Unit 7 (PHARMACOLOGY) Questions-Adams Chapter 5

Graded dose-response curves are most useful for determining 1. response intensity within an individual. 2. response intensity within a large group of people with different characteristics. 3. response intensity within a large group of people with similar characteristics. 4. response intensity within a small group of people with similar characteristics.

Correct Answer: 1 Rationale 1: Graded dose-response curves are used to determine response intensity within an individual.

Pharmacogenetics is a relatively new area within pharmacology. Which statement best describes the potential of this new area? 1. To customize drugs and prevent idiosyncratic responses 2. To reduce the overall number of drugs and their associated adverse effects 3. To reduce medication errors and provide optimal drug choices 4. To provide cost-effective pharmacotherapy and higher drug efficacy

Correct Answer: 1 Rationale 1: Pharmacogenetics explores the role of heredity in drug response. It might be useful to customize drugs based on genetic makeup and reduce idiosyncratic responses. Currently, increased cost is a deterrent. Reducing the number of drugs might occur, but is not the best descriptive statement.

The median effective dose is best described as 1. the amount of a drug that produces an effect without the presence of adverse effects. 2. the amount of a drug that is metabolized within 24 hours. 3. the amount of a drug that causes an effect in half the population. 4. the amount of a drug that causes an effect in more than half of the population.

Correct Answer: 1 Rationale 1: The median effective dose is the amount of a drug that produces an effect without the presence of adverse effects.

The student nurse asks the nursing instructor why drug plateaus occur with medications. What is (are) the best response(s) by the nursing instructor? Note: Credit will be given only if all correct choices and no incorrect choices are selected. Standard Text: Select all that apply. 1. It could be that all of the receptors for the drug are occupied. 2. It may mean that the drug has brought 100% relief to the patient. 3. It means that the patient has developed resistance and needs another drug. 4. It probably means that the drug is losing efficacy. 5. It means that the patient needs a higher dose of the drug.

Correct Answer: 1,2 Rationale 1: Drug plateaus occur with medications because all the receptors for the drug are occupied; the drug has brought 100% relief to the patient. A drug plateau is not related to efficacy of the drug. When a drug has reached its plateau, giving additional amounts will not result in an increased therapeutic effect.

The nurse explains to a student nurse that the median lethal dose of drugs is often determined in laboratory preclinical trials because Note: Credit will be given only if all correct choices and no incorrect choices are selected. Standard Text: Select all that apply. 1. it would be unethical to determine these values in human subjects. 2. the safety of the medication must be determined prior to clinical trials. 3. it is difficult to obtain sufficient participants for clinical trials. 4. clinical trials determine only the effective dose of a drug. 5. it is too costly to conduct the studies during clinical trials.

Correct Answer: 1,2 Rationale 1: Laboratory animals are used in clinical trials to determine the LD50, or the dose that kills 50% of the subjects. It would be unethical to kill human subjects. Rationale 2: Before a drug is released for trials in human subjects, its safety must be determined. Rationale 3: It can be challenging to obtain sufficient subjects at times, but this is not the reason for doing lethal studies during preclinical trials. Rationale 4: Clinical trials determine not only the effectiveness of a drug, but also its adverse and toxic effects. Rationale 5: The cost of the trials is the reason they are conducted with animal subjects.

The nurse is participating in the clinical trial of a new medication for the treatment of hypertension. To assess the effectiveness of the medication, which interventions would the nurse perform to help determine whether the average dose is effective for the patient? Note: Credit will be given only if all correct choices and no incorrect choices are selected. Standard Text: Select all that apply. 1. Monitoring blood pressure 2. Monitoring heart rate 3. Interpreting laboratory values 4. Monitoring diet 5. Monitoring sleep habits

Correct Answer: 1,2,3 Rationale 1: By monitoring the patients vital signs, the nurse helps to determine whether the average dose is effective for the patient. Rationale 2: By monitoring the patients vital signs, the nurse helps to determine whether the average dose is effective for the patient. Rationale 3: By interpreting any associated laboratory data, the nurse helps to determine whether the average dose is effective for the patient. Rationale 4: Monitoring the patients diet will not help determine if the average dose of a medication is effective for the patient. Rationale 5: Monitoring the patients sleep habits will not help determine if the average dose of a medication is effective for the patient.

