Pharmacology and Drug Administration Principles

Introduction to Pharmacology and Medication Naming

Pharmacology is defined as the study of medications and their effects upon the human body.

Medication Naming Classifications

Every medication is classified under three distinct naming conventions:

• Brand Name / Trade Name:

  • The proprietary name under which a drug is marketed and sold by a manufacturer.

  • Designated on packaging with a registered trademark symbol ($\text{\textregistered}$ or an $r$ in a circle), indicating exclusive legal rights to sell the product name.

  • Brand names are always capitalized in written text, medical questions, and examination prompts (e.g., Advil, Motrin, Bayer, Proventil, Ventolin, EpiPen, Narcan).

  • Brand name products carry a significantly higher retail cost due to marketing, packaging, and proprietary rights, despite containing identical active ingredients to generic versions.

• Generic Name:

  • The official non-proprietary chemical name assigned to a drug (e.g., ibuprofen, aspirin, albuterol, epinephrine, naloxone).

  • Unless located at the beginning of a sentence, generic names are written in lowercase letters.

• Official Name:

  • The standard designation listed in official pharmacopoeial publications.

  • Indicated by the suffix USP (United States Pharmacopoeia) following the generic name (e.g., ibuprofen USP, oxygen USP, albuterol sulfate USP, epinephrine USP, naloxone hydrochloride USP).

Comparative Naming Examples

• Advil: A brand/trade name product priced at $\$6.99$. The active ingredient panel on the back reads: Each tablet contains $200\,\text{mg}$ of ibuprofen USP.

• Safeway Brand Ibuprofen: A generic/store-brand product priced at $\$2.99$. The active ingredient panel on the back reads: Each tablet contains $200\,\text{mg}$ of ibuprofen USP.

• Costco Bulk Ibuprofen: Generic packaging supplied in coffee-can quantities priced at $\$12.00$ for $5\,000$ tablets. The active ingredient panel reads: Each tablet contains $200\,\text{mg}$ of ibuprofen USP.

• Motrin: A brand/trade name product priced at $\$7.99$. Features a candy-coated exterior costing an additional dollar over Advil, yet contains the identical active formulation: $200\,\text{mg}$ of ibuprofen USP.

The sole operational differences between brand name and generic products are packaging and retail cost. The chemical composition, active ingredient dosage, and physiological action are identical.

United States Pharmacopoeia (USP)

• The United States Pharmacopoeia (USP) serves as the official recipe book and quality standards compendium for medication manufacturing in the United States.

• The designation of USP behind a medication name guarantees that the contents meet federal manufacturing and purity standards.

• Historical Context: Prior to regulatory mandates established around $1906$ to $1910$, pharmacology was entirely unregulated. Unrestricted substances such as liquid morphine, heroin, and cocaine were sold over the counter at local general stores in places like downtown Grass Valley. Package directions were arbitrary (e.g., give 1 to 2 drops every 10 minutes as needed).

Medical Grade Oxygen USP

• Medical oxygen stored in transport cylinders is classified as an official medication requiring a prescription to be filled by medical supply vendors.

• Purity Standards:

  • Medical Grade Oxygen USP: Must maintain a minimum purity concentration of $99.5\%$ pure oxygen.

  • Industrial Grade Oxygen: Used in metal shops for cutting torches; maintains a purity concentration of $95\%$ pure oxygen.

Bioavailability and Routes of Medication Administration

Bioavailability

Bioavailability is defined as the exact percentage of an administered medication or substance that successfully enters the systemic blood circulation.

Routes of Administration

• Intravenous (IV):

  • Medication administered directly into a vein via a catheter hooked to standard normal saline solution.

  • Bioavailability: $100\%$ (serves as the reference benchmark for all routes).

  • Speed of Onset: Immediate/Instantaneous.

• Interosseous (IO):

  • Medication administered directly into the medullary cavity of a bone using a heavy-duty manual needle or battery-powered drill (e.g., proximal humerus, femur, or tibia).

  • Mechanism: Long bones connect directly to the circulatory system via arterial and venous channels.

  • Bioavailability: Equivalent to IV ($100\%$).

  • Speed of Onset: Extremely rapid; marginally slower than direct IV.

  • Indications: Utilized when IV access is difficult or unachievable during critical emergencies (e.g., a severe $10\text{-month-old}$ infant suffering from life-threatening dehydration, or adult cardiac arrest calls requiring instant central circulation access).

• Intramuscular (IM):

  • Medication injected deep into rich muscular tissue.

  • Technique: Needle inserted at a $90^\circ$ angle, penetrating $1\frac{1}{4}$ to $1\frac{1}{2}$ inches into large muscle bodies with high vascularity.

  • Bioavailability: High.

  • Speed of Onset: Medium to fast absorption.

