NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics

, ,

NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics

As an advanced practice nurse assisting physicians in the diagnosis and treatment of disorders, it is important to not only understand the impact of disorders on the body, but also the impact of drug treatments on the body. The relationships between drugs and the body can be described by pharmacokinetics and pharmacodynamics.

BUY A CUSTOM-WRITTEN, PLAGIARISM-FREE PAPER HERE

Pharmacokinetics describes what the body does to the drug through absorption, distribution, metabolism, and excretion, whereas pharmacodynamics describes what the drug does to the body.

Photo Credit: Getty Images/Ingram Publishing

When selecting drugs and determining dosages for patients, it is essential to consider individual patient factors that might impact the patient’s pharmacokinetic and pharmacodynamic processes. These patient factors include genetics, gender, ethnicity, age, behavior (i.e., diet, nutrition, smoking, alcohol, illicit drug abuse), and/or pathophysiological changes due to disease. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.

For this Discussion, you reflect on a case from your past clinical experiences and consider how a patient’s pharmacokinetic and pharmacodynamic processes may alter his or her response to a drug.

To Prepare
  • Review the Resources for this module and consider the principles of pharmacokinetics and pharmacodynamics.
  • Reflect on your experiences, observations, and/or clinical practices from the last 5 years and think about how pharmacokinetic and pharmacodynamic factors altered his or her anticipated response to a drug.
  • Consider factors that might have influenced the patient’s pharmacokinetic and pharmacodynamic processes, such as genetics (including pharmacogenetics), gender, ethnicity, age, behavior, and/or possible pathophysiological changes due to disease.
  • Think about a personalized plan of care based on these influencing factors and patient history in your case study.
By Day 3 of Week 1

Post a description of the patient case from your experiences, observations, and/or clinical practice from the last 5 years. Then, describe factors that might have influenced pharmacokinetic and pharmacodynamic processes of the patient you identified. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics. Finally, explain details of the personalized plan of care that you would develop based on influencing factors and patient history in your case. Be specific and provide examples.

By Day 6 of Week 1

Read a selection of your colleagues’ responses and respond to at least two of your colleagues on two different days by suggesting additional patient factors that might have interfered with the pharmacokinetic and pharmacodynamic processes of the patients they described. In addition, suggest how the personalized plan of care might change if the age of the patient were different and/or if the patient had a comorbid condition, such as renal failure, heart failure, or liver failure. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.

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 “Post to Discussion Question” link, and then select “Create Thread” to complete your initial post. Remember, once you click on Submit, you cannot delete or edit your own posts, and you cannot post anonymously. Please check your post carefully before clicking on Submit!

Week 1: Basic Pharmacotherapeutic Concepts/Ethical and Legal Aspects of Prescribing

How do beta-blockers work? What exactly do antibiotics do to the bacteria they target? What effects does an anti-depressant have on blood flow? NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.

Questions like these are related to the underlying pharmacokinetic and pharmacodynamic processes of pharmacotherapeutics. As an advanced practice nurse, understanding these fundamental pharmacotherapeutic concepts is important to ensure that the prescription drugs you recommend for your patients will be safe and effective to treat and/or manage their symptoms. Additionally, as the advanced practice nurse, it is your responsibility to ensure that when prescribing prescription drugs, you adhere to the ethical and legal principles set forth for prescribing drugs as an added layer of protection and safety for the patients you will treat.

This week, you will analyze factors that may influence pharmacokinetic and pharmacodynamics processes of a patient and assess the details of a personalized plan of care that you develop based on influencing factors and patient history. You will also evaluate and analyze ethical and legal implications and practices related to prescribing drugs, including disclosure and nondisclosure, and analyze the process of writing prescriptions to avoid medication errors.