The nurse is reviewing the medication administration record for a group of patients and recognizes that which agents have nonspecific cellular responses? Note: Credit will be given only if all correct choices and no incorrect choices are selected. Standard Text: Select all that apply. 1. Ethyl alcohol 2. General anesthetics 3. Osmotic diuretics 4. Calcium channel blockers 5. Alpha-adrenergic antihypertensives

Correct Answer: 1,2,3 Rationale 1: Ethyl alcohol is an example of an agent that acts by nonspecific mechanisms, independently of cellular receptors. Rationale 2: General anesthetics are an example of agents that act by nonspecific mechanisms, independently of cellular receptors. Rationale 3: Osmotic diuretics are an example of agents that act by nonspecific mechanisms, independently of cellular receptors. Rationale 4: Calcium channel blockers have a specific mechanism of action. Rationale 5: Alpha-adrenergic antihypertensives have a specific mechanism of action.

The patient has had hypertension for many years. The physician orders an antihypertensive drug that has just come on the market. The nurse teaches the patient that this drug works more effectively than his prior drug, and has fewer side effects. The patient asks how this can be. What is the best response by the nurse? Note: Credit will be given only if all correct choices and no incorrect choices are selected. Standard Text: Select all that apply. 1. Newer drugs are altered to affect your cells receptors in a different way. 2. Receptors tend to burn-out, so newer drugs are required. 3. Research into receptors helps fine-tune drugs to be more effective. 4. Changing the response of the drug to protein receptor-complexes produces fewer side effects. 5. It is a process of trial and error with receptors until the new drug proves effective.

Correct Answer: 1,3 Rationale 1: Receptor research results in the development of new medications that activate very specific receptors to produce a greater therapeutic response as well as fewer side effects. Research into receptors has resulted in the fine-tuning of medications that are more effective with fewer side effects. Research is not a process of trial and error with receptors. Receptors do not burn-out. There is no such thing as a protein receptor-complex.

The nurse administers narcotics to surgical patients. Which statement represents the nurses best understanding as it relates to the potency of different narcotics? 1. Codeine is less potent than morphine; it will not produce an allergic reaction. 2. Morphine is more potent than codeine; a lesser dose will be required. 3. Morphine is more potent than codeine; it will produce more adverse effects. 4. Codeine is less potent than morphine; it will not relieve pain as well.

Correct Answer: 2 Rationale 1: A drug that is more potent will produce a therapeutic effect at a lower dose. Potency does not mean the drug will produce more adverse effects. Less potent narcotics can be very effective with pain relief. The potency of a drug is not related to its ability to cause an allergic reaction.

The nurse is conducting medication education about the difference between potency and efficacy to a group of patients. The nurse correctly determines that learning has occurred when the patients makes which response? 1. The best drug for us is the one with the highest potency. 2. The best drug for us is the one with the greatest efficacy. 3. Drugs with the greatest efficacy will produce the least side effects. 4. Low potency drugs have efficacy and do not produce side effects.

Correct Answer: 2 Rationale 1: Efficacy means the magnitude of maximal response that can be produced from a particular drug. Potency refers to the dose of the drug; high-potency drugs do not necessarily provide the best response in the patient. Efficacious drugs and low-potency drugs do produce side effects.

The patient and his wife receive the same medication for hypertension. The patients wife asks the nurse why she is receiving a higher amount of the medication. What is the best response by the nurse? 1. Females have a higher metabolism, so you need more medication. 2. Everyone is unique and responds differently to medications. 3. Your hormones are different from your husbands, so you need more medication. 4. You have a greater percentage of body fat, so more medication is needed.

Correct Answer: 2 Rationale 1: Many variables will influence how patients will respond to medications; each patient must be individually evaluated for response to medications. The percentage of body fat, hormones, and the patients rate of metabolism are only a few of the variables involved in the patients response to medications. Females do not necessarily have higher metabolic rates than men.

Which statement explains the usefulness of the median toxicity dose best? 1. Is useful because drug amounts that are lower than the TD50 will not produce the desired effect. 2. Is useful for determining the efficacy and potency of a drug. 3. Is useful because it is not ethical to determine the LD50 in humans. 4. Is useful because drug amounts that exceed the TD50 will be lethal to half the population.

Correct Answer: 2 Rationale 1: Since the LD50 is not ethical to determine in humans, the TD50 is used. The LD50 is used to determine adverse effects in humans, not efficacy or potency.

