Main Post- Week 1

Pharmacokinetics and Pharmacodynamics

Pharmacological management of pain can be a challenging task (Davison, 2019). Issues surrounding pharmacokinetics and pharmacodynamic processes serve as a contributing factor. Pharmacokinetics is defined as the movement of medication throughout the body (Rosenthal & Burchum, 2021). This specific process involves absorption, distribution, metabolism, and excretion (Rosenthal & Burchum, 2021). Pharmacodynamics refers to the effects of a drug on the body (Rosenthal & Burchum, 2021). Throughout my nursing career, I have encountered instances in which I was unable to medicate a patient for pain effectively. Although the patient was receiving the opioid at the prescribed dose and frequency, certain factors inhibited the desirable outcomes from being achieved.

One night while working on a medical-surgical floor, I recall caring for a patient that had just come from surgery after having an arterial venous fistula revision. A report was received from the post-anesthesia nurse; the patient was then transferred to the dialysis unit to receive hemodialysis. After about four hours, the patient was accepted to the floor. The patient was a 76-year-old African American with a history of chronic renal failure, diabetes, stroke, and hypertension. The patient complained of pain 10/10 per numerical pain scale. Morphine 5mg prn was administered per order. The pain level was reassessed, and the patient verbalized that the medication was ineffective; another dose was given at the appropriate timeframe with the same results. The physician on call was notified, and the patient received a breakthrough dose of Dilaudid 0.5 mg for pain. The patient later became challenging to arouse with unstable vital signs. A dose of Narcan was administered, and the patient returned to baseline. Various factors can account for why this particular patient experienced this problem.

Although pain relief is often the goal, consideration must be taken when prescribing and administering pain medications. For example, in regards to pharmacokinetics, patients with chronic renal failure have a modified ability to excrete drugs. Kidney failure has an impact on pharmacokinetic parameters of a large percentage of all important drugs (Keller & Hann, 2018). The kidneys are responsible for the majority of drug excretion (Rosenthal & Burchum, 2021). Drugs usually are expelled through the kidneys in the form of urine and saliva, bile, sweat, and breast milk (Rosenthal & Burchum, 2021). In the presence of renal failure, there are many alterations. For one the duration and intensity of a drug response may be amplified (Rosenthal & Burchum, 2021). There is an increased risk for adverse reactions after opioid administration in patients diagnosed with chronic renal failure (Davison, 2019). Metabolites from the pain medications can accumulate, and these patients often have a narrow therapeutic index (Davison, 2019). Also, attention to the patient’s age should be given. Older adults have a decreased rate of metabolizing drugs and may require lower doses to prevent drug toxicity (Rosenthal & Burchum, 2021). The administration of Narcan after Morphine and Dilaudid is an accurate display of a pharmacodynamic interaction. Theses drugs interact at the same site causing inhibition (Rosenthal & Burchum, 2021). In other words, the Narcan blocked the access of the Morphine and Dilaudid to its receptors, reversing the symptoms the patient had exhibited, which indicated overdose.

An appropriate plan in the future for this patient would consist of changing the prescribed pain medications, including the dosage. Incorporating nonpharmacologic pain relief measures will also be beneficial and aid in pain relief. Pharmacological therapy in patients with chronic kidney disease with pain requires special consideration when selecting the right drugs with attention to medication efficacy and safety (Davison, 2019).

References

Davison, S. N. (2019). Clinical pharmacology considerations in pain management in patients with advanced kidney failure. Clinical Journal of the American Society of Nephrology, 14(6), 917–931. https://doi.org/10.2215/cjn.05180418

Keller, F., & Hann, A. (2018). Clinical pharmacodynamics. Clinical Journal of the American Society of Nephrology,13(9), 1413–1420. https://doi.org/10.2215/cjn.10960917

Rosenthal, L. D., & Burchum, J. R. (2021). Lehne’s pharmacotherapeutics for advanced practice nurses and physician assistants (2nd ed.).    St. Louis, MO: Elsevier.

Week 1 Response 2

I am sure working on a med-surge floor, you probably saw many patients requiring pain medications, and considering pharmacokinetics and pharmacodynamics is critical. You did a great job explaining the situation and how the reaction was reversed. We had a saying on the floor I used to work on that “pain probably won’t kill you, but pain killers can.”

Pharmacokinetics and Pharmacodynamics

The BEERS criteria should have been utilized for this patient due to age. This provides a guideline for medications that should be dosed appropriately for the elderly. Dilaudid could have been avoided in this case (American Geriatrics Society 2019 Beers Criteria Update Expert Panel, 2019). Smaller doses are required for geriatric patients, especially in this instance, due to kidney function. Class II narcotics are excreted through the kidneys and can intensify expected pharmacodynamics. Narcan was necessary to inhibit the pharmacokinetics of the Dilaudid by blocking receptors (Rosenthal, Burchum, 2021).

Conclusion

Patient education on pain management would be beneficial in this situation. Being pain-free is unrealistic, but the goal of creating patient comfort safely is ideal. Safe administration of narcotics for elderly post-surgical patients, especially those with comorbidities, is priority for the advanced practice clinician.

References

American Geriatrics Society 2019 Beers Criteria Update Expert Panel. (2019). American Geriatrics Society 2019 updated AGS Beers criteria for potentially inappropriate

medication use in older adults. Journal of the American Geriatrics Society, 67(4), 674–694. doi:10.1111/jgs.15767

Rosenthal, L. D., & Burchum, J. R. (2021). Lehne’s pharmacotherapeutics for advanced practice

nurses and physician assistants (2nd ed.) St. Louis, MO: Elsevier.

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.

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. 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.

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 Post- Pharmacokinetics and Pharmacodynamics

 

One specific case that I remember when I was a floor nurse on a Med-Surg unit was a young lady that came thru the ER with an infected diabetic wound. This patient was non-compliant with following her diabetic regimen such as diet and medications. This patient also had mild renal issues as well. Down in the ER the patient was given a round of Vancomycin as soon as she arrived at the ER. Now at the hospital where I was working at the time, we had a medication scan system in place to help prevent and reduce medication errors. However, this medication scan system was not in place down in our ER at the time.

A lot of the times, nurses would receive the verbal orders from the ER physician then directly put them into the ER pharmacy, administered the medication and then chart it later. This patient came in right before the change of shift, received the Vancomycin and completed the infusion from the first nurse and was handed off to the next nurse on the next shift. The first nurse did not chart that she had administered the Vancomycin, nor did she pass this information in report to the second nurse. The order for the medication was still on the MAR and looked like it had not been given, so of course the second nurse administered a second dose of the Vancomycin. With that being done, this placed the patient into renal failure.

Factors that influenced the patient’s pharmacokinetics are that she already before receiving the double dose of Vancomycin had some mild renal issues which alters her kidney metabolism. Receiving the one dose was already risky due to her impaired renal function. Orders for a vanco peak and trough were place in the patient’s chart to check her vanco levels before the next round of Vancomycin was due to be given, which was in the next 24hours.

 

Personalize Plan of Care

Personalized plan of care for this patient, I would first immediately discontinue the antibiotics and start hemodialysis on the patient the try to preserve what renal function that they have left. I also would order labs daily to continuously monitor the patient’s creatinine levels, to see if they have improved or worsened. Once the patient creatinine levels are improved, I would start this patient on oral antibiotics and continue to closely monitor her renal functions and her glucose levels. Continue to educate the patients on the importance of modification of her diet and compliance with her hyperglycemic medications.

 

References

Web MD, LLC. (n.d.). Drug and Diesease. Retrieved from Medscape: https://reference.medscape.com/drug/firvanq-vancocin-vancomycin-342573