Pharmacokinetics and Pharmacodynamics
As an advanced practice nurse, it is vital to develop a strong foundation of knowledge in the concepts of pharmacology. Pharmacokinetics and psychodynamics are understanding the basis of the reciprocal relationship between medications and the human body (Laureate Education, 2019; Rosenthal & Burchum, 2018). Factors that influence prescriptive decisions, such as age, genetics, and medical history are the basis of an individualized treatment while considering the advanced practice nurse comfort level in prescribing. Sabatino et al., (2017) explains that “formative education” enhances preparedness (p. 254). Therefore, in this discussion, I will present a patient scenario based on experience in the clinical setting describing factors that influence decision-making. Lastly, I will describe the details and provide examples of the personalized plan of care for the identified patient in the scenario considering influencing factors.
Patient Scenario
A 73-year-old Caucasian male presents to the community mental health outpatient clinic for medication follow up related to Post-Traumatic Stress Disorder (PTSD). The patient is a retired Vietnam Marine Combat Veteran. The patient served a two-year tour in Vietnam in the infantry division. The patient has a well-documented diagnosis of PTSD. The patient completed the PTSD therapy program. The patient’s problem list includes PTSD, insomnia, depression, hypertension, migraine headaches, and hyperlipidemia. The current medication list is as follows: Nortriptyline 10mg at bedtime, Propranolol 120mg daily, Amlodipine 5mg daily, and Atorvastatin 20mg with the evening meal. The medical and mental health conditions are well-controlled with medications. The patient is compliant with his primary care medical treatment. The patient is a non-smoker, with no history of alcohol or illicit drug abuse. The chart review reveals no known allergies. The patient’s last EKG was within normal limits. The patient’s mini-mental exam was within normal limits. In the recent past, the patient reports an active lifestyle, including mountain climbing, target shooting, and hunting. However, the patient reports since his wife became chronically ill, he is not able to do the things he once enjoyed due to financial barriers and time constraints. The patient also reports he is the primary caretaker for his wife.
Factors Influencing Fundamental Concepts
Pharmacokinetics and psychodynamics influence prescribing. In the patient scenario, age is an important factor. Absorption and distribution of medications are influenced by blood flow. Therefore, it is vital to obtain a thorough health history in the aging adult to ensure circulatory problems do not affect medication distribution or absorption. In the older adult, Drug metabolism decreases with age. According to Rosenthal and Burchum (2018), the older adult patient may need lower doses to prevent toxicity. Drug excretion also declines with age. Kidney function declines due to certain factors, such as (1) smaller kidneys, (2) lower nephrons and (3) changes in vessels influencing kidney blood flow (Rosenthal & Burchum, 2018, p. 24).
Personalized Plan of Care
According to Rosenthal and Burchum (2018), there are multiple factors to consider in developing a personalized plan of care for a patient, such as: (1) cost, (2) treatment guidelines, (3) pharmacy formulary, (4) interactions, (5) side effects, (6) allergies to medications, (7) liver and kidney function, (8) age and (9) drug monitoring (p. 5-6). In this scenario, the first thing to consider is medication selection is cost and availability. The patient is retired, on a fixed income, and has financial constraints due to medical bills that occurred from his wife’s illness. A low-cost medication, readily available medication is key for compliance and wellness. Rosenthal and Burchum (2018) explain that even if a patient wants to be compliant, cost and availability may prohibit the patient from filling the prescription. Secondly, medication interactions and side effects are vital to consider in this 73-year-old patient. In the older patient population, polypharmacy increases the risk of side effects ( Lai & Fok, 2017). Medication monitoring should be included in the plan of care. The patient is currently taking Nortriptyline daily. According to Stahl (2017), EKG and lab monitoring is essential in the older population. In fact, a baseline EKG is recommended upon initial prescribing, and monitor plasma levels in the elderly (Stahl, 2017). Finally, an important factor to consider is assessing memory and forgetfulness. Rosenthal and Burchum (2018) explain a common reason for non-compliance with medication is forgetfulness or memory impairment. In this scenario, assessing memory and forgetfulness should take place at each visit considering the patient’s age factor.
