Book cover for Pharmacology and the Nursing Process

Pharmacology and the Nursing Process

Linda Lane Lilley, Shelly Rainforth Collins, Julie S. Snyder

ISBN #9780323087896

7th Edition

394 Questions

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2,697 Students Helped

Homework Questions

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Summary
Learning Objectives
Key Concepts
Example Problems
Explanations
Common Mistakes

Summary

This chapter emphasizes the importance of understanding the profiles of major drug classes including alpha blockers, beta blockers, and alkylating agents. It highlights how alpha blockers such as phentolamine and tamsulosin target the vascular and smooth muscle to treat conditions like hypertension and BPH, while beta blockers modulate cardiac function by inhibiting beta-adrenergic receptors. Additionally, alkylating agents like cisplatin, cyclophosphamide, and mechlorethamine are pivotal in cancer treatment through DNA cross-linking. A robust knowledge of pharmacokinetic properties, drug interactions, and contraindications is essential for effective and safe management of these therapeutics.

Learning Objectives

1

Describe the profiles and mechanisms of action for alpha blockers, beta blockers, and alkylating agents.

2

Explain how drug interactions, pharmacokinetic properties, and contraindications affect the clinical use of these drug classes.

3

Analyze the therapeutic applications of alpha blockers (e.g., phentolamine and tamsulosin) in conditions like hypertension and BPH.

4

Interpret the role of beta blockers in modulating cardiac function through inhibition of beta-adrenergic receptors.

5

Evaluate the importance of alkylating agents (e.g., cisplatin, cyclophosphamide, mechlorethamine) in cancer treatment via DNA cross-linking.

Key Concepts

CONCEPT

DEFINITION

Alpha Blockers

Drugs that inhibit alpha-adrenergic receptors in vascular and smooth muscle tissues, leading to vasodilation and muscle relaxation. They are used to manage conditions such as hypertension and benign prostatic hyperplasia (BPH).

Beta Blockers

Medications that block beta-adrenergic receptors, thereby reducing heart rate and cardiac output. They are used to treat various cardiac conditions and manage blood pressure.

Alkylating Agents

A class of chemotherapy drugs that work by adding alkyl groups to DNA, causing cross-linking and ultimately inhibiting the replication of cancer cells.

Pharmacokinetics

The study of how the body absorbs, distributes, metabolizes, and excretes a drug.

Drug Interactions

Alterations in the effects of a drug when it is co-administered with another substance, which can affect safety and efficacy.

Contraindications

Specific situations or conditions in which a drug should not be used because it may be harmful to the patient.

Example Problems

Example 1

A patient is being prepared for a colonoscopy. The nurse expects which laxative to be used as preparation for this procedure? a methylcellulose b docusate sodium c PEG-3350 d glycerin

Example 2

The nurse is administering oral methylcellulose (Citrucel) and keeps in mind that a major potential concern with this drug is a dehydration. b tarry stools. c renal calculi. d esophageal obstruction.

Example 3

A 45 -year-old woman has been diagnosed with irritable bowel syndrome (IBS) and will be taking lubiprostone (Amitiza). The nurse assesses for conditions that may be contraindications to this drug, such as a constipation. b bowel obstruction. c renal calculi. d anemia.

Example 4

When the nurse teaches a patient about taking bisacodyl tablets, which instruction is correct? a "Take this medication on an empty stomach." b "Chew the tablet for quicker onset of action." c "Take this medication with juice or milk." d "Take this medication with an antacid if it upsets your stomach."

Example 5

A patient has been receiving long-term antibiotic therapy as part of treatment for an infected leg wound. He tells the nurse that he has had "spells of diarrhea" for the last week. Which medication is most appropriate for him at this time? a bismuth subsalicylate b $L$ acidophilus c diphenoxylate with atropine d codeine
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Step-by-Step Explanations

QUESTION

How does tamsulosin work in the treatment of benign prostatic hyperplasia (BPH)?

STEP-BY-STEP ANSWER:

Step 1: Identify the Target - Tamsulosin targets alpha-1 adrenergic receptors located in the smooth muscle of the prostate and bladder neck.
Step 2: Mechanism of Action - By blocking these receptors, tamsulosin reduces smooth muscle tone.
Step 3: Physiological Effect - The reduction in muscle tension helps to improve urine flow and reduce BPH symptoms.
Final Answer: Tamsulosin alleviates BPH symptoms by relaxing the smooth muscle in the prostate and bladder neck, improving urine flow.

Alpha Blockers

QUESTION

Describe the process by which beta blockers modulate cardiac function.

STEP-BY-STEP ANSWER:

Step 1: Understand the Receptors - Beta blockers bind to beta-adrenergic receptors located on cardiac tissue.
Step 2: Inhibition Process - This binding prevents adrenergic stimulation by endogenous catecholamines (like epinephrine and norepinephrine).
Step 3: Resulting Effects - The inhibition slows the heart rate and decreases myocardial contractility.
Final Answer: Beta blockers modulate cardiac function by blocking beta-adrenergic receptors, leading to a reduced heart rate and decreased cardiac output.

Beta Blockers

QUESTION

Explain how cisplatin exerts its anti-cancer effects.

STEP-BY-STEP ANSWER:

Step 1: Drug Entry - Cisplatin enters the cancer cell.
Step 2: DNA Interaction - Once inside, it forms covalent bonds with DNA, causing cross-linking.
Step 3: Disruption of DNA Function - The DNA cross-links inhibit replication and transcription processes.
Step 4: Induction of Cell Death - The interference with DNA function leads to cell apoptosis or death.
Final Answer: Cisplatin exerts its anti-cancer effects by entering the cell, cross-linking DNA, and thereby disrupting DNA replication and transcription, leading to cell death.

Alkylating Agents

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Common Mistakes

  • Confusing the mechanisms of action between alpha blockers and beta blockers.
  • Overlooking the critical role of pharmacokinetics in determining drug efficacy and safety.
  • Neglecting potential drug interactions and contraindications when formulating treatment plans.
  • Misinterpreting the cellular mechanism of alkylating agents, such as the process of DNA cross-linking.