• Subcutaneous (SQ / Sub-Q):

  • Medication injected directly into the adipose/fatty layer beneath the skin.

  • Technique: Short $\frac{1}{2}\,\text{inch}$ needle inserted at a $45^\circ$ angle.

  • Bioavailability / Speed: Slower absorption due to poor blood perfusion in adipose tissue.

  • EMS Application: Not currently utilized in standard prehospital emergency protocols.

• Intranasal (IN):

  • Medication atomized into a fine mist and delivered directly onto the vascularized nasal mucosa.

  • Bioavailability: Extremely high depending on drug volume, pH, and chemical properties (e.g., Narcan/naloxone maintaining up to $99\%$ bioavailability; needle-free nasal epinephrine such as Nepi).

• Enteral / Oral Routes (Pie Hole):

  • Sublingual (SL): Medication placed directly under the tongue for rapid mucosal absorption (e.g., Nitroglycerin).

  • Per Os (PO): Medication taken by mouth, chewed, and/or swallowed into the digestive tract (e.g., Aspirin).

  • Buccal: Medication placed in the cheek pocket against oral mucosa (e.g., Oral Glucose under National Registry standards).

• Per Rectum (PR):

  • Medication administered rectally via suppository (e.g., rectal suppositories given by school nurses for pediatric seizure control).

  • Bioavailability: High, due to rich vascularity of rectal mucosa.

• Transdermal:

  • Medication applied topically onto the outer skin surface for slow, continuous systemic absorption through a patch or paste.

• Pulmonary / Inhalation:

  • Medication atomized or aerosolized and inhaled directly into the pulmonary tree (e.g., Albuterol, Medical Oxygen USP).

Metric System and Medical Mathematics

Standard Units of Mass and Volume

• Mass / Weight Units:

  • Gram ($\text{g}$), Milligram ($\text{mg}$), Microgram ($\mu\text{g}$), Kilogram ($\text{kg}$).

  • $1\,\text{kilogram (kg)} = 1\,000\,\text{grams (g)}$.

  • $1\,\text{gram (g)} = 1\,000\,\text{milligrams (mg)}$.

  • $1\,\text{milligram (mg)} = 1\,000\,\text{micrograms (}\mu\text{g)}$.

  • Physical Scale Examples:

    • $1\,\text{kg} \approx 2.2\,\text{lbs}$ (roughly equivalent to a standard shoe or brick).

    • $1\,\text{United States Penny} = 2.6\,\text{grams}$.

    • $1\,\text{mg}$ is equivalent to dividing a penny into $2\,600$ tiny pieces (roughly the mass of a single coarse grain of salt).

• Volume Units:

  • Liter ($\text{L}$), Milliliter ($\text{mL}$).

  • $1\,\text{Liter (L)} = 1\,000\,\text{milliliters (mL)}$.

  • $1\,\text{milliliter (mL)} = 1\,\text{cubic centimeter (cc)}$.

  • Regulatory Formatting Warning: The abbreviation cc is strictly banned from professional healthcare documentation due to high rates of clinical reading errors. Always utilize mL or milliliters in oral and written medical communications.

Patient Weight Conversions

Patient dosing calculations in emergency healthcare are calculated using body mass in kilograms ($\text{kg}$).

• Converting Pounds ($\text{lbs}$) to Kilograms ($\text{kg}$):

  • Formula: $\text{Weight in kg} = \frac{\text{Weight in lbs}}{2.2}$

  • Example: A $154\,\text{lb}$ patient converts to $70\,\text{kg}$ ($154 \div 2.2 = 70$).

• Converting Kilograms ($\text{kg}$) to Pounds ($\text{lbs}$):

  • Formula: $\text{Weight in lbs} = \text{Weight in kg} \times 2.2$

  • Example: A $30\,\text{kg}$ pediatric patient converts to $66\,\text{lbs}$ ($30 \times 2.2 = 66$).

Pharmacological Terminology and Drug Profile Components

Every medication profile consists of standard clinical parameters:

• Dose: The specific mass or volume of medication to be administered to a patient.

• Indication: The specific clinical condition, disease process, or symptom complex justifying medication administration.

• Contraindication: Any clinical situation or condition where a drug must not be given despite an indication being present (e.g., CPAP indicated for severe pulmonary edema, but contraindicated due to a low blood pressure of $80/50\,\text{mmHg}$).

• Route: The anatomical pathway chosen to deliver a medication into the body.

• Action: The specific physiological mechanism or physical change induced by the drug.

• Repeat Dose: Specific clinical protocols detailing the timing and conditions under which a secondary dose may be delivered.

• Precautions: Specific clinical warnings or tactical handling measures to observe before or during drug delivery.

• Side Effects: Foreseen secondary physiological reactions caused by a drug that are separate from the primary therapeutic target.