Factors Influencing Fundamental Concepts
As you mentioned, pharmacokinetic and pharmacodynamic factors influence prescribing. In the patient scenario, age is an important factor. Absorption and distribution of medications are influenced by blood flow. Therefore, it is vital to obtain a thorough health history in the aging adult to ensure circulatory problems do not affect medication distribution or absorption.
In the older adult, Drug metabolism decreases with age. According to Rosenthal and Burchum (2018), the older adult patient may need lower doses to prevent toxicity. Drug excretion also declines with age. Kidney function declines due to certain factors, such as (1) smaller kidneys, (2) lower nephrons and (3) changes in vessels influencing kidney blood flow (Rosenthal & Burchum, 2018, p. 24).
Personalized Plan of Care
According to Rosenthal and Burchum (2018), there are multiple factors to consider in developing a personalized plan of care for a patient, such as:
Cost
Treatment guidelines
Pharmacy formulary
Interactions
Side effects
Allergies to medications
Liver and kidney function
Age
Drug monitoring
In this scenario, the first thing to consider is medication selection is cost and availability. The patient is retired, on a fixed income, and has financial constraints due to medical bills that occurred from his wife’s illness. A low-cost medication, readily available medication is key for compliance and wellness. Rosenthal and Burchum (2018) explain that even if a patient wants to be compliant, cost and availability may prohibit the patient from filling the prescription.
Secondly, medication interactions and side effects are vital to consider in this 73-year-old patient. In the older patient population, polypharmacy increases the risk of side effects ( Lai & Fok, 2017). Medication monitoring should be included in the plan of care. The patient is currently taking Nortriptyline daily. According to Stahl (2017), EKG and lab monitoring is essential in the older population. In fact, a baseline EKG is recommended upon initial prescribing, and monitor plasma levels in the elderly (Stahl, 2017). Finally, an important factor to consider is assessing memory and forgetfulness. Rosenthal and Burchum (2018) explain a common reason for non-compliance with medication is forgetfulness or memory impairment. In this scenario, assessing memory and forgetfulness should take place at each visit considering the patient’s age factor.
Thus, there are many factors to consider when developing a personalized plan of care for an older adult patient. Age, cost, availability, interactions, side effects, allergies, liver and kidney function, and memory are all important factors to consider. By taking all of these factors into account, you can develop a plan of care that is safe, effective, and affordable for your patient.
References
Džidić-Krivić, A., Kusturica, J., Sher, E.K., Selak, N., Osmančević, N., Karahmet Farhat, E. and Sher, F., 2023. Effects of intestinal flora on pharmacokinetics and pharmacodynamics of drugs. Drug Metabolism Reviews, 55(1-2), pp.126-139.
Lai, L., & Fok, M. (2017). Drug related problems and deprescribing in older adults. British Columbia Medical Journal, 59(3), 178-184. Retrieved from https://www.bcmj.org/articles/drug-related-problems-and-deprescribing-older-adults
Laureate Education (Producer). (2019). Pharmacotherapeutic concepts and challenges [Video file]. Baltimore, MD: Author.
Holze, F., Becker, A.M., Kolaczynska, K.E., Duthaler, U. and Liechti, M.E., 2023. Pharmacokinetics and pharmacodynamics of oral psilocybin administration in healthy participants. Clinical Pharmacology & Therapeutics, 113(4), pp.822-831.
Rosenthal, L. D., & Burchum, J. R. (2018). Lehne’s pharmacotherapeutics for advanced practice providers. St. Louis, MO: Elsevier.
Stahl, S. (2017). Stahl’s essential psychopharmacology: Prescriber’s guide (6th ed.). New York, NY: Cambridge University Press.
Sabatino, J. A., Pruchnicki, M. C., Sevin, A. M., Barker, E., Green, C. G., & Porter, K. (2017). Improving prescribing practices: A pharmacist‐led educational intervention for nurse practitioner students. Journal of the American Association of Nurse Practitioners, 29(5), 248–254. doi:10.1002/2327-6924.12446
