Lehne 9th Edition Chapter 86: Bacteriostatic Inhibitors of Protein Synthesis: Tetracyclines, Macrolides, and Others

11. A patient is taking erythromycin ethylsuccinate for a chlamydial infection and develops vaginal candidiasis. The prescriber orders ketoconazole to treat the superinfection. What will the nurse do? a. Administer the erythromycin and the ketoconazole as ordered. b. Contact the provider to discuss changing to a different antifungal medication. c. Contact the provider to discuss increasing the dose of erythromycin. d. Contact the provider to suggest using erythromycin stearate.

ANS: B Erythromycin can prolong the QT interval when present in large concentrations. When erythromycin is combined with a CYP3A4 inhibitor, such as ketoconazole, the risk of sudden cardiac death increases fivefold. The nurse should discuss changing the antifungal medication to one that is not a CYP3A4 inhibitor. It is not correct to give the ketoconazole without questioning the order. Increasing the dose of erythromycin would increase the risk of QT prolongation. Changing to a different preparation of erythromycin would not alter the risk.

17. A nurse is teaching a nursing student about dalfopristin/quinupristin [Synercid]. Which statement by the student indicates an understanding of the teaching? a. "Patients should stop taking the drug if they experience joint and muscle pain." b. "Patients taking this drug should have blood tests performed frequently." c. "Patients who are allergic to penicillin should not take this drug." d. "This drug will be administered intravenously over a 30- to 60-minute period."

ANS: B Patients taking dalfopristin/quinupristin should have blood levels measured twice the first week and then weekly thereafter to assess for hepatotoxicity. Joint and muscle pain are not an indication for withdrawing the drug. There is no cross-sensitivity to penicillin. The drug is given intravenously over a period of at least 1 hour.

6. A patient is to begin taking doxycycline to treat a rickettsial infection. Which statement by the patient indicates a need for teaching about this drug? a. "I should consult my provider before using laxatives or antacids while taking this drug." b. "I should not take a calcium supplement or consume dairy products with this drug." c. "I should take this drug with food to ensure more complete absorption." d. "If I get diarrhea, I should stop taking the drug and let my provider know immediately."

ANS: C Absorption of tetracyclines is reduced in the presence of food. The tetracyclines form insoluble chelates with calcium, iron, magnesium, aluminum, and zinc, so patients should not take tetracyclines with dairy products, calcium supplements, or drugs containing these minerals. Patients who experience diarrhea should stop taking the drug and notify the provider so they can be tested for C. difficile infection.

15. A patient develops CDAD. Which antibiotic is recommended for treating this infection? a. Chloramphenicol b. Clindamycin [Cleocin] c. Linezolid [Zyvox] d. Vancomycin

ANS: D Vancomycin and metronidazole are the drugs of choice for treating CDAD.

13. A patient received 500 mg of azithromycin [Zithromax] at 0800 as a first dose. What are the usual amount and time of the second dose of azithromycin? a. 250 mg at 2000 the same day b. 500 mg at 2000 the same day c. 250 mg at 0800 the next day d. 500 mg at 0800 the next day

ANS: C Azithromycin generally is given as 500 mg on the first day and then 250 mg/day for the next 4 days, so the second dose would be 24 hours after the first dose.

10. A child with an upper respiratory infection caused by B. pertussis is receiving erythromycin ethylsuccinate. After 2 days of treatment, the parent asks the nurse why the child's symptoms have not improved. Which response by the nurse is correct? a. "Erythromycin eliminates the bacteria that causes the infection, but not the toxin that causes the symptoms." b. "We may need to add penicillin or another antibiotic to increase the antimicrobial spectrum." c. "We will need to review the culture sensitivity information to see whether a different antibiotic is indicated." d. "Your child may have developed a suprainfection that we need to culture and treat."

ANS: A Erythromycin is the drug of first choice for treating pertussis infections. Because symptoms are caused by a bacterial toxin and not by the bacteria itself, the drug eliminates the bacteria but does little to alter the course of the disease. It is given to lower infectivity. It is not necessary to add another antibiotic, review the sensitivity information, or look for a suprainfection.

14. Which side effect of clindamycin [Cleocin] causes the most concern and may warrant discontinuation of the drug? a. Diarrhea b. Headache c. Nausea d. Vomiting

ANS: A CDAD is a serious, sometimes fatal suprainfection associated with clindamycin. Patients with diarrhea should notify their prescriber immediately and discontinue the drug until this condition has been ruled out. Headache, nausea, and vomiting do not warrant discontinuation of the drug and are not associated with severe side effects.

12. A nurse is providing teaching for a patient who will begin taking clarithromycin ER [Biaxin XL] to treat an Helicobacter pylori infection. Which statement by the patient indicates understanding of the teaching? a. "I may experience distorted taste when taking this medication." b. "I should take 1 tablet twice daily for 10 days." c. "I should take this medication on an empty stomach." d. "This medication does not interact with other drugs."

