NURS 6630 Week 2 Explain the Agonist-to-Antagonist Spectrum of Action of Psychopharmacologic Agents

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NURS 6630 Week 2 Explain the Agonist-to-Antagonist Spectrum of Action of Psychopharmacologic Agents Example 1

  1. Explain the agonist-to-antagonist spectrum of action of psychopharmacologic agents, including how partial and inverse agonist functionality may impact the efficacy of psychopharmacologic treatments.

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A full agonist induces a conformational change that turns on signal transduction to the full extent. A partial agonist acts, to a lesser extent, somewhat like an agonist. An antagonist brings about a conformational change that stabilizes the receptor in the baseline state, rendering it “silent.” When agonists or partial agonists are present, the antagonist makes the receptor revert to the baseline state, leading to a reversal in their actions. On the other hand, an inverse agonist causes a conformational change that stops all activities, including the baseline actions (Stahl, 2021). The functionality of the inverse and partial agonists may influence the efficacy of psychopharmacologic treatments, as they may produce less or opposite effects when compared with full agonists.

  1. Compare and contrast the actions of g couple proteins and ion-gated channels.

G couple proteins (GPCR) are a family of transmembrane receptors that lead to the activation of signaling pathways through the G proteins. The activation of the downstream signaling pathways is brought on by the binding of the ligand to a GPCR that then activates the G protein (Stahl, 2021). On the other hand, the ion-gated channels, transmembrane proteins, allow the passage of ions through the membrane when a ligand binds with a receptor. The binding of a ligand to an ion-gated receptor leads to a conformational change that opens the channels, causing ions to flow through it.

The critical distinction between the g couple proteins and the ion-gated channels is the speed of their action; GPCRs lead to the activation of signaling pathways that only take seconds to minutes to lead to a response, while ion-gated channels take milliseconds to respond. Another distinction is the type of signaling pathway that is activated by each of them. The GPCRs lead to the activation of the intracellular signaling pathways that influence changes in gene expression; on the other hand, the ion-gated channels directly affect membrane potential changes. Despite these differences, ion-gated channels and GPCRs are vital targets for most psychopharmacologic agents. For many drugs to modulate intracellular signaling pathways, they must act on GPCRs, while others work on the ion-gated channels to modulate the excitability of neurons and membrane potential.

  1. Explain how the role of epigenetics may contribute to pharmacologic action.

Epigenetics refers to how gene expression occurs without changes to the underlying DNA sequences. Several factors can influence these changes, such as pharmacologic agents, stress, and environmental exposures (Stahl, 2021). Pharmacologic agents can alter the activity of the enzymes that act on DNA and histones, the proteins that package the DNA to a composite structure, thus influencing epigenetics. For instance, some drugs that add methyl groups to the underlying DNA can cause gene expression changes, while some medications that cause the removal of ethyl groups from the histones can also lead to these changes. Changes in epigenetics can influence some drugs’ pharmacologic actions by altering the genes involved with their mechanism of action (Stahl, 2021). For example, the drugs that target the receptor may alter the expression of the downstream genes of the receptor, causing neuronal function changes. Epigenetics has also been associated with the development of tolerance or dependence on certain drugs.

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  1. Explain how this information may impact the way you prescribe medications to patients. Include a specific example of a situation or case with a patient in which the psychiatric mental health nurse practitioner must be aware of the medication’s action.

Understanding the agonist-to-antagonist action of the psychopharmacologic agents and the differences between the ion-gated channels and the G couple proteins is essential to help one make informed decisions when attending to patients under these medications. For instance, when taking care of a patient suffering from anxiety, this knowledge can help one to prescribe full agonist medications that cause a maximal response to help reduce the symptoms quickly. On the other hand, if the patient is only experiencing mild symptoms, it may be prudent to prescribe a partial agonist to produce a favorable response to the patient. Understanding epigenetics can help a nurse anticipate certain side effects in specific patients. For example, when looking after a patient with a family history of addiction, this knowledge can help one to be cautious not to prescribe medications that have been established to lead to addiction, such as benzodiazepines and opioids.

