Pharmacodynamics

[Virtual Presenter] Good morning everyone. Today, we'll be discussing pharmacodynamics and how it relates to nursing care. We'll be looking at drug actions, agonists, antagonists, efficacy, potency, and therapeutic index, which are all important terms related to pharmacodynamics and will be beneficial to know for nurses when caring for patients. Let's begin..

[Audio] Pharmacodynamics is the branch of pharmacology focusing on the effects of drugs on the body, considering the mechanism of action, the site of action, and the biochemical and physiological pathways of the drug. Exploring their interaction has crucial implications for understanding how to treat and prevent diseases..

[Audio] Half-life of a drug or substance is a crucial metric to assess its activity over a certain time period. It is the interval needed for the body to dispose of half of the drug concentration. When prescribing drugs, one must keep an eye on the half-life as to avoid potential harmful reactions or toxicity. The National Institute of Health has issued regulations on the account of half-life when administering drugs..

[Audio] Pharmacodynamics is an important topic for nurses to understand, as it focuses on how drugs interact with living systems. This includes looking at the type of drug, its dose, route of administration, frequency, and metabolism. By learning and understanding how drugs act and affect the body, it allows nurses to provide more informed and effective treatments to their patients..

[Audio] Pharmacodynamics is a vital area of study for nurses as it sheds light on how drugs will interact with our patients' bodies. This knowledge allows us to keep a close eye on any side effects or adverse reactions and have confidence in the effects the drug will have on our patients, providing them with the best care possible..

[Audio] When studying pharmacodynamics, there are several key terminologies to be aware of. An agonist is a type of drug that activates certain receptors in the body, whilst an antagonist is a drug that blocks the action of another drug or inhibits a receptor. Efficacy and potency provide us with a measure of how strong and effective a drug is, whilst the therapeutic index allows us to measure the safety of a drug..

[Audio] Agonists and antagonists are two types of drugs that act on receptors in the body. Agonists are drugs that activate the receptors, like a key that unlocks a lock. Antagonists, however, bind to the receptor but don't activate it, like a key that fits the lock but doesn't turn it. This prevents the agonist from activating the receptor..

[Audio] Agonists and antagonists are important components of pharmacodynamics, which is the study of how drugs interact with our bodies. An agonist is a substance that binds to a receptor and produces a full activation of the target receptor, while an antagonist binds to a receptor and results in less or no activation. By understanding the relationship between agonists and antagonists, we can better understand how the body responds to different drugs..

[Audio] Quote: "Agonists and Antagonists. An example of an agonist is morphine, which activates opioid receptors to reduce pain. An example of an antagonist is naloxone, which blocks opioid receptors and is used in opioid overdoses." Understanding these concepts can help us to choose the right medication and dose. Efficacy is the ability of a drug to produce a desired result and its potency is the amount of the drug that is needed to produce an effect..

[Audio] It is essential to recognize the distinction between efficacy and potency when deciding on medications and deciding the right dose. Efficacy is the level of response a drug can offer; it is the biggest impact the drug can create. Potency is, however, the amount of drug essential to create a required effect. A drug of high potency will require a lower dose of the same medication to generate the identical effect as a drug of lower potency. Making sure to distinguish between efficacy and potency enables us to select the correct drug and to administer an efficient dosage..

[Audio] Drug B, at 500mg, is significantly less potent than Drug A, but shows to be 50% more efficacious. Consequently, a dose of 50mg of Drug B is required to achieve the same effects as the 5mg of Drug A. Despite needing larger doses, the increased efficacy of Drug B is worth it..

[Audio] The correlation between the dose of a drug and its efficacy is demonstrated in this slide. Three points are observed on the graph: 100, 50, and 0.1, representing high efficacy, low efficacy, and EC50 respectively. It is observed that as the dose of the drug increases, its efficacy increases as well. This gives an indication of how doses of drugs interact with the body to produce their desired effects..

[Audio] The relationship between the dose of a drug or other agent and its biological response is illustrated by dose-response curves. Starting from low concentrations, the response gradually increases up to a maximum response, afterwards decreasing as the response becomes saturated. EC50 is the concentration at which the response is half of the maximum response; drugs with high potency have a low EC50, whereas those with low potency have a high EC50. This dose-response curve demonstrates that increasing potency, or reducing EC50, will result in a greater response given a fixed drug concentration..

[Audio] It is imperative that nurses be aware of the Therapeutic Index, as it is a key measure of safety for our patients. The Therapeutic Index is a ratio between the toxic and therapeutic doses of a drug. Knowing this ratio allows us to have a wider gap between therapeutic and toxic doses, thus ensuring our patients are safe. A high Therapeutic Index indicates a higher level of safety for our patients, and it is our responsibility to make sure they remain safe; understanding the Therapeutic Index is an integral part of this..

CD 0/009 peue O!XOI asoa xepu! onnedæeqx onnedeueqx.

[Audio] The graph plots a concentration of the drug in the plasma, from 4- 40 mg/L, and on the Y-axis, it shows the therapeutic index, efficacy, and toxicity of the drug. The graph indicates that a therapeutic window exists when the concentration is between 20-60 mg/L. It can be seen that the drug will have the optimal therapeutic index, with no toxicity or loss of efficacy, when the concentration of the drug is at the optimal therapeutic window..

[Audio] Acetaminophen, also known as paracetamol, is a widely used medication. Its efficacy relies on the correct dosage being taken; however, its misuse can be hazardous. A single dose of 10 grams of acetaminophen is considered to be toxic in an adult, whereas the typical therapeutic single dose is 500 milligrams, resulting in a therapeutic ratio or index of 20..

[Audio] Drug interactions are an important factor in assessing the efficacy of treatments. When two drugs are used concurrently, their pharmacodynamic properties can interact either synergistically, leading to a greater effect than either drug alone, or antagonistically, reducing the effect of the other drug. It is essential to take these interactions into consideration when deciding upon a treatment..

[Audio] Considering pharmacodynamics, it is essential to contemplate the diverse effects of drug combinations. For instance, trimethoprim and sulfamethoxazole synergistically taken together can generate the Bactrim medication and combining amoxicillin and clavulanic acid can result in the Augmentin medication. In contrast, combining morphine with naloxone can create an antagonistic effect..

[Audio] The reaction of the body to drugs is continually changing. Patients can become tolerant to particular drugs, necessitating increased doses to achieve the same result. Checking this carefully is essential as it could require modifying the dosage or the medication to get the wanted outcome. Knowing this kind of change is key in order to give the highest quality of care..

[Audio] When administering drugs, tolerance and sensitivity must be taken into account. Certain patients may be particularly sensitive to certain drugs which can lead to effects, including side effects, at lower doses, resulting in the need for extra care. Responses to drugs are individualized, therefore it is important to factor in each patient's characteristics when providing treatments as individual responses can differ significantly..

[Audio] Nurses should possess a good understanding of pharmacodynamics in order to provide the highest quality of care for their patients. Knowing the possible effects, side effects, and interactions of drugs is necessary in order to explain them to patients, ensuring they get the best possible results from their medications while minimizing the risk of any adverse effects. Pharmacodynamics can therefore play a crucial role in patient care..

[Audio] Understanding the pharmacologic properties of drugs is essential for nurses in order to provide the best care for our patients. Pharmacodynamics studies the biochemical and physiological effects of drugs and their mechanisms of action, so nurses must be familiar with these concepts in order to develop an effective plan of care. This knowledge will help ensure that our patients receive the best possible care..