Drugs and the Body Practice Questions with Feedback (Questions 20-35)

20. The patient has a diagnosis of multiple sclerosis and is taking the drug interferon beta-1a (Rebif). The patient takes this drug by subcutaneous injection three times a week. The dosage is 44 mcg per injection. If the patient takes an injection on Monday, how much of the drug would still be in the patientÕs system when she takes her next injection on Wednesday, assuming the half-life of the drug is 24 hours? . A) 22 mcg ( . B) 16.5 mcg ( . C) 11 mcg ( . D) 5.5 mcg ( Ans: C Feedback: The half-life of a drug is the time it takes for the amount of drug in the body to decrease to 1 half the peak level it previously achieved. On Tuesday, there would be 22 mcg remaining in the body, so option A is incorrect. On Wednesday 11 mcg would remain, so option C is the correct answer. At 12 hours before taking the next dose on Wednesday, there would be 16.5 mcg remaining. If the injection were not taken on Wednesday, 12 hours after the dose was due, there would be 5.5 mcg remaining. 21. The patient is a 6-year-old child who is taking 125 mg of amoxicillin every 6 hours. Assuming that the half-life of Amoxicillin is 3 hours, how much Amoxicillin would be in the childÕs body at the time of the next administration of the drug? . A) 62.5 mg ( . B) 46.875 mg ( . C) 31.25 mg ( . D) 15.625 mg ( Ans: C Feedback: The half-life of a drug is the time it takes for the amount of drug in the body to decrease to 1 half the peak level it previously achieved. Option A would occur at 3 hours after the original dose of amoxicillin. Option B would occur 4 1/2 hours after the original dose. Option C would occur at 6 hours after the original dose. Option D would occur at 7 1/2 hours after the original dose. 22. A drug with a half-life of 4 hours is administered at a dosage of 100 mg. How much of the drug will be in the patientÕs system 8 hours after administration? Test Bank - Focus on Nursing Pharmacology (8th Edition by Karch) 30 . A) 75 mg ( . B) 50 mg ( . C) 37.5 mg ( . D) 25 mg ( Ans: D Feedback: The half-life of a drug is the time it takes for the amount of drug in the body to decrease to 1 half the peak level it previously achieved. Option A would occur 2 hours after administration of the drug. Option B would occur at 4 hours. Option C would occur at 6 hours. Option D would occur at 8 hours after the original administration of the drug. 23. The nurse administers amoxicillin 500 mg. The half-life of this drug is approximately 1 hour. At what point would the drug level in the body be 62.5 mg if the drug was not administered again? . A) 1 hours after the original dose ( . B) 2 hours after the original dose ( . C) 3 hours after the original dose ( . D) 4 hours after the original dose ( Ans: C Feedback: The half-life of a drug is the time it takes for the amount of drug in the body to decrease to one-half of the peak level it previously achieved. At a dose of 500 mg the drug level would be 250 mg in 1 hour, 125 mg in 2 hours, 62.5 mg in 3 hours, and 31.25 mg in 4 hours so the correct answer is 3 hours. 24. The nurse is caring for a patient who is receiving gentamicin, 250 mg and fluconazole (Diflucan), 500 mg at the same time. The nurse knows that if these two drugs competed with each other for protein- binding sites, what would this do? . A) Make the patient gentamicin deficient ( . B) Make the patient fluconazole deficient ( Test Bank - Focus on Nursing Pharmacology (8th Edition by Karch) 31 C) D) Ans: 25. A) B) C) D) Ans: Counteract any positive benefit the drugs would have Alter the effectiveness of both drugs( D Feedback: Some drugs compete with each other for protein-binding sites, altering effectiveness or causing toxicity when the two drugs are given together. Nothing in the scenario would indicate that the patient would be either Gentamicin or Diflucan deficient, nor does it indicate that these drugs cannot be given together because they would counteract each other. The student nurse asks the instructor why a patient with a central nervous system infection is receiving antibiotics that will not cross the blood brain barrier. What is the instructorÕs most correct response? A severe infection alters the blood brain barrier to allow the drug to cross.( A medication that is water soluble is more likely to cross the blood-brain barrier. Antibiotics are the exception to the blood brain barrier and cross easily.