Learning Objectives

Students will:

  • Analyze factors that influence pharmacokinetic and pharmacodynamic processes in patients
  • Assess patient factors and history to develop personalized plans of care
  • Evaluate ethical and legal implications related to prescribing drugs
  • Analyze ethical and legal practices of prescribing drugs
  • NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics
  • Analyze strategies to address disclosure and nondisclosure
  • Justify advanced practice nurse strategies to guide prescription drug decision-making
  • Analyze the process of writing prescriptions to avoid medication errors

NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics Learning Resources

Required Readings (click to expand/reduce)
Required Media (click to expand/reduce)

Discussion: Pharmacokinetics and Pharmacodynamics

As an advanced practice nurse assisting physicians in the diagnosis and treatment of disorders, it is important to not only understand the impact of disorders on the body, but also the impact of drug treatments on the body. The relationships between drugs and the body can be described by pharmacokinetics and pharmacodynamics.

Pharmacokinetics describes what the body does to the drug through absorption, distribution, metabolism, and excretion, whereas pharmacodynamics describes what the drug does to the body.

Photo Credit: Getty Images/Ingram Publishing

When selecting drugs and determining dosages for patients, it is essential to consider individual patient factors that might impact the patient’s pharmacokinetic and pharmacodynamic processes. These patient factors include genetics, gender, ethnicity, age, behavior (i.e., diet, nutrition, smoking, alcohol, illicit drug abuse), and/or pathophysiological changes due to disease. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.

For this Discussion, you reflect on a case from your past clinical experiences and consider how a patient’s pharmacokinetic and pharmacodynamic processes may alter his or her response to a drug.

To Prepare
  • Review the Resources for this module and consider the principles of pharmacokinetics and pharmacodynamics.
  • Reflect on your experiences, observations, and/or clinical practices from the last 5 years and think about how pharmacokinetic and pharmacodynamic factors altered his or her anticipated response to a drug.
  • Consider factors that might have influenced the patient’s pharmacokinetic and pharmacodynamic processes, such as genetics (including pharmacogenetics), gender, ethnicity, age, behavior, and/or possible pathophysiological changes due to disease. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.
  • Think about a personalized plan of care based on these influencing factors and patient history in your case study.
By Day 3 of Week 1

Post a description of the patient case from your experiences, observations, and/or clinical practice from the last 5 years. Then, describe factors that might have influenced pharmacokinetic and pharmacodynamic processes of the patient you identified. Finally, explain details of the personalized plan of care that you would develop based on influencing factors and patient history in your case. Be specific and provide examples. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.

By Day 6 of Week 1

Read a selection of your colleagues’ responses and respond to at least two of your colleagues on two different days by suggesting additional patient factors that might have interfered with the pharmacokinetic and pharmacodynamic processes of the patients they described. In addition, suggest how the personalized plan of care might change if the age of the patient were different and/or if the patient had a comorbid condition, such as renal failure, heart failure, or liver failure.

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 “Post to Discussion Question” link, and then select “Create Thread” to complete your initial post. Remember, once you click on Submit, you cannot delete or edit your own posts, and you cannot post anonymously. Please check your post carefully before clicking on Submit! NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics

Submission and Grading Information

Grading Criteria

To access your rubric:

Week 1 Discussion Rubric

Post by Day 3 of Week 1 and Respond by Day 6 of Week 1

To Participate in this Discussion:

Week 1 Discussion

Assignment: Ethical and Legal Implications of Prescribing Drugs

What type of drug should you prescribe based on your patient’s diagnosis? How much of the drug should the patient receive? How often should the drug be administered? When should the drug not be prescribed? Are there individual patient factors that could create complications when taking the drug? Should you be prescribing drugs to this patient? How might different state regulations affect the prescribing of this drug to this patient?

These are some of the questions you might consider when selecting a treatment plan for a patient.