One specific instance where the knowledge of the mechanism of action may come in handy is when taking care of a patient diagnosed with depression. Depression is commonly treated with selective serotonin reuptake inhibitors (SSRIs) that work through the blockage of serotonin reuptake, a neurotransmitter responsible for the regulation of mood. However, certain side effects have been associated with their use, such as gain of weight and sexual dysfunction that may be related to changes caused by epigenetics in genes that regulate sexual function and body metabolism. Therefore, a nurse must be aware of these potential side effects and monitor patients closely for any changes in sexual function and weight when taking SSRIs.

NURS 6630 Week 2 Explain the Agonist-to-Antagonist Spectrum of Action of Psychopharmacologic Agents References

Stahl, S. M. (2021). Stahl’s essential psychopharmacology: Neuroscientific basis and practical applications (5th Ed.) Cambridge University Press. https://www.cambridge.org/us/universitypress/subjects/medicine/mental-health-psychiatry-and-clinical-psychology/stahls-essential-psychopharmacology-neuroscientific-basis-and-practical-applications-5th-edition?format=PB&isbn=9781108971638#:~:text=%E2%80%98Stahl%E2%80%99s%20Essential%20Psychopharmacology%20is

NURS 6630 Week 2 Explain the Agonist-to-Antagonist Spectrum of Action of Psychopharmacologic Agents Sample Solution Included

Foundational Neuroscience

As a psychiatric and mental health nurse practitioner, it is essential for you to have a strong background in foundational neuroscience. In order to diagnose and treat patients, you must not only understand the pathophysiology of psychiatric disorders but also how medications for these disorders impact the central nervous system. These concepts of foundational neuroscience can be challenging to understand. Therefore, this Discussion is designed to encourage you to think through these concepts, develop a rationale for your thinking, and deepen your understanding by interacting with your colleagues.

For this Discussion, review the Learning Resources and reflect on the concepts of foundational neuroscience as they might apply to your role as the psychiatric mental health nurse practitioner in prescribing medications for patients. 

BY DAY 3 OF WEEK 2

Post a response to each of the following:

  1. Explain the agonist-to-antagonist spectrum of action of psychopharmacologic agents, including how partial and inverse agonist functionality may impact the efficacy of psychopharmacologic treatments.
  2. Compare and contrast the actions of g couple proteins and ion gated channels.
  3. Explain how the role of epigenetics may contribute to pharmacologic action.
  4. Explain how this information may impact the way you prescribe medications to patients. Include a specific example of a situation or case with a patient in which the psychiatric mental health nurse practitioner must be aware of the medication’s action.

Upload a copy of your discussion writing to the draft Turnitin for plagiarism check.  Your faculty holds the academic freedom to not accept your work and grade at a zero if your work is not uploaded as a draft submission to Turnitin as instructed.

Read a selection of your colleagues’ responses.

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BY DAY 6 OF WEEK 2

Respond to at least two of your colleagues on two different days in one of the following ways:

  • If your colleagues’ posts influenced your understanding of these concepts, be sure to share how and why. Include additional insights you gained.
  • If you think your colleagues might have misunderstood these concepts, offer your alternative perspective and be sure to provide an explanation for them. Include resources to support your perspective.

Note: For this Discussion, you are required to complete your initial post before you will be able to view and respond to your colleagues’ postings. Begin by clicking on the Reply button to complete your initial post. Remember, once you click on Post Reply, you cannot delete or edit your own posts and you cannot post anonymously. Please check your post carefully before clicking on Post Reply! 

NURS 6630 WEEK 4 ASSIGNMENT – ASSESSING AND TREATING VULNERABLE POPULATIONS FOR DEPRESSIVE DISORDERS

TO PREPARE FOR THIS ASSIGNMENT:

  • Review this week’s Learning Resources, including the Medication Resources indicated for this week.
  • Reflect on the psychopharmacologic treatments you might recommend for the assessment and treatment of vulnerable patient populations requiring antidepressant therapy.

THE ASSIGNMENT: 5 PAGES

For this assignment, you will develop a patient medication guide for treatment of depressive disorders in a vulnerable population (your choice for one vulnerable patient population to choose from: children, adolescents, older adults, dementia patients, pregnant women or one not listed of your choice!). Be sure to use language appropriate for your audience (patient, caregiver, parent, etc.).