ANS: A Clarithromycin is available in an extended-relief preparation as Biaxin XL. Biaxin can cause distortion of taste, so patients should be warned of this side effect. Biaxin XL should be taken once and not twice daily. Biaxin should be taken with food. Biaxin interacts with other drugs by inhibiting hepatic metabolism of those drugs.

2. A pregnant adolescent patient asks the nurse whether she should continue to take her prescription for tetracycline [Sumycin] to clear up her acne. Which response by the nurse is correct? a. "Tetracycline can be harmful to the baby's teeth and should be avoided." b. "Tetracycline is safe to take during pregnancy." c. "Tetracycline may cause allergic reactions in pregnant women." d. "Tetracycline will prevent asymptomatic urinary tract infections."

ANS: A Tetracyclines can cause discoloration of deciduous teeth of infants if taken by the mother after the fourth month of gestation. Tetracyclines should not be given to pregnant women. Tooth discoloration can be prevented if the drugs are not taken by pregnant women or by children under 8 years of age. Tetracycline is not appropriate for a pregnant patient. Pregnancy does not precipitate an allergic response to tetracycline. Tetracycline should not be used to prevent urinary tract infections (UTIs), especially in pregnant women.

1. A nurse is providing education about tetracycline [Sumycin]. Which statement by the patient best demonstrates understanding of the administration of this medication? a. "I should not take this medication with milk or other dairy products." b. "I should not worry if I experience an acnelike rash with this medication." c. "I should take an antacid, such as Tums, if I experience gastrointestinal distress." d. "I should take this antibiotic with a calcium supplement to improve absorption."

ANS: A The patient should avoid taking the medication with dairy products to help prevent chelation. An acnelike reaction would indicate an allergic response. Taking the medication with calcium-containing antacids or supplements should be avoided, because this also leads to chelation.

Which infection(s) may be treated with linezolid [Zyvox])? (Select all that apply.) a. Community-acquired pneumonia (CAP) that is penicillin sensitive b. Nosocomial pneumonia caused by methicillin-sensitive Staphylococcus aureus (MSSA) c. Pneumonias caused by Mycoplasma avium d. Superficial methicillin-resistant Staphylococcus aureus skin infections (MRSA) e. Vancomycin-resistant infections

ANS: A, B, E Linezolid is indicated for CAP caused by PCN-sensitive strains of Streptococcus pneumoniae, nosocomial pneumonia caused by MSSA and MRSA, and vancomycin-resistant enterococcal (VRE) infections. It is not recommended for M. avium infections or for superficial skin infections caused by MRSA.

Tetracyclines are considered first-line drugs for which disorder(s)? (Select all that apply.) a. Chlamydia trachomatis cervicitis b. Clostridium difficile diarrhea c. Lyme disease d. Methicillin-resistant Staphylococus aureus skin infections e. Typhus fever

ANS: A, C, E Tetracyclines are drugs of first choice for rickettsial diseases, infections caused by C. trachomatis, brucellosis, cholera, Mycoplasma pneumonia, Lyme disease, anthrax, and gastric infections caused by H. pylori. They are not first-line drugs for CDAD or MRSA skin infections.

19. A patient with severe community-acquired pneumonia has been prescribed telithromycin [Ketek]. Which aspect of the patient's medical history is of concern to the nurse? a. Anemia b. Myasthenia gravis c. Renal disease d. Strep. pneumoniae infection

ANS: B Telithromycin is a macrolide antibiotic used only for CAP. Patients with myasthenia gravis may experience rapid muscle weakness after taking the drug, and some have died from respiratory failure, so patients with MG should not take this drug. This drug does not have significant myelosuppression, so anemia is not a concern. The drug causes liver injury, so liver disease, and not renal disease, is a concern. Telithromycin is indicated for treatment of S. pneumonia.

4. A patient is diagnosed with periodontal disease, and the provider orders oral doxycycline [Periostat]. The patient asks the purpose of the drug. What is the nurse's response? a. "It is used because of its anti-inflammatory effects." b. "It inhibits collagenase to protect connective tissue in the gums." c. "It reduces bleeding and the pocket depth of oral lesions." d. "It suppresses bacterial growth in the oral mucosa."

ANS: B Two tetracyclines are used for periodontal disease. Doxycycline inhibits collagenase, which destroys connective tissue in the gums. It is not used for anti-inflammatory effects. Minocycline is used to reduce bleeding and pocket depth and to inhibit bacterial growth.

7. A patient who is taking doxycycline for a serious infection contacts the nurse to report anal itching. The nurse will contact the provider to discuss: a. adding an antihistamine to the patient's drug regimen. b. ordering liver function tests to test for hepatotoxicity. c. prescribing an antifungal drug to treat a superinfection. d. testing the patient for a C. difficile secondary infection.