Photo Credit: Getty Images/Caiaimage

As an advanced practice nurse prescribing drugs, you are held accountable for people’s lives every day. Patients and their families will often place trust in you because of your position. With this trust comes power and responsibility, as well as an ethical and legal obligation to “do no harm.” It is important that you are aware of current professional, legal, and ethical standards for advanced practice nurses with prescriptive authority. Additionally, it is important to ensure that the treatment plans and administration/prescribing of drugs is in accordance with the regulations of the state in which you practice. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics. Understanding how these regulations may affect the prescribing of certain drugs in different states may have a significant impact on your patient’s treatment plan. In this Assignment, you explore ethical and legal implications of scenarios and consider how to appropriately respond.

To Prepare
  • Review the Resources for this module and consider the legal and ethical implications of prescribing prescription drugs, disclosure, and nondisclosure.
  • Review the scenario assigned by your Instructor for this Assignment.
  • Search specific laws and standards for prescribing prescription drugs and for addressing medication errors for your state or region, and reflect on these as you review the scenario assigned by your Instructor.
  • Consider the ethical and legal implications of the scenario for all stakeholders involved, such as the prescriber, pharmacist, patient, and patient’s family NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.
  • Think about two strategies that you, as an advanced practice nurse, would use to guide your ethically and legally responsible decision-making in this scenario, including whether you would disclose any medication errors.
By Day 7 of Week 1

Write a 2- to 3-page paper that addresses the following:

  • Explain the ethical and legal implications of the scenario you selected on all stakeholders involved, such as the prescriber, pharmacist, patient, and patient’s family.
  • Describe strategies to address disclosure and nondisclosure as identified in the scenario you selected. Be sure to reference laws specific to your state. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.
  • Explain two strategies that you, as an advanced practice nurse, would use to guide your decision making in this scenario, including whether you would disclose your error. Be sure to justify your explanation.
  • Explain the process of writing prescriptions, including strategies to minimize medication errors.

Reminder: The School of Nursing requires that all papers submitted include a title page, introduction, summary, and references. The School of Nursing Writing Template with Instructions provided at the Walden Writing Center offers 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.

Submission and Grading Information

To submit your completed Assignment for review and grading, do the following:

  • Please save your Assignment using the naming convention “WK1Assgn+last name+first initial.(extension)” as the name.
  • Click the Week 1 Assignment Rubric to review the Grading Criteria for the Assignment.
  • Click the Week 1 Assignment link. You will also be able to “View Rubric” for grading criteria from this area.
  • Next, from the Attach File area, click on the Browse My Computer button. Find the document you saved as “WK1Assgn+last name+first initial.(extension)” and click Open.
  • If applicable: From the Plagiarism Tools area, click the checkbox for I agree to submit my paper(s) to the Global Reference Database.
  • Click on the Submit button to complete your submission. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.

Rubric Detail

 

Select Grid View or List View to change the rubric’s layout.

Name: NURS_6521_Week1_Discussion_Rubric

Excellent Good Fair Poor
Main Posting
45 (45%) – 50 (50%)

Answers all parts of the discussion question(s) expectations with reflective critical analysis and synthesis of knowledge gained from the course readings for the module and current credible sources.

Supported by at least three current, credible sources.

Written clearly and concisely with no grammatical or spelling errors and fully adheres to current APA manual writing rules and style.

NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics
40 (40%) – 44 (44%)

Responds to the discussion question(s) and is reflective with critical analysis and synthesis of knowledge gained from the course readings for the module.

At least 75% of post has exceptional depth and breadth.

Supported by at least three credible sources.

Written clearly and concisely with one or no grammatical or spelling errors and fully adheres to current APA manual writing rules and style.
35 (35%) – 39 (39%)

Responds to some of the discussion question(s).

One or two criteria are not addressed or are superficially addressed.

Is somewhat lacking reflection and critical analysis and synthesis.

Somewhat represents knowledge gained from the course readings for the module.

Post is cited with two credible sources.

Written somewhat concisely; may contain more than two spelling or grammatical errors.

Contains some APA formatting errors.
0 (0%) – 34 (34%)

Does not respond to the discussion question(s) adequately.