You will include non-copyright images and/or information tables to make your patient medication guide interesting and appealing. Limit your patient medication guide to 5 pages. You will create this guide as an assignment; therefore, a title page, introduction, conclusion, and reference page are required. You must include a minimum of 3 scholarly supporting resources outside of your course provided resources.

In your patient guide, include discussion on the following:

  • Depressive disorder causes and symptoms
  • How depression is diagnosed for the vulnerable population of your choice, why is this population considered vulnerable
  • Medication treatment options including risk vs benefits; side effects; FDA approvals for the vulnerable population of your choice
  • Medication considerations of medication examples prescribed (see last bullet item)
  • What is important to monitor in terms of labs, comorbid medical issues with why important for monitoring
  • Special Considerations (you must be specific, not general and address at least one for EACH category; you must demonstrate critical thinking beyond basics of HIPPA and informed consent!): legal considerations, ethical considerations, cultural considerations, social determinants of health
  • Where to follow up in your local community for further information
  • Provide 3 examples of how to write a proper prescription that you would provide to the patient or transmit to the pharmacy. 

Note: Support your rationale with a minimum of five academic resources. While you may use the course text to support your rationale, it will not count toward the resource requirement. You should be utilizing the primary and secondary literature.

Reminder: The College of Nursing requires that all papers submitted include a title page, introduction, summary, and references. The Sample Paper provided at the Walden Writing Center provides an example of those required elements (available at https://academicguides.waldenu.edu/writingcenter/templates/general#s-lg-box-20293632).

All papers submitted must use this formatting.

LEARNING RESOURCES

Required Readings

Medication Resources

Note: To access the following medications, use the Drugs@FDA resource. Type the name of each medication in the keyword search bar. Select the hyperlink related to the medication name you searched. Review the supplements provided and select the package label resource file associated with the medication you searched. If a label is not available, you may need to conduct a general search outside of this resource provided. Be sure to review the label information for each medication as this information will be helpful for your review in preparation for your Assignments.

Review the following medications:

  • bupropion
  • citalopram
  • clomipramine
  • desipramine
  • desvenlafaxine
  • doxepin
  • duloxetine
  • escitalopram
  • fluoxetine
  • fluvoxamine
  • imipramine
  • ketamine
  • mirtazapine
  • nortriptyline
  • paroxetine
  • selegiline
  • sertraline
  • trazodone
  • venlafaxine
  • vilazodone
  • vortioxetine

Required Media

Optional Resources

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NURS 6630 Week 9 A Young Girl With ADHD

NURS 6630 Week 2 Explain the Agonist-to-Antagonist Spectrum of Action of Psychopharmacologic Agents Example Solution

Neurotransmitters and Receptor Theory

Neurotransmitters mediate the transmission of electrical impulses from one neuron to another. Multiple neurotransmitters are involved in central nervous system function, including amines (catecholamines, acetylcholine, and serotonin), amino acids (GABA, aspartate, and glutamate), peptides (neuropeptide Y), and gases such as nitric oxide (Sheffler et al., 2022). As discussed further, psychopharmacologic medications bind to specific neurotransmitter receptors, either activating (agonistic) or inhibiting (antagonistic).

Agonist-to-Antagonist Spectrum of Action of Psychopharmacologic Agents

Psychopharmacologic agents are useful in the treatment of a variety of psychiatric disorders, including mood disorders, trauma and stressor disorders, behavioral disorders, and psychotic disorders. The drugs exhibit either agonistic or antagonistic activity when acting at the receptor site. Whereas agonists bind to and activate a receptor to produce specific actions, antagonists bind to and block specific actions or responses (Katzung, 2018; Stern et al., 2015). The dopamine hypothesis, for example, is widely accepted in the etiology of schizophrenia. 

Excessive dopaminergic transmission is thought to be responsible for schizophrenic symptoms, and research has found higher levels of dopaminergic receptors in schizophrenic patients (Stahl, 2018). This epiphany is why psychopharmacologic agents that block Dopamine receptors, such as chlorpromazine, are used to treat schizophrenia. In contrast, neurodegenerative disease such as Parkinson’s Disease (PD) has been linked to decreased dopamine levels and receptors, which is why dopamine agonists such as Levodopa are used to treat it.