ANS: C A superinfection occurs secondary to suppression of drug-sensitive organisms. Overgrowth with fungi, especially Candida albicans, is common and may occur in the mouth, pharynx, vagina, and bowel. Anal itching is a sign of such an infection, not a sign of hepatotoxicity. Antihistamines will not treat the cause. C. difficile is characterized by profuse, watery diarrhea.

3. A patient recently began receiving clindamycin [Cleocin] to treat an infection. After 8 days of treatment, the patient reports having 10 to 15 watery stools per day. What will the nurse tell this patient? a. The provider may increase the clindamycin dose to treat this infection. b. This is a known side effect of clindamycin, and the patient should consume extra fluids. c. The patient should stop taking the clindamycin now and contact the provider immediately. d. The patient should try taking Lomotil or a bulk laxative to minimize the diarrheal symptoms.

ANS: C Clostridium difficile-associated diarrhea (CDAD) is the most severe toxicity of clindamycin; if severe diarrhea occurs, the patient should be told to stop taking clindamycin immediately and to contact the provider so that treatment with vancomycin or metronidazole can be initiated. Increasing the dose of clindamycin will not treat this infection. Consuming extra fluids while still taking the clindamycin is not correct, because CDAD can be fatal if not treated. Taking Lomotil or bulk laxatives only slows the transit of the stools and does not treat the cause.

9. A 6-week-old infant who has not yet received immunizations develops a severe cough. While awaiting nasopharyngeal culture results, the nurse will expect to administer which antibiotic? a. Clindamycin [Cleocin] b. Doxycycline [Vibramycin] c. Erythromycin ethylsuccinate d. Penicillin G

ANS: C Erythromycin is the drug of first choice for infections caused by Bordetella pertussis, the causative agent of whooping cough. Infants who have not received their first set of immunizations are at increased risk of pertussis. Clindamycin, doxycycline, and penicillin are not recommended.

16. A patient who has been taking linezolid [Zyvox] for 6 months develops vision problems. What will the nurse do? a. Reassure the patient that this is a harmless side effect of this drug. b. Tell the patient that blindness is likely to occur with this drug. c. Tell the patient that this symptom is reversible when the drug is discontinued. d. Tell the patient to take tyramine supplements to minimize this effect.

ANS: C Linezolid is associated with neuropathy, including optic neuropathy. This is a reversible effect that will stop when the drug is withdrawn. Reassuring the patient that this is a harmless side effect is not correct. It is not an indication that blindness will occur. Tyramine supplements are not indicated.

5. To prevent yellow or brown discoloration of teeth in children, tetracyclines should not be given: a. to children once the permanent teeth have developed. b. to patients taking calcium supplements. c. to pregnant patients after the fourth month of gestation. d. with dairy products or antacids.

ANS: C Tetracyclines bind to calcium in developing teeth, resulting in yellow or brown discoloration. They should not be given to pregnant women after the fourth month of gestation, because they will cause staining of deciduous teeth in the fetus. In children, discoloration occurs when tetracyclines are given between the ages of 4 and 8 years, because this is when permanent teeth are developing. Tetracycline binds with calcium, so absorption is diminished when the drug is given with calcium supplements, dairy products, or calcium-containing antacids; however, this does not affect tooth development.

8. A hospitalized patient who is taking demeclocycline [Declomycin] reports increased urination, fatigue, and thirst. What will the nurse do? a. Contact the provider to report potential toxic side effects. b. Notify the provider to discuss changing the medication to doxycycline. c. Perform bedside glucometer testing to evaluate the serum glucose level. d. Provide extra fluids and reassure the patient that these are expected side effects.

ANS: D Demeclocycline stimulates urine flow and sometimes is used to treat patients with syndrome of inappropriate antidiuretic hormone secretion (SIADH). The patient should be reassured that increased urination, fatigue, and thirst are known side effects of demeclocycline. It is not correct to notify the provider of toxic side effects or to request another tetracycline. Glucometer testing is not necessary, because the increased urination is not related to an elevated blood glucose level.

18. A child has been receiving chloramphenicol for a Neisseria meningitidis central nervous system (CNS) infection. The nurse administers the dose and subsequently notes that the child has vomited and appears dusky and gray in color. The child's abdomen is distended. What will the nurse do? a. Contact the provider for an order to obtain a chloramphenicol level. b. Notify the provider that the child's meningitis is worsening. c. Recognize this as initial signs of a C. difficile infection. d. Stop the infusion immediately and notify the provider.

ANS: D Gray syndrome is a potentially fatal toxicity associated with chloramphenicol use. When symptoms occur, the drug should be stopped immediately. Lower chloramphenicol levels may prevent gray syndrome, but lowering the dose will not stop symptoms once they have appeared. These are not signs of worsening meningitis or a C. difficile infection.