Lacks depth or superficially addresses criteria.

Lacks reflection and critical analysis and synthesis.

Does not represent knowledge gained from the course readings for the module.

Contains only one or no credible sources.

Not written clearly or concisely.

Contains more than two spelling or grammatical errors.

Does not adhere to current APA manual writing rules and style.
Main Post: Timeliness
10 (10%) – 10 (10%)
Posts main post by day 3
0 (0%) – 0 (0%)
0 (0%) – 0 (0%)
0 (0%) – 0 (0%)
Does not post by day 3
First Response
17 (17%) – 18 (18%)

Response exhibits synthesis, critical thinking, and application to practice settings.

Responds fully to questions posed by faculty.

Provides clear, concise opinions and ideas that are supported by at least two scholarly sources.

Demonstrates synthesis and understanding of learning objectives.

Communication is professional and respectful to colleagues. .

Responses to faculty questions are fully answered, if posed.

Response is effectively written in standard, edited English.
15 (15%) – 16 (16%)

Response exhibits synthesis, critical thinking, and application to practice settings.

Responds fully to questions posed by faculty.

Provides clear, concise opinions and ideas that are supported by at least two scholarly sources.

Demonstrates synthesis and understanding of learning objectives.

Communication is professional and respectful to colleagues. .

Responses to faculty questions are fully answered, if posed.

Response is effectively written in standard, edited English.
13 (13%) – 14 (14%)

Response is on topic and may have some depth.

Responses posted in the discussion may lack effective professional communication.

Responses to faculty questions are somewhat answered, if posed.

Response may lack clear, concise opinions and ideas, and a few or no credible sources are cited.
0 (0%) – 12 (12%)

Response may not be on topic and lacks depth.

Responses posted in the discussion lack effective professional communication.

Responses to faculty questions are missing.

No credible sources are cited.

NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics
Second Response
16 (16%) – 17 (17%)

Response exhibits synthesis, critical thinking, and application to practice settings.

Responds fully to questions posed by faculty.

Provides clear, concise opinions and ideas that are supported by at least two scholarly sources.

Demonstrates synthesis and understanding of learning objectives.

Communication is professional and respectful to colleagues. .

Responses to faculty questions are fully answered, if posed.

Response is effectively written in standard, edited English.
14 (14%) – 15 (15%)

Response exhibits critical thinking and application to practice settings.

Communication is professional and respectful to colleagues.

Responses to faculty questions are answered, if posed.

Provides clear, concise opinions and ideas that are supported by two or more credible sources.

Response is effectively written in standard, edited English.
12 (12%) – 13 (13%)

Response is on topic and may have some depth.

Responses posted in the discussion may lack effective professional communication.

Responses to faculty questions are somewhat answered, if posed. .

Response may lack clear, concise opinions and ideas, and a few or no credible sources are cited.
0 (0%) – 11 (11%)

Response may not be on topic and lacks depth.

Responses posted in the discussion lack effective professional communication.

Responses to faculty questions are missing.

No credible sources are cited.

NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics
Participation
5 (5%) – 5 (5%)
Meets requirements for participation by posting on three different days.
0 (0%) – 0 (0%)
0 (0%) – 0 (0%)
0 (0%) – 0 (0%)
Does not meet requirements for participation by posting on 3 different days
Total Points: 100

Name: NURS_6521_Week1_Discussion_Rubric

Discussion week 1
COLLAPSE

According to Laureate Education, (2019) billions of prescriptions are written annually and it breaks down to five scripts per person per year. Ethical and legal challenges are associated with each prescription written so as for nurse practitioners, we should at very least have a fundamental knowledge base of medications, how they work, the mechanism of action, how long they take to work, how long they last and how to reverse them prior to prescribing them because not every medication works for everyone the same way. Pharmaceutical companies are aware of this and because they are, they market drugs, get feedback and make changes to the same drug and remarket them under a different name which according to Collier, (2014) cost hundreds of thousands of dollars. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.

