Pharmacokinetics and Pharmacodynamics: Understanding Drug Actions and Reactions

Case

I need response to the attached paper ( peer response).

Introduction:

The safe and competent practice of prescribing and managing medications requires a sound understanding of drugs and the conditions that they are used to manage (Rosenthal & Burchum, 2021). Pharmacokinetics is the study of drug movement throughout the body, there are four basic pharmacokinetic processes: absorption, distribution, metabolism, and excretion (Rosenthal & Burchum, 2021).

Pharmacodynamics is the study of the biochemical and physiologic effects of drugs on the body and the molecular mechanisms by which those effects are produced (Rosenthal & Burchum, 2021).

Case As an RN working in the rehabilitation center for years, I observed the number of adult patients with multiple co-morbidities. Mr. Gain is a 72-year-old male patient with a history of diabetes, the patient was admitted to the emergency room with an open wound to the right foot. The patient also presented with watery diarrhea, lab test was positive for C-diff.

Patient transferred to rehab unit for short-term rehab, wound care, and to continue oral vancomycin antibiotic treatment for c-diff. The patient was admitted to the rehab center with oral vancomycin 125 milligrams 4 times a day for ten days. After one week patient presented with nausea, vomiting, abdominal discomfort, low blood pressure, lower back pain, lower abdominal pain and appears weak than normal.

Lab results showed increased BUN and creatine levels. Nephrotoxicity remains the most severe vancomycin-associated adverse effect, as reported by many studies, and is associated with increased mortality, hospital stay, and medical expense (Wang et al., 2021).

Factors that Influence Pharmacokinetics and Pharmacodynamics Pharmacokinetic/pharmacodynamic modeling and simulation is an innovative approach that can help inform crucial decisions, such as predicting clinical endpoints of new doses and dosing regimens or optimization of drug regimens (Lam et al., 2020).

Many factors can influence pharmacokinetics and pharmacodynamics. In this case, age is an important factor that influences pharmacokinetics and pharmacodynamics. The behavior of the patient is another factor, the patient not taking enough fluids and there is an increased rate of fluid loss through watery diarrhea.

By understanding what the body does to the drug (pharmacokinetics) and what the drug does to the body (pharmacodynamics), dosing regimens can be tailored to the elderly population to avoid nephrotoxicity, retaining antimicrobial eradication, and suppressing the emergence of resistance (Lam et al., 2020). Pharmacokinetics Usually, vancomycin is given parenterally to treat infections.

Absorption from the GI tract is poor. Oral administration is employed only for infections of the intestine, mainly CDI. (Lam et al., 2020). Vancomycin is well distributed to most body fluids and tissues. Vancomycin is eliminated unchanged by the kidneys. In elderly patients and patients with renal impairment, the dosage must be reduced (Rosenthal & Burchum, 2021).

Pharmacodynamics is the mechanism and effects of medications in the body, what the medications do to the body, and how they do it. Vancomycin inhibits the cell-wall biosynthesis of bacteria. In addition, vancomycin alters bacterial-cell-membrane permeability and RNA synthesis (Rosenthal & Burchum, 2021).

There is no cross-resistance between vancomycin and other antibiotics. Plan of care Renal toxicity is one of the major adverse effects of vancomycin treatment in elderly patients. In this case, BUN and serum creatine levels are increased than normal levels within one week of antibiotic treatment.

The plan of care for this case is to reduce the dose of vancomycin antibiotics, routine check for vancomycin trough levels. Another plan of care is to discontinue the vancomycin antibiotic, treat it with other antibiotics.

Monitor the patient closely. Monitor lab levels for renal function or urinary tract infection. Observe for any watery diarrhea or formed stools. Administer fluids to maintain hydration.

Provide a private room for the patient and facilitate contact precautions. Strictly follow handwashing with soap and water, whoever comes into contact with the patient.

Conclusion To adequately understand drug actions, reactions, and interactions, we must be aware of the processes that drugs undergo and the mechanisms by which drugs exert their effects, this knowledge has important implications for safe prescribing and drug monitoring (Rosenthal & Burchum, 2021).

Awareness about pharmacokinetics and pharmacodynamics of medications assists the healthcare providers to prescribe proper medications.