Partial agonists bind to and activate receptors but have only partial efficacy. Partial agonists exhibit both agonistic and antagonistic actions, such as Buspirone, a partial agonist for 5HTA1 receptors and an antagonist for D2 receptors (Katzung, 2018). As a result, Buspirone can be used as both an anxiolytic and an antidepressant medication. Conversely, inverse agonists bind to receptors to produce effects opposite to those of the agonist (Katzung, 2018). Naltrexone is an example of a partial inverse agonist that is used to treat opioid addiction.

G-coupled Proteins and Ion-gated Channels

G-coupled proteins and Ion-gated chandelles are both cell surface receptors. To release ions, ligand-gated ion channels are controlled by neurotransmitters, whereas G-coupled receptors are entirely dependent on the second messenger system (Miller & Lappin, 2022). Because of the differences in stimulation mechanisms, the receptors take varying amounts of time to activate.

While ligand-gated ion channels are activated in milliseconds, G-coupled protein receptors take seconds (Miller & Lappin, 2022). Furthermore, nicotinic acetylcholine receptors and GABA A receptors are examples of ligand-gated ion channels, whereas G-coupled receptors include muscarinic acetylcholine receptors and adrenoceptors (Katzung, 2018; Miller & Lappin, 2020). Regardless of the differences, receptors are critical in carrying out physiologic functions at the molecular level.

Role of Epigenetics in Pharmacologic Action

Genes play an essential role in the body but so do the behaviors and environment.  Epigenetics is the study of how behavior and environment influence gene expression (CDC, 2022). Unlike genetic changes, epigenetic changes are reversible and alter how the body reads the DNA sequence rather than changing the DNA sequence itself. The epigenetic changes may influence the pharmacology of certain drugs. 

Brain-Derived Neurotrophic Factor (BDNF), for example, promotes neuronal survival and synaptic plasticity and is involved in learning, memory, and neurotransmitter release (Webb et al., 2020). BDNF is expressed differently across brain regions depending on environmental stressors, ushering in the concept of epigenetics. Human studies show that BDNF brain levels decrease in untreated major depressive illness and increase with antidepressant treatment (Webb et al., 2020). As a result, BDNF has emerged as a viable candidate for predicting response to antidepressant therapy.

Significance of the Information

Information regarding the pharmacology of drugs is critical in healthcare. In addition to understanding disease mechanisms, psychiatric mental health nurse practitioners (PMHNP) must be proficient in drug pharmacology knowledge. For example, in the etiology of PD, the PMHNP is aware of the link between the disease and Dopamine. As a result, a PMHNP may decide to prescribe a Dopamine agonist, such as Levodopa, rather than a Dopamine antagonist, which would worsen the symptoms. 

Additionally, the pharmacology of a drug allows PMHNPs to understand the potential side effects of a drug. In the treatment of schizophrenia, for example, 12.5-50 mg of Risperidone may be injected into the deltoid or gluteal muscle every two weeks (McNeil et al., 2022), and a nurse should be aware that it is capable of causing extrapyramidal side effects, so the treatment should be used with caution. The information thus improves the way nurses perform their duties, resulting in better patient outcomes.

Conclusion

It is imperative for a PMHNP to have a concrete background in neuroscience. Understanding the pathophysiology of the disease is important in treating psychiatric patients, but knowledge of the medications used to treat the conditions is far more critical. This enables PMHNPs to practice competently and with full practice authority, even in the absence of a supervising psychiatrist consultant. While foundational neuroscience can be difficult to grasp, interacting with colleagues and patients broadens one’s understanding and alleviates the agony of trying to decipher difficult concepts.

References

CDC. (2022, August 15). What is epigenetics? Centers for Disease Control and Prevention. https://www.cdc.gov/genomics/disease/epigenetics.htm

Katzung, B. G. (2018). Basic & Clinical Pharmacology. Basic & Clinical Pharmacology.