According to Rosentham and Burchum, (2018) efficacy and potency are measured on a curve to evaluate how they work on a patient, maximum efficacy is the maximum benefit the drug is capable of and potency  is evaluated based on dose for example if a patient has a tolerance for a narcotic medication, choosing the lowest dose of a stronger medication may not be effective, this patient requires either a higher dose or a more potent medication. With pharmacokinetics there is a fine line between what works and what is too much so achieving that balance requires knowledge to prescribe a concentration to achieve the desired effects and minimize harm to the patient (2018).

This brings me to a situation I have encountered many times in the ICU. The area I work serves a large population of homeless and it is surrounded by a low-socioeconomic area where non-compliance and illicit drug use is prevalent. A lot of our patients are found in an unresponsive state and require mechanical ventilation, the standard sedation for this population is propofol and often times patients remain wide awake on the maximum dose of 80mcg/kg/min, the desired effect is not achieved so for the safety of the patient, of course after evaluating kidney and liver function, more potent drugs are added to achieve sedation. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics. Behavior including illicit drug use is why these patients require more sedating drugs due to tolerance so in my facility they will add a fentanyl drip and versed drip and if those are not effective, a Nimbex drip is added to their arsenal just to achieve sedation. Administered for 24 hours as a paralytic and then weaned off to see the benefit of the sedation.

When it comes down to requiring all these medications, other systems are compromised and require additional drips. For example, all of the sedatives cause a decrease in the blood pressure and vasopressors are required to maintain blood pressure and according to Laureate Education, (2019) Dr. Terry Buttaro discusses the importance of having knowledge of drugs when they are prescribed, monitoring the effectiveness, understanding the risks to other organs when selecting certain drugs and achieving the best response should prepare the nurse or practitioner to anticipate risks associated with these high risk medications. As the bedside nurse caring for these types of patients assessing neurological status is not easy but is necessary to ensure the drugs are not causing more harm than good. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.

The plan of care for this patient population is to frequently check neuro status and to wean off the drips as soon as possible because the long-term sequelae associated with them can be detrimental. Once the patient can be extubated, education about substance abuse and recommendations for a rehab program and a case management referral are necessary.

References

Collier R. (2014). The art and science of naming drugs. CMAJ : Canadian Medical Association

journal = journal de l’Association medicale canadienne, 186(14), 1053.

doi:10.1503/cmaj.109-4864 Retrieved from

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4188646/

Laureate Education (Producer). (2019) Introduction to Advanced Pharmacology Program [Video

file]. Baltimore, MD: Author. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.

Laureate Education (Producer). (2019) Pharmacotherapeutic Concepts and Challenges Program

[Video file]. Baltimore, MD: Author.

Rosenthal, L. D., & Burchum, J. R. (2018). Lehnes pharmacotherapeutics for advanced practice

providers. St. Louis, MO: Elsevier.

Main Post

Many individual patient factors can alter the pharmacokinetics and pharmacodynamics of medication administration and require special care and attention to detail to avoid adverse outcomes. It is the responsibility of the prescriber to take all possible variables into consideration when ordering medications, so as to minimize the risk of adverse drug reactions (Rosenthal & Burchum, 2018). A patient will be presented in the following study with special attention paid to their unique modifiers of pharmacokinetics and pharmacodynamics, with a detailed and individualized plan of care presented. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics

Case Study

The patient presented is a 25-year-old African American male who presented to the emergency department after a motorcycle crash and has been diagnosed with numerous rib fractures and contusions but is otherwise unharmed. This patient will require pain medication and anti-inflammatory medication prescriptions, as he will experience significant pain related to the release of histamines, PGE2, and other prostaglandins produced by the actions of cyclooxygenase from muscle breakdown due to his recent trauma (Kumar, Abbas, & Aster, 2018). Although this may seem straightforward, a careful history must be obtained to safely prescribe this patient medications.

