Posted: November 29th, 2022

Pharmacodynam ics and pharmacokinetics

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.
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Pharmacodynam ics and pharmacokinetics
The patient I’m describing in this case is a 70-year-old African-American man who had rheumatoid arthritis. The patient has had arthritis for 20 years and has been on medication to slow the progression of the disease since it was diagnosed. Nonsteroidal anti-inflammatory drugs, hydroxychloroquine for pain, and methotrexate to slow disease progression are among his medications.
There are factors that influence the pharmacokinetics of the drugs he was taking. Many patient-related factors influence bioavailability, absorption, distribution, metabolism, and distribution. These factors include the patient’s age, which is associated with polypharmacy, the patient’s nutritional status, compliance, drug interaction, and the presence of other comorbidities. The action of drugs on the body, as well as their biochemical and physiological effects (i.e., pharmacodynamics), are influenced by factors such as patient age, race, and pre-existing co-morbidities such as renal disease. (2021, Rosenthal)
In this case, personalized care is required to ensure that the patient experiences the least amount of pain, the least amount of debility, and the least amount of disease progression. Nonsteroidal anti-inflammatory drugs are effective for arthritic pain, but they increase the risk of peptic ulcers. If this is the case, hydroxychloroquine can be used instead. Methotrexate is typically cytotoxic, and its effects must be carefully monitored to avoid toxicity (Rosenthal, 2021). It also causes vomiting and hair loss as side effects. If there is significant joint damage causing loss of function, surgical management will be an option.
The patient I’ll be discussing in this case was one I cared for on a cardiac step-down unit. This patient had end-stage renal failure and required dialysis on a daily basis. They had skipped dialysis for the previous three days. Heart failure, high cholesterol, hypertension, and cardiac arrhythmia were among the co-morbidities. The patient presented to our unit with chest pain and shortness of breath and required emergent inpatient dialysis. The patient had severe hypertension. Before arriving at the ER, the patient had not taken any of their prescribed morning medications. The attending physician prescribed an oral hypertensive medication dose for the patient to take at home. The nurse administered. Shortly after, the patient developed severe bradycardia and loss of consciousness, necessitating the administration of atropine IV to increase the heart rate. This patient’s pharmacokinetics and pharmacodynamics are being influenced by a number of factors.
This patient’s renal drug excretion was hampered by their end-stage renal failure and need for dialysis. They were three days behind schedule, and the patient’s blood pressure medication had accumulated and could not be filtered and excreted through the kidneys due to missed dialysis appointments. When renal failure occurs, the duration and intensity of a drug response may increase (Rosenthal &Burchum, 2021). Due to the reduced drug excretion and prolonged half-life, it also dangerously reduced the patient’s heart rate while treating his blood pressure. Cardiac rhythm monitoring has revealed that bradyarrhythmias are the most common clinically significant arrhythmias in hemodialysis patients (Roehm et al, 2020). Treating patients with heart failure, high blood pressure, and end-stage renal disease can be extremely difficult, especially if the patient is not adhering to medication and appointment schedules.
Knowing the patient’s home dose and last dose taken would aid in calculating the medication’s elimination half-life. Given that this is a renal patient, the half-life would be even longer and absorption would be compromised. This suggests that a medication dose may be too high in patients with HF and advanced kidney dysfunction, and that the dose should be reduced or the dosing interval extended (Kida et al, 2015).
In my case study, I discussed this acute care inpatient hospital patient. If this were a patient of mine in a non-acute primary care clinic setting, the management would be slightly different. Patients with end-stage renal disease have a variety of symptoms, and many of them are often intertwined with or exacerbated by underlying comorbidities, making medication selection difficult. Given that patients with renal disease rely heavily on medication strategies to manage their symptoms, medication selection and management necessitate appropriate follow-up and monitoring by all members of the healthcare team (Cho et al, 2020).