Advanced pharmacology
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 p harmacodynamics 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 abo out 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
SAMPLE
Pharmacokinetics and Pharmacodynamics
As a psychiatric and mental health nurse for the past several years, I have been involved in caring and the treatment of patients.  The most prevalent mental and neurological disorders among those aged 60 years or older are risk factors for anxiety, depression, and dementia. Most older adults are reluctant to seek help regarding mental illness, which leads to reasons behind the inadequate recognition and treatment of mental disorders among older adults (Tampi & Tampi,2020). The relationship between body, drug, and disease is impacted by age, gender, ethicality, and some pathophysiological changes that occur due to an illness. The purpose of this discussion is to reflect on a patient’s case from past clinical experiences and consider how a patient’s pharmacokinetic and pharmacodynamic processes may alter his or her response to a drug. Also, to develop a personalized plan of care based on influencing factors and patient history.
The case that I am presenting involves a 65-year-old Caucasian male with recent diagnosis of Neurocognitive disorder. No known allergy. History of hypertension and benign prostate hyperplasia. The patient has a family history of Alzheimer’s from his mother’s side. The patient lives alone with wife of 40 years and has grown children. Patients’ wife reported an increase in anxiety, agitation, and confusion. Prescribed medication includes Seroquel 12.5 mg PO bid, Norvasc 5mg once daily, Flomax 0.4once daily.  Namenda 5 mg PO daily and Remeron 7.5 PO PRN at bedtime. Upon assessment, the patient was very agitated and aggressive at the beginning of the shift, including physical aggression towards staff and other patients. He was redirected to his room and was give his scheduled medication, fluid intake, and some snacks. An hour later, the patient’s response was the same, which pose a severe risk to the milieu as a whole. The patient’s recent Urine analysis was negative for urinary tract infection (UTI). An on-call physician was notified, and the patient was ordered to have Zyprexa Zaydis 5mg PRN every 6hours as needed.   Shortly after administration. The patient became sleepy and was noted to have unsteady gait; he was assisted to room, bed low and lock, and the bed alarm was activated. The patient remained on close Observation.
The neurocognitive disorder is most common in older adults; it affects the cognitive capacity, which causes a problem with intricate attention, learning, memory, perceptual-motor abilities and causes significant changes in behavior (Jenson & Padilla,2017). Pharmacokinetics and pharmacodynamics are the relationships between drugs and the body. Pharmacokinetics describes what the body does to the drug through absorption, distribution, metabolism, and excretion. In contrast, pharmacodynamics describes what the drug does to the body (Rosenthal & Burchum, 2021). Older adults have a slow metabolism. Therefore, a decrease in gastric emptying increases gastric PH, which changes drug absorption in most older adults.
Furthermore, the effects of similar drug concentrations at the site of action in older adults may be greater or smaller than those in younger people.  In older adults with delirium, H2‐receptor antagonists remain on the list of medications to avoid. Besides, nonbenzodiazepine, benzodiazepine receptor agonist hypnotics should be avoided in older adults with delirium (Frick et al.,2019).
The Plan of care for the patient includes ongoing monitoring and reassessment. Initiating the fall protocols by accompanying the patient to the bathroom, and communication of fall status among staff.  Assessment of the patient for sedation and antipsychotic adverse effects. Additionally, initiating a therapeutic environment by providing other non-pharmacological methods to address agitations and lessen the patient’s aggressive behavior for the safety of the patient and others.
 
References
Fick, D. M., Semla, T. P., Steinman, M., Beizer, J., Brandt, N., Dombrowski, R.,
DuBeau, C. E., Pezzullo, L., Epplin, J. J., Flanagan, N., Morden, E., Hanlon, J., Hollmann, P., Laird, R., Linnebur, S., & Sandhu, S. (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. https://doi-org.ezp.waldenulibrary.org/10.1111/jgs.15767
 
Jensen, L., & Padilla, R. (2017). Effectiveness of Environment-Based Interventions
That Address Behavior, Perception, and Falls in People with Alzheimer’s Disease and Related Major Neurocognitive Disorders: A Systematic Review. American Journal of Occupational Therapy, 71(5), 1–10. https://doi-org.ezp.waldenulibrary.org/10.5014/ajot.2017.027409
Nightingale, G., Schwartz, R., Kachur, E., Dixon, B. N., Cote, C., Barlow, A.,
Barlow, B., & Medina, P. (2019). Clinical pharmacology of oncology agents in older adults: A comprehensive review of how chronologic and functional age can influence treatment-related effects. Journal of Geriatric Oncology, 10(1), 4–30. https://doi-org.ezp.waldenulibrary.org/10.1016/j.jgo.2018.06.008
 
Rosenthal, L. D., & Burchum, J. R. (2021). Lehne’s pharmacotherapeutics for
advanced practice nurses and physician assistants (2^nd ed.) St. Louis, MO: Elsevier.
Tampi, R. R., & Tampi, D. J. (2020). The Most Prevalent Psychiatric Disorder in
Older Adults. Psychiatric Times, 37(7), 44–45.