Influential Factors on Pharmacologic Processes

This patient has a glucose-6-phosphate dehydrogenase deficiency (G6PD), a noted genetic factor that must be considered, and is far more common in African American males (Huether & McCance, 2017). This disorder can adversely affect the pharmacodynamic properties of various drugs, creating unwanted and even life-threatening side effects. This deficiency causes hemolytic anemia when red blood cells are exposed to oxidative stress, as they lack the protective enzyme G6PD (Kumar et al., 2018) NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics. This can pose a problem, as it is not routinely screened for unless the patient is in the military and being deployed to an area with malaria, as hydroxychloroquine can cause the reaction; or if the patient is HIV positive since dapsone can also cause this and is used for prophylaxis against Pneumocystis jiroveci pneumonia (Aminoff et al., 2018). Fortunately, this patient is an active duty service member and knew about his G6PD deficiency, claiming it was a mild form and he could tolerate short doses of NSAIDs. The patient’s age and relatively good state of health will affect the pharmacokinetic properties of most medications given to him by faster absorption and elimination, related to his healthy renal and hepatic system (Rosenthal & Burchum, 2018) NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.

Detailed Plan of Care

Although this patient does state that his G6PD deficiency is mild, a prescription of NSAIDs would still prove unsafe, due in part to the unpredictable nature of adverse drug reactions, and due in part to the fact that his red blood cells are now already likely receiving oxidative stress due to elevated inflammation and prostaglandins from his recent trauma (Kumar et al., 2018). Opioids are effective for short term pain relief, and are safe in G6PD deficient patients, as long as they are given for short durations to avoid dependence, and intranasal Narcan can be given with instructions for use to prevent overdose (Aminoff et al., 2018). A lidocaine patch is another good choice for topical pain relief and has no dependence potential. Oral acetaminophen is also a safe and effective choice for this patient, but it should be noted that most opioid medications also include acetaminophen in them, and care should be taken not to use both concurrently to avoid liver toxicity (Aminoff et al., 2018). NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.

Summary

Great care must be taken when prescribing medications to patients, even in the relatively young and healthy. A thorough history and physical, as well as a detailed medication reconciliation will prevent many potential errors and must be performed by the prescriber. By taking these steps and considering patient-specific factors, medications can be tailored to the patient’s specific needs and dosed safely.

References

Aminoff, M. J., Basbaum, A. I., Beauduy, C. E., Benowitz, N. L., Biaggioni, I., Bikle, D. D., … Zehnder, J. L. (2018). Basic and clinical pharmacology (14th ed.). : McGraw-Hill Education.

Huether, S. E., & McCance, K. L. (2017). Understanding pathophysiology (6th ed.). St. Louis, MO: Mosby.

Kumar, V., Abbas, A. K., & Aster, J. C. (2018). Robbins basic pathology (10th ed.). Philadelphia, PA: Elsevier.

Rosenthal, L. D., & Burchum, J. R. (2018). Lehne’s pharmacotherapeutics for advanced practice providers. St. Louis, MO: Elsevier. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.

 

6521N Week 1 Discussion

Initial Post

            Pharmacokinetics is the way the body effects a drug, while pharmacodynamics is how a drug effects the body (Arcangelo, Peterson, Wilbur, & Reinhold, 2017).  Being familiar with how drugs are absorbed, processed, and excreted allows practitioners to best approach pharmaceutical treatment.  Desired treatment outcomes and patient compliance, while minimizing side effects and reactions, are the goals of medication therapy.  Considering both pharmacokinetics and pharmacodynamics is critical in determining a patient’s drug regimen. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.