A patient looks up the drug he is taking in a drug guide. The patient asks the nurse why the physician prescribed a medication that has a lethal dose measure. What is the best response by the nurse? 1. It just refers to what is done in research; it is not used by doctors prescribing drugs. 2. It is a value determined during research, which helps to determine the safe dose to give. 3. All that means is that the drug could be lethal, but I will watch you for side effects. 4. Dont worry about that, Ill have your doctor explain it to you.

Correct Answer: 2 Rationale 1: The difference between a median effective dose and a median lethal dose is a measure of a drugs safety margin, which helps determine the safest dose to give. The lethal dose measure is used by doctors prescribing drugs. Telling a patient not to worry is non-therapeutic; this is a condescending response. Telling a patient that the drug could be lethal, but he will be observed for side effects, will frighten him and most likely result in refusal of the medication.

A patient with hypertension is taking a potent antihypertensive without results. The patient is concerned when the health care provider orders a new drug. The nurse explains, Note: Credit will be given only if all correct choices and no incorrect choices are selected. Standard Text: Select all that apply. 1. The drug you took is very potent, and a higher dose is needed. 2. The new drug has greater efficacy, so it will help reduce your blood pressure. 3. The prescriber must have made an error in the orders. 4. Efficacy in treating your hypertension is more important than potency. 5. You are correct. I think the prescriber meant to order both drugs.

Correct Answer: 2,4 Rationale 1: A higher dose of a potent drug may cause more serious adverse effects without greater efficacy. Rationale 2: Efficacy is more important than potency in providing blood pressure control. Rationale 3: This is not an appropriate response by the nurse. Rationale 4: Efficacy is more important than potency in pharmacologic treatment. Rationale 5: This is not an appropriate response, and the nurse cannot assume the order was supposed to be for two drugs.

From a transcription error a patient received an overdose of a prescribed medication. If the therapeutic index of the medication is 10 and the median effective dose is 2, what would the nurse calculate as the median lethal dose for the medication?

Correct Answer: 20 Rationale : 10 = x/2; solving for x, the median lethal dose would be 20.

If a clinician wanted to prevent the effects elicited from a previously administered medication, which type would be of the most use? 1. An agonist 2. A partial agonist 3. An antagonist 4. A partial antagonist

Correct Answer: 3 Rationale 1: An antagonist occupies receptor sites, preventing them from being activated by the medication.

Drug X has a median lethal dose of 30 mg and a median effective dose of 10. Drug Y has a therapeutic index of 4, while drug Z has a therapeutic index of 3. Which statement is accurate based on this information? 1. Drugs X and Y are safer than drug Z. 2. The therapeutic index of drug X is 20. 3. Drug Y is the safest of the three. 4. Drug Z is the safest of the three.

Correct Answer: 3 Rationale 1: Drug Y is the safest

At a dose of 10 mg, drug X lowers total cholesterol by 50 mg/dL, while a maximum drop in cholesterol of 65mg/dL is achieved at 40 mg. At a dose of 5 mg, drug Y lowers cholesterol by 50 mg/dL, while a maximum drop in cholesterol of 55 mg/dL is achieved at 10 mg. What can be concluded about the efficacy and potency of these two drugs? 1. Drug X is more potent, and drug Y has a higher efficacy. 2. Drug X is more potent, and has higher efficacy. 3. Drug Y is more potent, and has higher efficacy. 4. Drug Y is more potent, and drug X has a higher efficacy.

Correct Answer: 4 Rationale 1: Drug Y causes a greater drop in cholesterol at lower doses (higher potency), whereas drug X causes the highest drop in total cholesterol (efficacy).

Prior to administering medications, the student nurse reviews the therapeutic index. Which statement best describes the students understanding of therapeutic index? 1. The student is able to determine if the physician prescribed the best drug for the patient. 2. The student is able to determine if the patients are receiving safe doses of the medications. 3. The student is able to identify interactions among the drugs each patient is receiving. 4. The student is able to identify the patients who will need to have serum blood levels monitored.

Correct Answer: 4 Rationale 1: Drugs with a narrow therapeutic index have a low safety margin and the concentration of the drug should be monitored by regular serum tests. The therapeutic index will give some information about safe doses, but this is not the most complete response. The therapeutic index will not help to determine if the physician prescribed the best drug for the patient. The therapeutic index will not help to identify interactions among the drugs the patients receive.