( An infection that spreads outside the central nervous system helps drugs cross the barrier. A Feedback: Effective antibiotic treatment can occur only when the infection is severe enough to alter the blood brain barrier and allow antibiotics to cross. Lipidsoluble, not water-soluble, medications cross the blood brain barrier more easily and most antibiotics are lipid soluble, so they are not the exception. No matter where the infection originates, drugs must cross the blood brain barrier to treat central nervous system infections. The patient is taking low dose aspirin daily for his heart. The nurse knows only a portion of the medication taken actually reaches the tissue due to what process? Distribution( First-pass effect( Reduced absorption Gastrointestinal circulation 26. A) B) C) D) Test Bank - Focus on Nursing Pharmacology (8th Edition by Karch) 32 Ans: B Feedback: Drugs that are taken orally are usually absorbed from the small intestine directly into the portal venous system and then delivers these absorbed molecules into the liver, which immediately break the drug into metabolites, some of which are active and cause effects in the body, and some of which are deactivated and can be readily excreted from the body. As a result, a large percentage of the oral dose is destroyed at this point and never reaches the tissues. This process is not caused by distribution, absorption, or gastrointestinal circulation. 27. What needs to happen to the protein drug complex for the drugs to reach the cells where the drug can act? . A) The protein drug complex must break itself into smaller pieces to enter the capillaries. ( . B) The binding site on the protein picks up a chemical to make it soluble in the serum. ( . C) The drug must break away from the protein-binding site and float freely. ( . D) The drug must be dissolved in the plasma so it can enter the capillaries and then the tissues. ( Ans: C Feedback: Most drugs are bound, to some extent, to proteins in the blood to be carried into circulation. The protein drug complex is relatively large and cannot enter into capillaries and then into tissues to react. The drug must be freed from the proteinÕs binding site at the tissues. This occurs without the introduction of another chemical or by dissolving in it plasma. 28. The nurse is reviewing the results of the patientÕs laboratory tests. What must the nurse keep in mind when reviewing these results related to medication administration? . A) The patientÕs emotional response to the disease process ( . B) The timing of the last dose of medication relative to when blood was drawn ( . C) The possibility of a drug laboratory test interaction ( . D) A change in the bodyÕs responses or actions related to the drug ( Ans: C Feedback: Test Bank - Focus on Nursing Pharmacology (8th Edition by Karch) 33 The body works through a series of chemical reactions. Because of this, administration of a particular drug may alter results of tests that are done on various chemical levels or reactions as part of a diagnostic study. This drug laboratory test interaction is caused by the drug being given and not necessarily by a change in the bodyÕs responses or actions. The patientÕs emotional response or timing of the last dose is not important in drug-laboratory interactions. 29. A patient has come to the clinic and been diagnosed with Lyme disease. The physician has ordered oral tetracycline. What is important for the nurse to include in the teaching plan about tetracycline? (Select all that apply.) . A) Do not take the drug with anything high in sodium content to keep from producing a state of hypernatremia in the body. ( . B) Do not take the drug with foods or other drugs that contain calcium. ( . C) Do not take the drug at the same time you take an iron supplement or with foods that are high in iron content. ( . D) Avoid exposure to the sun when taking this drug as it can turn your skin purple. ( . E) Avoid eating bananas at the same time you take this drug as the potassium content of the tetracycline can produce hyperkalemia in the body. ( Ans: B, C Feedback: The antibiotic tetracycline is not absorbed from the gastrointestinal (GI) tract if calcium or calcium products (e.g., milk) are present in the stomach. It cannot be taken with iron products because a chemical reaction occurs preventing absorption. Although tetracycline can increase sun sensitivity, it does not turn the skin purple. Patients who take tetracycline do not need to avoid eating bananas or foods that are high in potassium. 30. A nurse is caring for a patient taking multiple drugs and is concerned about a possible drug drug interaction. What is the nurseÕs first and best means of avoiding this problem? . A) Consult a drug guide. ( . B) Call the pharmacist. ( . C) Contact the provider. ( . D) Ask another nurse. ( Ans: A Feedback: Test Bank - Focus on Nursing Pharmacology (8th Edition by Karch) 34 31. The A)( B)( C) D) E) Ans: nurse promotes optimal drug effectiveness by doing what? (Select all that apply.) Incorporate basic history and physical assessment factors into the plan of care. Evaluate the effectiveness of drugs after they have been administered.( Modify the drug regimen to modify adverse or intolerable effects. Minimize the number of medications administered to patients.