Clinical Practice

          For the last two years I have worked in post anesthesia care (PACU).  Every year my entire unit must complete competency testing for a specific life-threatening drug reaction that is rarely ever seen.  Only 1% of the population has the genetic variation responsible for this drug-induced emergency, but heavily educating staff is still required (Behrooz, 2015).  Over the course of the last two years in PACU, I have had one patient preoperatively diagnosed with this genetic variation, but thankfully I have never witnessed the actual reaction.  As part of best clinical practice at my facility, the deviation in pharmacokinetics and pharmacodynamics of these patients demand close attention to signs and symptoms throughout surgery, but also postoperatively.

          Malignant hyperthermia (MH) is an altered reaction to certain anesthetics that can occur up to 24 hours after exposure.  Specifically, it is a genetic condition where anesthesia induction gases like sevoflurane and isoflurane, as well as the muscle paralytic succinylcholine, are abnormally metabolized (Behrooz, 2015).  These agents trigger the uncontrolled release of calcium, leading to abnormal muscle contraction, damage, and wasting.  Acute kidney failure and a hypermetabolic state ensues.  Without proper treatment, MH is fatal. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.

          “MH is an autosomal dominant condition characterized by hypermetabolism, hypoxia, hypercapnia and hyperthermia resulting from abnormal calcium homeostasis, and is thought to be due to mutations in the ryanodine receptor type 1 gene (RYR1) in 70% of cases” (Behrooz, 2015, p. 473).  This being said, family history is the biggest indicator for MH.  Patients without prior knowledge of family medical history who undergo anesthesia for the first time may not know they have the condition until it occurs. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics. For this reason, dantrolene, which inhibits calcium release and relaxes hyper-contracted skeletal muscles in MH, must be kept in all operating areas and recovery units in case of MH crisis (Behrooz, 2015).

          Testing for MH requires a muscle biopsy that is “exposed to halothane and caffeine”; muscle contracture is a positive MH diagnosis (Behrooz, 2015, p. 473).  Patient’s diagnosed with MH may still be anesthetized or temporarily paralyzed, but it must be done with IV anesthetics and alternative neuromuscular blockers such as Propofol and rocuronium.

Influencing Factor

            Malignant hyperthermia is a dysfunction of cellular processes after exposure to inhaled general anesthetics or IV succinylcholine.  The factor of influence is a genetic mutation of the ryanodine receptor and its effect on calcium channel subunits (Beam, Loudermilk, & Kisor, 2017).  With this hereditary malfunction, medication effects are not the usual course.  Cellular error does not allow appropriate calcium channel tasks.  This is known as “channelopathies” and make patients susceptible to MH (Beam et al., 2017, p. 82).  Pharmacodynamics is prevalent.

            Also apparent is the inhibitory mechanism of MH treatment.  Dantrolene is used to inhibit calcium ion release from the sarcoplasmic reticulum by directly binding to RYR1 (Beam et al., 2017).  According to Rosenthal & Burchum, “inhibition occurs when an antagonist drug blocks access of an agonist drug to its receptor” (2018, p. 38).  Monitoring patients for recurrent MH after dantrolene administration is required for up to 48 hours after the reaction (Beam et al., 2017). NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.

Personalized Plan of Care

          Personalizing a plan of care is centered around obtaining accurate family and medical history of a patient.  Asking if they have any blood-relatives who have had emergencies from anesthesia or asking if the patient has had any previous problems with anesthesia themselves are insights into assessing risk for MH.  Patients with certain genetic muscular disorders also pose a higher susceptibility for MH (Beam et al., 2017).  Unfortunately, testing patients for MH is not standard surgery protocol.  Performing a muscle biopsy is invasive and must be indicated based on high suspicion of MH or family history (Behrooz, 2015).  Another issue is that genetic testing for MH is not often available at most facilities making is more difficult to diagnose (Behrooz, 2015).

