it matches the order. Pay attention to units.
4. Right Route: Administer via the prescribed route (e.g., oral, IV, IM, SQ). Never substitute.
5. Right Time: Give the medication at the scheduled time, considering hospital policies for timing windows.
6. Right Documentation: Record administration immediately after giving the medication, including dose, route, time, and your initials.
7. Right Reason: Understand why the patient is receiving this medication.
8. Right Assessment: Perform necessary assessments before administration (e.g., vital signs, lab values, pain level).
9. Right Response: Evaluate the patient's response to the medication (therapeutic effect, side effects).
10. Right to Refuse: Patients have the right to refuse medication. Document this and notify the prescriber.

Error Prevention Strategies

• Three Checks: Compare the medication label with the MAR (Medication Administration Record) or order at three points:
  1. When you pull the medication from the dispensing system.
  2. When you prepare the medication (e.g., drawing it up, scanning).
  3. At the patient's bedside before administration.
• Avoid Distractions: Prepare medications in a quiet environment.
• Clarity: Question illegible or unclear orders.
• Patient Education: Inform the patient about the medication.

3. Worked Example

Let's say you have an order for "Acetaminophen 650 mg PO Q6H PRN pain."

1. Check the MAR/Order:
   • Right Patient: You confirm it's for John Smith, DOB 05/10/1950.
   • Right Drug: Acetaminophen.
   • Right Dose: 650 mg.
   • Right Route: PO (by mouth).
   • Right Time: Q6H (every 6 hours) PRN (as needed) pain.
   • Right Reason: John is complaining of 6/10 back pain.
2. Assessment (Right Assessment):
   • You ask John about his pain level (6/10), when he last received pain meds (8 hours ago), and if he has any allergies (none to acetaminophen). You check his liver function labs, which are within normal limits (important for acetaminophen due to metabolism).
3. Prepare the Medication (Three Checks):
   • You go to the med cart and pull a bottle of "Acetaminophen 325 mg tablets." (1st check)
   • You calculate the dose: 650 mg / 325 mg/tablet = 2 tablets. You open the foil packets for 2 tablets. (2nd check)
4. Administer at Bedside:
   • You enter John's room, confirm his name and DOB.
   • You show him the medication and explain, "This is acetaminophen for your back pain."
   • You hand him the 2 tablets with water. (3rd check)
   • Right to Refuse: John takes the medication without issues.
5. Document (Right Documentation):
   • Immediately after he swallows, you document: "Acetaminophen 650 mg PO administered at 1400 for 6/10 back pain. Patient tolerated well."
6. Monitor (Right Response):
   • An hour later, you check on John. His pain is now 2/10. Therapeutic effect achieved.

4. Key Takeaways

• Pharmacology covers what the body does to drugs (pharmacokinetics - ADME) and what drugs do to the body (pharmacodynamics).
• Always adhere to the "Rights" of medication administration (patient, drug, dose, route, time, documentation, reason, assessment, response, refusal).
• Use the "Three Checks" method to compare the medication label with the order multiple times.
• Understanding a drug's metabolism and excretion helps predict potential toxicities or interactions.
• Assess your patient before giving medication and evaluate their response after administration.

Common Mistakes to Avoid:

• Not checking patient identifiers: Always use two, every time.
• Calculating doses incorrectly: Double-check calculations, especially with unfamiliar drugs or dosages.
• Administering without knowing the "why": Always understand the medication's purpose and potential side effects.
• Documenting before administration: This is a major error; only document after the medication is given.
• Ignoring a patient's concerns: Always listen to your patient if they question a medication or dose.

5. Now Try It

Choose a common medication you might administer (e.g., insulin, an antibiotic, a blood pressure medication). Research its key pharmacokinetic (ADME) and pharmacodynamic properties. Then, write out the steps you would take to safely administer this medication to a hypothetical patient, explicitly listing how you'd apply each of the 10 Rights of Medication Administration.

Success looks like you being able to clearly articulate the drug's journey through the body and its effects, along with a detailed, step-by-step administration plan that incorporates all 10 Rights.