( Examine factors known to influence specific drugs if they are to be effective. A, B, C, E Whenever two or more drugs are being given together, first consult a drug guide for a listing of clinically significant drug drug interactions. Sometimes problems can be avoided by staggering the administration of the drugs or adjusting their dosages. Consulting the pharmacist is not wrong, but it would not be the first action to take. The nurse holds responsibility for his or her own practice so asking a health care provider or another nurse is based on the assumption that that professional is knowledgeable about all drug drug interactions, which is likely not the case. Feedback: Incorporate basic history and physical assessment factors into any plan of care so that obvious problems can be identified and handled promptly. If a drug simply does not do what it is expected to do, further examine the factors that are known to influence drug effects. Frequently, the drug regimen can be modified to deal with that influence. Minimizing the number of medications administered is usually not an option because each drug is ordered for a reason of necessity for the patient. 32. The nurse administers a specific medication to an older adult patient every 4 hours. The patient has a history of chronic renal failure. Why would this patient be at risk for toxic drug levels? . A) Cumulative effect ( . B) First-pass effect ( . C) Drug interactions ( . D) Cross-tolerance effect ( Ans: A Feedback: Test Bank - Focus on Nursing Pharmacology (8th Edition by Karch) 35 If a drug is taken in successive doses at intervals that are shorter than recommended, or if the body is unable to eliminate a drug properly, the drug can accumulate in the body, leading to toxic levels and adverse effects. This is a cumulative effect. First-pass effect addresses the reduction of available drug when taken orally due to metabolism in the liver before the drug reaches the bloodstream. Drug interactions occur when taken with other drugs, food, or complementary alternative therapies. Cross- tolerance is resistance to drugs within the same class. 33. The patient, diagnosed with cancer, is receiving morphine sulfate (a potent narcotic pain reliever) to relieve cancer pain. Approximately every 7 days the medication is no longer effective in controlling the patientÕs pain and a larger dose is needed to have the same effect. How might the nurse explain why this is happening? . A) Tolerance ( . B) Cumulation ( . C) Interactions ( . D) Addiction ( Ans: A Feedback: The body may develop a tolerance to some drugs over time. Tolerance may arise because of increased biotransformation of the drug, increased resistance to its effects, or other pharmacokinetic factors. When tolerance occurs, the amount of the drug no longer causes the same reaction. Therefore, increasingly larger doses are needed to achieve a therapeutic effect. Cumulative effect occurs when the drug is not properly eliminated and more of the drug is administered, resulting in toxic levels accumulating. Interactions occur when the drug reacts badly with another substance such as food, another drug, or an alternative or complementary therapy. Addiction is the psychological need for a substance. 34. While administering a medication that the nurse has researched and found to have limited effectiveness, the patient tells the nurse, I have read all about this drug and it is such a wonder drug. IÕm so lucky my doctor prescribed it because I just know it will treat my problem. The nurse suspects this drug will be more effective than usual for this patient because of what effect? . A) Cumulative effect ( . B) First-pass effect ( . C) Placebo effect ( . D) Cross-tolerance effect ( Ans: C Test Bank - Focus on Nursing Pharmacology (8th Edition by Karch) 36 Feedback: A drug is more likely to be effective if the patient thinks it will work than if the patient believes it will not work. This is called the placebo effect. If a drug is taken in successive doses at intervals that are shorter than recommended, or if the body is unable to eliminate a drug properly, the drug can accumulate in the body, leading to toxic levels and adverse effects. This is a cumulative effect. First- pass effect addresses the reduction of available drug when taken orally due to metabolism in the liver before the drug reaches the bloodstream. Crosstolerance is resistance to drugs within the same class. 35. The nurse administers an intravenous medication with a half-life of 24 hours but recognizes what factors in this patient could extend the drugÕs halflife? (Select all that apply.) . A) Gastrointestinal disease ( . B) Kidney disease ( . C) Liver disease ( . D) Cardiovascular disease ( . E) Route of administration ( Ans: B, C, D Feedback: Kidney disease could slow excretion and extend the drugÕs half-life. Liver disease could slow metabolism resulting in an extended half-life. Cardiovascular disease could slow distribution resulting in a longer half-life. Gastrointestinal disease would not impact half-life because the medication was injected directly into the bloodstream. Route of administration would not extend half-life because IV injection eliminates the absorption step in the process.