          If a patient is diagnosed with MH, plan of care is preventatively provided per the anesthesia team.  In the non-surgical setting, avoiding succinylcholine for rapid sequence intubation is necessary.  While MH is most likely to occur within 35 minutes of receiving a depolarizing neuromuscular blockade and within 140 minutes of halogenated anesthetics, MH can occur at any point during and after the triggering agent is administered (Beggs, McCann, & Powers, 2012).  This means anesthesia providers may no longer be actively caring for the patient and it may be up to the acute care practitioner to treat.  Understanding influencing factors like genetics play an important role in medical management. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.

References

Arcangelo, V. P., Peterson, A. M., Wilbur, V., & Reinhold, J. A. (Eds.). (2017). Pharmacotherapeutics for advanced practice: A practical approach (4th ed.). Philadelphia, PA: Wolters Kluwer.

Beam, T. A., Loudermilk, E. F., & Kisor, D. F. (2017). Pharmacogenetics and pathophysiology of CACNA1S mutations in malignant hyperthermia. Physiological Genomics, 49(2), 81-87. http://dx.doi.org/10.1152/physiolgenomics.00126.2016

Beggs, A. E., McCann, J. Q., & Powers, J. M. (2012). Delayed-onset malignant hyperthermia in association with rocuronium use. American Journal of Health-System Pharmacy, 69(13), 1128-1134. http://dx.doi.org/10.2146/ajhp110306

Behrooz, A. (2015). Pharmacogenetics and anesthetic drugs: Implications for perioperative practice. Annals of Medicine and Surgery, 4(4), 470-474. http://dx.doi.org/10.1016/j.amsu.2015.11.001

Rosenthal, L. D., & Burchum, J. R. (2018). Lehne’s pharmacotherapeutics for advanced practice providers. St. Louis, MO: Elsevier. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.

 

Prescribing medications can be a challenge for the health care provider due to many factors that can hinder the intended use of a drug. Most pharmaceutical drugs are tested on people that are younger and healthier. Working with the geriatric population, many of the drugs have an adverse effect on the patient. For example, the geriatric population may take multiple medicines that is due to a chronic health condition. One pill can have many effects on the body a process called pharmacokinetics. There are four basic pharmacokinetic processes: absorption, distribution, metabolism, and excretion (Rosenthal & Burchum, 2018). Those individuals with advanced age are at a higher risk for toxicity due to the natural process of aging. They are more likely to have fewer nephrons that aid in filtering the toxins out of the body. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics. Pharmacodynamics effects are not only therapeutic but also toxic and adverse effects(Rosenthal & Burchum, 2018).

On a cardiac ICU unit, there are many challenges with hypertensive medications and antiarrhythmics. Most of the patient have a decrease in arterial compliance, which affects the baroreceptors in the carotid and causes orthostatic hypotension (Midlöv, 2013). At times the low blood pressure causes them to be increasingly anxious and sometimes confused.

A 65-year-old African Male with uncontrolled hypertension assessing the patient and getting a detailed history will help identify many factors that will affect the patient medication regimen. it is the duty of the nurse practitioner to provide assessment prior to drug administration (Ladd & Hoyt, 2016).  Collecting other pertinent data labs, echo, and imaging will guide what is clinically safe for the patient. The labs will help identify glomerular filtration Rate and if the patient will be able to clear the medication to prescribe. The echocardiogram will give an estimate on how well the heart is function and if it is enlarged. Focusing on the underlying cause with diet and exercise modifications followed by hypertensive medications. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics.

References

Ladd, E., & Hoyt, A. (2016). Shedding light on nurse practitioner prescribing. The Journal for Nurse Practitioners, 12(3), 166–173. doi:10.1016/j.nurpra.2015.09.17

Midlöv P. (2013). Pharmacokinetics and pharmacodynamics in the elderly. OA Elderly Medicine 2013 Aug 01;1(1):1.

Rosenthal, L. D., & Burchum, J. R. (2018). Lehne’s pharmacotherapeutics for advanced practice providers. St. Louis, MO: Elsevier. NURS 6521 Discussion: Pharmacokinetics and Pharmacodynamics