McNeil, S. E., Gibbons, J. R., & Cogburn, M. (2022). Risperidone. In StatPearls [Internet]. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK459313/

Miller, E. J., & Lappin, S. L. (2022). Physiology, Cellular Receptor. In StatPearls [Internet]. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK554403/

Sheffler, Z. M., Reddy, V., & Pillarisetty, L. S. (2022). Physiology, Neurotransmitters. In StatPearls [Internet]. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK539894/

Stahl, S. M. (2018). Beyond the dopamine hypothesis of schizophrenia to three neural networks of psychosis: dopamine, serotonin, and glutamate. CNS Spectrums, 23(3), 187–191. https://doi.org/10.1017/S1092852918001013

Stern, T. A., Fava, M., Wilens, T. E., & Rosenbaum, J. F. (2015). Massachusetts general hospital psychopharmacology and neurotherapeutics. Elsevier Health Sciences.

Webb, L. M., Phillips, K. E., Ho, M. C., Veldic, M., & Blacker, C. J. (2020). The relationship between DNA methylation and antidepressant medications: A systematic review. International Journal of Molecular Sciences, 21(3), 826. https://doi.org/10.3390/ijms21030826

NURS 6630 Week 3: Concepts in Assessing Medication Adherence and Strategies To Mitigate Non-Adherence

Self Assessment QUIZ

Question 1 0 pts

Introducing adherence in facilitating treatment goals is something that would be necessary in a patient who has previously displayed nonadherence patterns.

Group of answer choices

True

False

Question 2 0 pts

G-protein coupled receptors are targets for several psychiatric medications. Given what we know about these receptors, what is the ultimate result we will see when one of them is activated in a way that would potentiate an action?

Group of answer choices

A. Intracellular activation of second messengers

B. Protein phosphorylation

C. Modification of gene expression

Question 3 0 pts

Which neurotransmitter is considered the major excitatory neurotransmitter?

Group of answer choices

A. Glycine

B. GABA

C. Glutamate

D. Serotonin

Question 4 0 pts

G-protein coupled receptors are examples of what type of effector pathway?

Group of answer choices

A. Slow effector pathways

B. Rapid effector pathways

C. NMDA glutamate receptor pathways

D. Modulated effector pathways

Question 5 0 pts

Of the components of patient-focused interventions to enhance adherence, which component includes the following strategies: adaptive thinking, use of cues, and support?

Group of answer choices

Motivation

Skills

Logistics

Education

Question 6 0 pts

Motivation is a component of patient-focused interventions to enhance adherence. Based on the transtheoretical model, readiness to change can fluctuate across five stages. Which stage is represented by the patient who is aware that a problem exists and, while seriously thinking about overcoming it, has not yet committed to a plan of action?

Group of answer choices

Preparation

Action

Contemplation

Maintenance

Question 7 0 pts

The human brain is subcategorized into four major structures. These structures include the cerebral cortex, brainstem, subcortical structures, and the cerebellum. Of these major categories, which one houses the area of the brain that has been found in some neuropathological studies of patients with schizophrenia to be of smaller size?

Group of answer choices

Cerebral cortex

Brainstem

Subcortical structures

Cerebellum

Question 8 0 pts

Neurotransmitters are defined by four essential characteristics. These are:

Group of answer choices

A. Neurotransmitters are synthesized within presynaptic neurons.

B. Depolarization of a neuron results in the release of a neurotransmitter, which exerts a multitude of actions on the postsynaptic neuron.

C. Their action on postsynaptic neurons can be replicated by administering a drug that mimics the activity of the endogenous neurotransmitter.

D. Their action in the synaptic cleft is terminated by a specific action.

E. A, C, and D only

Question 9 0 pts

Serotonin (5HT) is a neurotransmitter associated with mood, sleep, and psychosis. There are several serotonin receptors all over the human body. A unique aspect of the second generation antipsychotics is their ability to block 5HT2a receptors. What is the effect of this inhibition?

Group of answer choices

A. Stabilizes dopamine concentrations in the CNS

B. Induces anxiety

C. Causes hallucinations

D. Reduces platelet function

Question 10 0 pts

Treatment adherence is affected by several different factors. Clinical factors include mood, anxiety, psychosis, and substance misuse. There are also patient factors such as knowledge, attitude, and beliefs; economic and racial/ethnic disparities, and clinical encounters. A patient who presents hopeless, with decreased energy, and poor concentration is affected by which factor?

