Pharmacology Questions Part 1 Answers and Rationale

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1. Answer B. Acetaminophen is extensively metabolized by pathways in the liver. Toxic doses of acetaminophen deplete hepatic glutathione, resulting in accumulation of the intermediate agent, quinine, which leads to hepatic necrosis. Prolonged use of acetaminophen may result in an increased risk of renal dysfunction, but a single overdose does not precipitate life-threatening problems in the respiratory system, renal system, or adrenal glands.
2. Answer B. Topical agents produce a localized, rather than systemic effect. When treating atopic dermatitis with a steroidal preparation, the site is vulnerable to invasion by organisms. Viruses, such as herpes simplex or varicella-zoster, present a risk of disseminated infection. Educate the patient using topical corticosteroids to avoid crowds or people known to have infections and to report even minor signs of an infection. Topical corticosteroid usage results in little danger of concurrent infection with these agents.
3. Answer C. Typically, first generation OTC antihistamines have a sedating effect because of passage into the CNS. However, in some individuals, especially infants and children, paradoxical CNS stimulation occurs and is manifested by excitement, euphoria, restlessness, and confusion. For this reason, use of first generation OTC antihistamines has declined, and second generation product usage has increased. Reye’s syndrome is a systemic response to a virus. First generation OTC antihistamines do not exhibit a cholinergic effect. Nausea and diarrhea are uncommon when first generation OTC antihistamines are taken.
4. Answer C. Virus-infected children who are given aspirin to manage pain, fever, and inflammation are at an increased risk of developing Reye’s syndrome. Use of acetaminophen has not been associated with Reye’s syndrome and can be safely given to patients with fever due to viral illnesses. Ibuprofen adverse effects include GI irritation and bleeding, and in toxic doses, both renal and hepatic failure are reported. However, ibuprofen has not been associated with the onset of Reye’s disease. Brompheniramine/psudoephedrine contains a first generation OTC antihistamine and a decongestant. Neither agent has been associated with the development of Reye’s syndrome.
5. Answer B. Some types of contrast media contain iodine as an ingredient. Shellfish also contain significant amounts of iodine. Therefore, a patient who is allergic to iodine will exhibit an allergic response to both iodine containing contrast media and shellfish. These products do not contain iodine.
6. Answer D. The measles portion of the MMR vaccine is grown in chick embryo cells. The current MMR vaccine does not contain a significant amount of egg proteins, and even children with dramatic egg allergies are extremely unlikely to have an anaphylactic reaction. However, patients that do respond to egg contact with anaphylaxis should be in a medically controlled setting where full resuscitation efforts can be administered if anaphylaxis results. The vaccines in options a,b and c do not contain egg protein.
7. Answer A. IgE, the least common serum immunoglobulin (Ig) binds very tightly to receptors on basophils and mast cells and is involved in allergic reactions. Binding of the allergen to the IgE on the cells results in the release of various pharmacological mediators that result in allergic symptoms. IgG is the major Ig (75 percent of serum Ig is IgG). Most versatile Ig because it is capable of carrying out all of the functions of Ig molecules. IgG is the only class of Ig that crosses the placenta. It is an opsonin, a substance that enhances phagocytosis. IgA, the second most common serum Ig is found in secretions (tears, saliva, colostrum, and mucus). It is important in local (mucosal) immunity. IgM, the third most common serum Ig, is the first Ig to be made by the fetus and the first Ig to be made by a virgin B cell when it is stimulated by antigen. IgM antibodies are very efficient in leading to the lysis of microorganisms.
8. Answer A. Aplastic anemia is the result of a hypersensitivity reaction and is often irreversible. It leads to pancytopenia, a severe decrease in all cell types: red blood cells, white blood cells, and platelets. A reduced number of red blood cells causes hemoglobin to drop. A reduced number of white blood cells make the patient susceptible to infection. And, a reduced number of platelets cause the blood not to clot as easily. Treatment for mild cases is supportive. Transfusions may be necessary. Severe cases require a bone marrow transplant. Option 2 is an elevated platelet count. Option 3 is an elevated white count. Option 4 is an elevated granulocyte count. A granulocyte is a type of white blood cell.
9. Answer D. Oral contraceptives have been associated with an increased risk of stroke, myocardial infarction, and deep vein thrombosis. These risks are increased in women who smoke. Increased skin oil and acne are effects of progestin excess. Headache and dizziness are effects of estrogen excess. Early or mid-cycle bleeding are effects of estrogen deficiency.
10. Answer A. All items are adverse reactions of the drug. However, apnea appearing during the first hour of drug infusion occurs in 10-12 percent of neonates with congenital heart defects. Clinicians deciding to utilize alprostadil must be prepared to intubate and mechanically ventilate the infant. Careful monitoring for apnea or respiratory depression is mandatory. In some institutions, elective intubation occurs prior to initiation of the medication.
11. Answer C. Muscle aches, soreness, and weakness may be early signs of myopathy such as rhabdomyolysis associated with the HMG-CoA reducatase class of antilipemic agents. This patient will need an immediate evaluation to rule out myopathy. Additional doses may exacerbate the problem. Exercise will not reverse myopathy and delays diagnosis.
12. Answer A. Levothyroxine, especially in higher doses, can induce hyperthyroid-like symptoms including tachycardia. An agent that increases the basal metabolic rate would not be expected to induce a slow heart rate. Hypotension would be a side effect of bradycardia. Constipation is a symptom of hypothyroid disease.