  • Example: Nitroglycerin administered to relieve angina causes secondary tongue burning and severe headache. If administered intentionally to cause a headache, causing a headache would be defined as its action.

Drug Profiles: Aspirin (ASA)

• Generic Name: Aspirin

• Official Name: Aspirin USP

• Common Abbreviation: ASA (universally recognized in field documentation)

• Trade / Brand Names: Bayer

• Action:

  • Platelet inhibitor.

  • Prevents blood platelets from clumping together (inhibits aggregation), preventing pre-existing coronary arterial clots from enlarging.

  • Does not directly thin the blood (hydration/water alters blood viscosity).

• Indications:

  • Chest pain suggestive of an Acute Myocardial Infarction (AMI).

• Contraindications:

  • Absolute active, uncontrolled internal or external bleeding (e.g., severe traumatic limb amputation via chainsaw concurrent with cardiac chest pain).

  • Inability to swallow (e.g., post-cancer surgical patient with a direct gastric feeding tube receiving liquid nutrition).

  • Note: Elevated blood pressure is not a contraindication.

• Dose and Route:

  • Standard Clinical Dose: $324\,\text{mg}$ chewed and swallowed ($4 \times 81\,\text{mg}$ chewable tablets).

  • Academic/Testing Range: $160\,\text{mg}$ to $325\,\text{mg}$.

  • Preparation: Supplied as $81\,\text{mg}$ chewable tablets. (The term children's aspirin is banned in healthcare; refer strictly to them as $81\,\text{mg}$ chewables). If only a single standard $325\,\text{mg}$ non-chewable adult tablet is available, have the patient chew and swallow it.

• Clinical Priority & Field Management Rules:

  • Aspirin is the most critical intervention for cardiac chest pain. Its prompt administration outweighs taking a blood pressure, establishing IV access, acquiring a 12-lead EKG, placing a patient on oxygen, or transporting to a non-cath hospital (e.g., Sierra Nevada Hospital or Auburn Faith).

  • The sole priority higher than aspirin administration is immediate transport to a designated cardiac catheterization center (e.g., Sutter Roseville or San Juan).

  • Administer aspirin immediately following initial SAMPLE history and OPQRST pain assessment while a partner collects vital signs.

  • Managing Patient Pushback:

    • Patient on prescribed blood thinners (Eliquis, Warfarin): Instruct the patient that today is an exceptional acute medical event and administer the aspirin.

    • Patient claims prior self-medication (e.g., took standard Tylenol/acetaminophen): Clarify exact medication. If uncertainty exists, administer the full dose.

    • Patient took daily $81\,\text{mg}$ aspirin two hours prior: If confirmed as a reliable historian, administer 3 additional $81\,\text{mg}$ tablets ($243\,\text{mg}$) to complete the full $324\,\text{mg}$ therapeutic dosage.

    • Patient claims aspirin allergy due to stomach discomfort: Explain that gastrointestinal upset is a side effect, not an anaphylactic reaction, and administer the medication.

• Repeat Dose: None in the emergency setting ($24\text{-hour}$ dosing cycle).

Drug Profiles: Albuterol Sulfate and Atrovent

Albuterol Sulfate USP

• Generic Name: Albuterol sulfate USP

• Brand / Trade Names: Proventil, Ventolin

• Action:

  • $\beta_2$-specific bronchodilator.

  • Selectively stimulates $\beta_2$-adrenergic receptors within the sympathetic nervous system (fight-or-flight response), relaxing bronchial smooth muscle.

• Indications:

  • Bronchospasm associated with asthma or Chronic Obstructive Pulmonary Disease (COPD).

• Contraindications:

  • None in emergency healthcare settings.

• Precautions & Side Effects:

  • Jitteriness, muscle tremors, nervousness, tachycardia (similar to high caffeine consumption).

• Dose and Route:

  • $1$ to $2$ puffs via Metered Dose Inhaler (MDI), repeated every $5\,\text{minutes}$ as needed. The MDI must be prescribed to and owned by the patient.

• Administration Auxiliaries:

  • Spacer / Chamber: A clear plastic holding reservoir attached between the MDI and the patient's mouth. Allows pediatric or elderly patients with low inspiratory reserve to suspend aerosolized mist and inhale over multiple breaths.

Ipratropium Bromide (Atrovent)

• Generic Name: Ipratropium bromide

• Brand / Trade Name: Atrovent

• Action:

  • Anticholinergic bronchodilator.

  • Blocks cholinergic (parasympathetic) receptors in bronchial smooth muscle, inhibiting bronchoconstriction.

  • Tug-of-War Analogy: In autonomic balance, Albuterol adds a member to the sympathetic bronchodilating team ($\beta_2$ agonist), whereas Atrovent removes a member from the parasympathetic bronchoconstricting team (cholinergic antagonist). Suppressing parasympathetic tone allows sympathetic bronchodilation to predominate.

