16.1 Pharmacokinetics & Pharmacodynamics Introduction
Open Resources for Nursing (Open RN)
Learning Objectives
- Discuss the processes of pharmacokinetics
- Use multiple professional resources, including technology, to identify pertinent information related to drugs
- Describe the processes of pharmacodynamics
- Consider pharmacodynamic differences across the life span
- Differentiate among prescription drugs, over-the-counter drugs, herbals, and dietary supplements
Safe medication administration is a vital component of the nursing role. Every day, nurses make critical decisions regarding the safety, appropriateness, and effectiveness of the medications administered to their clients. Examples of decisions that a nurse might make during client care are as follows:
- Is my client’s heart rate within the correct range to receive this beta-blocker medication?
- Does my client have adequate renal function prior to administering this dose of antibiotic?
- Is this pain medication effective in controlling my client’s discomfort?
To make safe decisions regarding medication administration, the nurse must have a strong understanding of pharmacology, the science dealing with actions of drugs on the body. Symptom management and a client’s overall well-being are strongly connected to the appropriate administration of medications prescribed in a client’s treatment plan. Before a student nurse reviews a medication order, checks a medication administration record, or removes a medication from a dispensing machine, it is essential to have a foundational understanding of how medications interact with the human body. This chapter will review basic concepts related to pharmacokinetics and pharmacodynamics.
Client Scenario
Mr. Curtis is a 47-year-old client admitted to the hospital with increased weakness, fatigue, and dehydration. His skin appears dry, and tenting occurs when skin turgor is evaluated. He is currently undergoing chemotherapy treatment for multiple myeloma and has experienced weight loss of ten pounds within the last two weeks. He describes that “nothing tastes good,” and he feels as if there is “metal taste in his mouth.” When he does eat small meals, he reports that he is often nauseous. The client’s serum albumin level is 3.1 g/dL.
Applying the Nursing Process
Assessment: The nurse identifies that the client is experiencing signs of imbalanced nutrition with the signs of increased weakness, fatigue, and signs of dehydration such as skin tenting and dryness. The client has demonstrated a significant weight loss over the past two weeks and reports “nothing tastes good” and “a metal taste in the mouth.” The client also reports nausea after eating. His serum albumin level reflects signs of malnutrition.
Based on the assessment information that has been gathered, the following nursing care plan is created for Mr. Curtis:
Nursing Diagnosis: Imbalanced Nutrition: Less Than Body Requirements r/t insufficient dietary intake as manifested by weight loss of 10 pounds in the last two weeks, skin tenting and dryness, reports of “nothing tastes good,” and serum albumin of 3.1 g/dL.
Overall Goal: The client will demonstrate improvement in nutrition intake.
SMART Expected Outcome: Mr. Curtis will eat 50% of offered meals and demonstrate dietary tolerance within 24 hours.
Planning and Implementing Nursing Interventions:
The nurse will validate the client’s feelings regarding his current symptoms and provide emotional support. The nurse will determine the time of day when the client’s appetite is highest and offer the highest calorie meal at that time. The nurse will offer high-calorie protein shakes to the client at frequent intervals. The nurse will assess the client’s food preferences and ensure that small frequent meals are offered that incorporate those preferences. The nurse will also encourage the use of plastic utensils and encourage the client to eat mints or chew gum to minimize the metallic taste in the mouth.
Sample Documentation:
Mr. Curtis demonstrates signs of Imbalanced Nutrition: Less Than Body Requirements. He reported a significant weight loss of ten pounds over the past two weeks associated with chemotherapy. He reports feeling nauseous following small meals. He also reports “nothing tastes good” and having “a metal taste in the mouth.” He demonstrates signs of weakness, fatigue, and dehydration. Interventions have been implemented to increase the client’s nutritional intake.
Evaluation:
Twenty-four hours later, the nurse evaluates Mr. Curtis and finds he is able to consume 50% of breakfast with his preferred dietary items. Planned interventions will continue and the nurse plan to reevaluate his progress the following day.