13. Answer C. Lactic acidosis is the most dangerous adverse effect of metformin administration with death resulting in approximately 50 percent of individuals who develop lactic acidosis while on this drug. Metformin does not induce insulin production; thus, administration does not result in hypoglycemic events. Some nausea, vomiting, and diarrhea may develop but is usually not severe. NVD is not specific for metformin. Metformin does not induce sleepiness.
14. Answer D. Excessive ingestion of TCAs result in life-threatening wide QRS complex tachycardia. TCA overdose can induce seizures, but they are typically not life-threatening. TCAs do not cause an elevation in body temperature. TCAs do not cause metabolic acidosis.
15. Answer A. 0.9 percent sodium chloride is normal saline. This solution has the same osmolarity as blood. Its use prevents red cell lysis. The solutions given in options 2 and 3 are hypotonic solutions and can cause red cell lysis. The solution in option 4 may anticoagulate the patient and result in bleeding.
16. Answer A. Red blood cells contain antigens and antibodies that must be matched between donor and recipient. The blood products in options 2-4 do not contain red cells. Thus, they require no cross-match.
17. Answer B. GVHD occurs when white blood cells in donor blood attack the tissues of an immunocompromised recipient. This process can occur within a month of the transfusion. Options 1 and 4 may be a thought, but the nurse must remember that immunocompromised transfusion recipients are at risk for GVHD.
18. Answer D. The process of apheresis involves removal of whole blood from a donor. Within an instrument that is essentially designed as a centrifuge, the components of whole blood are separated. One of the separated portions is then withdrawn, and the remaining components are retransfused into the donor. Directed donation is collected from a blood donor other than the recipient, but the donor is known to the recipient and is usually a family member or friend. Autologous donation is the collection and reinfusion of the patient’s own blood. Allogenic donation is collected from a blood donor other than the recipient.
19. Answer D. People older than 65 years use 43 percent of donated blood. This number is expected to increase as the population ages.
20. Answer D. Granulocyte (neutrophil) replacement therapy is given until the patient’s blood values are normal and he is able to fight the infection himself. Options 1 and 3 are not therapeutic responses. The treatment in option 2 takes days and is not always able to prevent morbidity and mortality.
21. Answer C. This process is the collection and reinfusion of the patient’s own blood. It is recommended by the American Medical Association’s Council on Scientific Affairs as the safest product since it eliminates recipient incompatibility and infection. The product in option 1 is collected from a blood donor other than the recipient. The process in option 2 is also collected from a blood donor other than the recipient, but the donor is known to the recipient and is usually a family member or friend. Cross-matching significantly enhances compatibility. It does not detect infection.
22. Answer C. This process eliminates white blood cell functioning, thus, preventing GVHD. Diphenhydramine HCl is an antihistamine. It’s use prior to a blood transfusion decreases the likelihood of a transfusion reaction. Option 2 will not prevent GVHD. Use of acetaminophen prevents and treats the common side effects of blood administration caused by the presence of white blood cells in the transfusion product: fever, headache, and chills.
23. Answer C. Hepatitis B is the most common infection spread via blood transfusion. Donors are screened by a questionnaire that includes symptoms. The donated blood is also tested for infection. The risk of infection with the agents in options 2 and 3 has decreased to approximately 1 in 2 million secondary to donor questioning and donor blood testing. The incidence of West Nile viral transmission is unknown, but donor infection is still relatively rare.
24. Answer C. Type O, Rh negative blood has none of the major antigens and is safely administered to patients of all blood types. It is also known as the universal donor. Premedicating with these agents will not prevent a major transfusion reaction if the blood type and Rh factors of the donor blood are incompatible with the recipient’s blood.
25. Answer B. A red blood cell transfusion is used to correct anemia in patients in which the low red blood cell count must be rapidly corrected. RBC transfusion will not correct a low platelet count. RBC transfusion will not correct a low white blood cell count. Packed RBCs contain very little plasma and, thus, only a small amount of albumin. This amount will not correct low albumin levels.
26. Answer B. This is needed to utilize the correct type of donor blood and to match the donor product with the patient. Incompatible matches would result in severe adverse events and possible death. The tests in options 1 and 3 are unnecessary. The test in option 4 is utilized to determine the patient’s blood type and presence of antibodies to blood antigens. It does not determine donor blood compatibility with the patient.
27. Answer C. Large bore catheters prevent damage to blood components and are less likely to develop clotting problems than a small bore catheter. The nurse should determine the correct device without asking the patient what type has been used before or asking the physician which type he prefers and start the IV.
28. Answer D. A 25 percent solution contains one quarter of a gram per milliliter. Thus, the nurse will administer 4 milliliters to provide a complete gram of albumin. The volume in option 1 would provide 12.5 grams of albumin. The nurse should determine the volume. It is unnecessary to seek the answer from the physician. A 25 percent solution is an acceptable product and can safely be used.
29. Answer C. Many chemotherapeutic drugs are vesicants (highly active corrosive materials that can produce tissue damage even in low concentrations). Extravasations of a vesicant can result in significant tissue necrosis. Administration into a large vein is optimal. CVADs are more expensive than a peripheral IV. Dosing depends on the drug. IV chemotherapeutic agents are not administered at home. They are given in an outpatient or clinic setting if not given during hospitalization.
30. Answer D. Microorganisms that infect CVADs are often coagulase-negative staphylococci, which can be eliminated by antibiotic administration through the catheter. If unsuccessful in eliminating the microorganism, the CVAD must be removed. CVAD use lessens the need for peripheral IV lines and, thus, the risk of infiltration. In this case however, the antibiotics are given to eradicate microorganisms from the CVAD. CVAD use has this effect, but in this case, the antibiotics are given through the CVAD to eliminate the infective agent. The third option would not occur.

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