• Indications:

  • Bronchospasm associated with COPD and asthma.

• Contraindications:

  • None in emergency healthcare settings.

• Dose and Route:

  • $1$ to $2$ puffs via patient-owned MDI, repeated every $5\,\text{minutes}$ as needed.

Drug Profiles: Epinephrine and Naloxone (Narcan)

Epinephrine USP

• Generic Name: Epinephrine USP

• Brand / Trade Names: Adrenalin, EpiPen, EpiPen Jr., Nepi (nasal formulation)

• Action:

  • Naturally occurring hormone and neurotransmitter.

  • Non-selective adrenergic agonist stimulating $\alpha_1$, $\beta_1$, and $\beta_2$ receptors (pure systemic fight-or-flight response):

    • $\alpha_1$: Profound peripheral vasoconstriction.

    • $\beta_1$: Positive cardiac effects (increases heart rate, contractile force, and electrical conduction).

    • $\beta_2$: Potent bronchodilation.

• Indications:

  • EMR Scope: Severe anaphylaxis only.

  • EMT Scope: Severe anaphylaxis and acute asthma/respiratory distress with wheezing.

• Contraindications:

  • None in life-threatening emergency situations (untreated severe asthma or anaphylaxis leads directly to death). Epinephrine cannot cause an allergic reaction as it is endogenously produced.

• Dose and Route:

  • Adult Dose ($\ge 30\,\text{kg}$ or $\ge 66\,\text{lbs}$): $0.3\,\text{mg}$ IM via auto-injector.

  • Pediatric Dose ($< 30\,\text{kg}$ or $< 66\,\text{lbs}$): $0.15\,\text{mg}$ IM via auto-injector.

  • Repeat Dose: Local protocol allows repetition every $20\,\text{minutes}$ as needed.

• Documentation Rule:

  • Always record decimal doses with a leading zero ($0.3\,\text{mg}$, never $.3\,\text{mg}$). Omitting leading zeros causes tenfold medication calculation errors.

Naloxone Hydrochloride USP (Narcan)

• Generic Name: Naloxone hydrochloride USP

• Brand / Trade Name: Narcan

• Action:

  • Narcotic/Opioid antagonist.

  • Competitively binds to opioid receptor sites, reversing and blocking the central nervous system and respiratory depressant effects of narcotics/opiates.

• Indications:

  • Severe respiratory depression or respiratory arrest secondary to suspected opioid/narcotic overdose.

  • Confirmed clinically by reduced respiratory rate/depth accompanied by pinpoint (miotic) pupils.

• Clinical Rules & Field Realities:

  • Administered strictly to restore adequate ventilation, not to treat altered mental status or drug intoxication alone.

  • Naloxone is completely benign and harmless if administered to a patient who has not ingested opioids.

  • Synthetic narcotics often have a longer half-life than naloxone. A patient may relapse into severe respiratory arrest $20\,\text{minutes}$ after receiving naloxone as the antagonist wears off.

• Delivery Devices and Dosages:

  • 1. Prefilled Syringe with MAD (Mucosal Atomizer Device):

    • Concentration: $2\,\text{mg}$ dissolved in $2\,\text{mL}$ of solution ($1\,\text{mg}/1\,\text{mL}$ concentration ratio).

    • Dose & Technique: $2\,\text{mg}$ IN total. Administer exactly $1\,\text{mL}$ into one nostril, then switch and administer $1\,\text{mL}$ into the opposite nostril.

    • Mucosal Bioavailability: Splitting volume prevents mucosal saturation and swallowing. Intranasal (IN) administration yields $99\%$ bioavailability, whereas swallowing liquid Narcan (PO) drops bioavailability to $5\%$.

  • 2. Over-the-Counter Single-Dose Nasal Spray:

    • Concentration: $4\,\text{mg}$ in $0.1\,\text{mL}$ volume.

    • Dose & Technique: $4\,\text{mg}$ IN administered as a single spray into one nostril by depressing the red plunger. Requires no assembly or dosage splitting due to maintaining $\frac{1}{20}\text{th}$ the liquid volume of prefilled syringes.

• Repeat Dose:

  • Repeat dose every $2\,\text{minutes}$ as needed to restore adequate spontaneous ventilation.

• Precautions & Side Effects:

  • Rapid reversal induces acute opioid withdrawal symptoms, agitation, combativeness, nausea, vomiting, and frequent patient denial of illicit substance ingestion.

Questions & Discussion

• Question: What will the skill set evaluation cover for tomorrow?

• Answer: Practical skill evaluations will focus on assessing drug profiles, identification of indications, contraindications, correct dosing math, and proper deployment techniques for emergency medications.