RC 111 3/25

Introduction

• The speaker mentions they are recording at the start of the meeting.

• The speaker's specialty is in adult critical care, not pharmacology.

Pharmacology Overview

• Pharmacology is the study of drug action, encompassing the drug administration, pharmacokinetics, and pharmacodynamics.

• Learning Objectives:

  • Understand principles of pharmacology, including phases of drug action.

Course Structure

• The approach is streamlined with one slide that encompasses key learning objectives.

• Importance of reading the textbook and listening to lectures for comprehension.

Principles of Pharmacology

• Pharmacokinetics:

  • Involves the drug administration phase, how drugs are absorbed, distributed, metabolized, and eliminated.

  • Drug Administration Phase: Refers to how drugs are made available to the body (e.g., inhalation, oral, injections).

Route of Administration Examples:

• Inhalation – Drugs can be administered through aerosols directly to the respiratory tract, allowing for direct targeting and faster onset of action.

  • Discusses advantages such as quicker absorption and fewer systemic side effects.

• Disadvantages include incorrect dosing due to variables like improper use by patients (e.g., misuse of MDIs).

Pharmacokinetics

• Discusses the time course of a drug: deposition based on absorption, distribution, metabolism, and elimination.

• Key Terms:

  • Ionized vs. Non-ionized drugs:

    • Fully ionized drugs have minimal systemic side effects.

    • Non-ionized (lipid-soluble) drugs can diffuse readily into the bloodstream, potentially increasing systemic side effects.

First Pass Effect

• Describes reduction in drug concentration before reaching systemic circulation (e.g., when processed by the liver).

LT Ratio:

• Represents local versus systemic drug availability. A higher ratio indicates better efficacy for targeting the lungs rather than systemic circulation.

Pharmacodynamics

• Refers to how drugs cause effects on the body based on their interaction with receptors.

• Types of receptors:

  • Intracellular receptors and transmembrane receptors that signal the effects of drugs, particularly in the case of respiratory drugs.

Mechanoreceptors and Chemoreceptors

• Different receptors in the airway respond to mechanical stimuli or chemical changes.

  • Examples:

    • Mechanoreceptors respond to lung inflation and stretch, monitoring breathing volume.

    • Chemoreceptors monitor oxygen and CO2 levels to adjust breathing rates.

Autonomic Nervous System

• It regulates functions like heart rate and airway diameter through sympathetic (fight or flight) and parasympathetic (rest and digest) responses.

• Receptors in this system influence smooth muscle contraction.

Adrenergic and Cholinergic Receptors

• Adrenergic receptors react to epinephrine and norepinephrine; include beta and alpha receptors influencing heart rate and smooth muscle relaxation.

• Cholinergic receptors react to acetylcholine, increasing glandular secretions and muscle contractions in the lungs.

Drugs Classification

• Utilization of Drug Classes:

  • Understanding drug classifications (adrenergic, cholinergic, anticholinergic) is crucial for selection and administration of respiratory drugs.

  • Includes noting specific drug types like bronchodilators and their mechanisms of action.

Adverse Effects and Monitoring

• Various adverse effects from respiratory medications should be noted, including possible impact on heart rate and blood pressure. Monitoring is necessary during administration to mitigate significant side effects, like tachycardia from bronchodilators.

Mucus Controlling Agents

• Discussed agents like n-acetylcysteine which decrease mucus viscosity, thus easing airway clearance.

• Important to administer with other bronchial therapies to prevent obstruction.

Inhaled Corticosteroids

• Indicated for controlling inflammation in conditions like asthma and COPD. These corticosteroids act by reducing airway inflammation over time, highlighting their role in patient maintenance.

Non-steroidal Anti-asthma Drugs

• Leakage of immune system response through the use of drugs like leukotriene receptor antagonists (e.g., montelukast) for asthma prevention and management.

Monoclonal Antibodies

• Targeted to provide a prophylactic effect against allergic asthma by inhibiting IgE interaction with mast cells, reducing asthma exacerbations.

Conclusion

• Role of respiratory therapists involves understanding drug classes, modes of administration, adherence to treatment protocols, and assessing patient outcomes.

• Need for ongoing education on medication management is emphasized to improve patient outcomes, particularly in critical care environments.