The nurse plans to teach a group of patients about how their medications work in their bodies. If education has been successful, what will be the best understanding of the patients? 1. Medications change the function of the cells in the body. 2. Medications help the body produce new enzymes. 3. Medications change how body tissues function. 4. Medications work by enhancing or blocking normal body functioning.

Correct Answer: 4 Rationale 1: Medications work by enhancing or blocking normal body functioning. Medications cannot help the body produce new enzymes, or change the function of the cells or tissues of the body.

The home health nurse notes that the elderly patient doubled up on his pain medication, even though the prescribed dose was at a therapeutic level. The patient says, If one pill is good, two pills are better. Which statement best describes the result of the patients action? 1. The patient develops tolerance and does not experience any difference. 2. The patient experiences more pain relief from the additional dose. 3. The patient develops tolerance and will need increased doses of the drug. 4. The patient exhibits side effects from the additional dose.

Correct Answer: 4 Rationale 1: Once the plateau of a drug has been reached, increasing the dose may produce adverse effects. Once the plateau of a drug has been reached, increased doses will not provide added therapeutic benefit, such as more pain relief. Tolerance may occur, but is not the primary issue here.

The patient was receiving haloperidol (Haldol), a dopamine antagonist. The psychiatrist changed the order to aripiprazole (Abilify), a partial dopamine antagonist. Which statement best describes the effect of the change of medication on the patient? 1. The patient is more compliant in taking his medication. 2. The patient experiences greater efficacy. 3. The patient experiences a greater reduction in symptoms. 4. The patient experiences fewer side effects.

Correct Answer: 4 Rationale 1: Partial blocking of dopamine results in fewer side effects than complete blocking of dopamine. The patient will not necessarily experience greater efficacy or be more compliant in taking the medicine. Experiencing a greater reduction in symptoms is the same as greater efficacy.

The student nurse has been reading about the Human Genome Project and asks the nursing instructor how this will impact future pharmacological therapies. What is the best response by the instructor? 1. We will be able to alter genes so we will not need drugs. 2. We will be able to standardize drug doses to make prescribing easier. 3. It will help prevent disease through gene manipulation, but will not impact drugs. 4. It will help to individualize drug therapy for people in a more effective way.

Correct Answer: 4 Rationale 1: The goal of pharmacogenetics is to help individualize drug therapy for people in a more effective way. Altering genes to prevent illness is a possibility, but we will always need medications. Individuals will still respond differently to medications; not all drugs will have standardized doses. Medications will be very much impacted by this research.

The nursing instructor prepares to teach student nurses about how mean effective doses of medications are related to clinical practice. As a result of the instruction, what is the best understanding of the student nurses? 1. About 50% of patients will experience severe side effects from the drug. 2. Some patients will respond differently depending on their ethnic background. 3. About 50% of patients will not experience any effect from the drug. 4. Some patients will require more or less than the average dose of the drug.

Correct Answer: 4 Rationale 1: The mean effective dose predicts how 50% of the population will respond to the average dose of the drug. Some patients will require more or less of the drug. The mean effective dose is not related to ethnicity. The mean effective dose does not predict how many patients will experience severe side effects from the drug. The mean effective dose does not predict that 50% of patients will not experience any effect of the drug.

The patient receives antibiotics for a serious infection. The patient asks the nurse, Why dont you just give me more of that drug to cure this infection faster? What is the best response by the nurse? 1. I will check with the doctor to see if it is time to increase the medication. 2. You are at a maximum dose; taking more will cause interactions with other medications. 3. You must stay on this drug for 2 more weeks before it can be increased. 4. You are at a maximum dose; taking more will not help.

Correct Answer: 4 Rationale 1: When the plateau of a drug has been reached, administering more of the drug will not produce additional benefit. Once the plateau of a drug has been reached, there is no time frame for an increase in dosage because an increase in dosage will not produce a greater effect. Telling the patient the nurse will check with the physician is inappropriate because the plateau of the drug has been reached; the physician will not change the dosage. An increase in dosage may cause interactions with other medications, but this is not the best answer.

The nurse is preparing to administer a medication to a patient on a medical-surgical unit. The median lethal dose of the drug is 40 mg, and the median effective dose is 10 mg. The nurse calculates the therapeutic index to be _____.

Correct Answer: 4 Rationale : The therapeutic index is calculated by dividing the median lethal dose (LD50) by the median effective dose (ED50).