Group of answer choices

Substance misuse

Knowledge deficits

Attitude ad belief system

Mood

Question 11 0 pts

A patient arrives in the ED via EMS having a grand mal seizure. The ED physician instructs the RN to give 10 milligrams of Diazepam IV X1 dose STAT. The patient’s seizure breaks within 2 minutes of the Diazepam being administered. The mechanism by which this medication causes rapid resolution of seizure activity is via which receptor type (effector pathway/receptor subtype)?

Group of answer choices

A. Slow effector pathways/G-protein coupled receptor

B. Slow effector pathway/ion channel

C. Rapid effector pathways/G-protein coupled receptor

D. Rapid effector pathway/ion channel

Question 12 0 pts

Neurotransmission is unidirectional insofar as chemical and electrical conduction is concerned within the individual neuron. Of the following descriptions, which best characterizes the order of neurotransmitter/receptor interaction that results in an electrical signal impulse and the release of another neurotransmitter for interaction in the synaptic cleft (signal conduction through a neuron)?

Group of answer choices

Cell body, dendrites, Axon, Axon terminals

Dendrites, Axon, Cell body, Axon, Axon terminals

Dendrites, Cell body, Axon, Axon terminals

Axon terminals, Axon, Cell body, Dendrites

Question 15 0 pts

If a patient admits to taking his medication every other day (instead of daily, as prescribed), a potential concern would be:

Group of answer choices

A. Sufficient understanding or acceptance of the illness

B. Abuse of the medication

C. Expense

D. Is the desired effect recognized at a lower daily dose?

Question 16 0 pts

Receptors trigger one of two effector pathways resulting in changes in neuronal activity. These changes will, ultimately, effect gene expression. Which effector pathway is characterized by ion flux through transmitter-activated channels resulting in an altered membrane potential and neuronal activity?

Group of answer choices

A. Slow effector pathways

B. Modulated effector pathways

C. Rapid effector pathways

D. NMDA glutamate receptor pathways

Question 17 0 pts

Upon blocking a Serotonin reuptake pump, what happens in the synaptic cleft and on the post synaptic cell membrane?

Group of answer choices

A. The result will be an increase in available Serotonin in the synaptic cleft causing the post synaptic cell to increase the number of Serotonin receptors.

B. The result will be an increase in the available Serotonin in the synaptic cleft causing the post synaptic neuron to reduce the number of Serotonin receptors.

C. The result will be an increase in Serotonin in the synaptic cleft resulting in an increase in reuptake pumps on the presynaptic neuron.

D. The result will be an increase in Serotonin in the synaptic cleft resulting in a decrease in reuptake pumps on the pre-synaptic neuron.

Question 18 0 pts

When dopamine (subtype 2) receptors are blocked in this pathway (system), it is evident by EPS.

Group of answer choices

A. Mesocortical

B. Tuberoinfundibular

C. Nigrostriatal

D. Mesolimbic

Question 19 0 pts

Which of the following consists of all the known major neurotransmitters that are relevant in psychiatry?

Group of answer choices

glutamate, GABA, dopamine, serotonin, norepinephrine, histamine, steroids, nitric oxide

glutamate, GABA, dopamine, norepinephrine, serotonin, acetylcholine, histamine, endogenous opioids, steroids, cannabinoids, nitric oxide

glutamate, GABA, dopamine, serotonin, acetylcholine, endogenous opioids, nitric oxide, cannabinoids, steroids

glutamate, GABA, dopamine, serotonin, norepinephrine, endogenous opioids, steroids, histamine, nitric oxide

Question 20 0 pts

Glia cells play a supportive role to the neuron. A few of the functions of the glial cells include providing nutrition, maintaining homeostasis, stabilizing synapses, and myelinating axons. The glial cells are categorized as microglia and macroglia. Of these two cell types, which one plays an active and critical role in glutamatergic neurotransmission by providing a co-agonist required for glutamate receptor function?

Group of answer choices

microglial

macroglial

Also Read: NURS 6521 Week 6 Decision Tree for Neurologic and Musculoskeletal Disorders