Chapter 9: Antibiotics [PrepU]

A client has been on an antibiotic for two weeks for treatment of an infection. The client asks the nurse why a superinfection has been caused by this medication. What is the nurse's best response?

"Antibiotics can disrupt the normal bacteria in your body, causing another infection to occur." Rationale: Superinfections are caused when the antibiotic destroys the normal flora within the body and a secondary infection occurs. The infection is caused by a different bacterial or fungal infection.

The health care provider is preparing to order rifampin and pyrazinamide for a female client with active tuberculosis. What question should the provider ask this client before confirming this order?

"Are you pregnant?" Rationale: Pyrazinamide and streptomycin are contraindicated in pregnancy. A regimen of INH, rifampin, and ethambutol is usually used in the treatment of pregnant women.

Penicillins are most effective when used to treat what type of microorganisms?

gram-positive bacteria

A client has been prescribed oral tetracycline. The nurse will instruct the client to take the drug how?

on an empty stomach Rationale: Oral preparations of tetracycline should be administered on an empty stomach 1 hour before or 2 hours after taking a meal or other drugs to maximize absorption. Tetracycline is not absorbed effectively if taken with food or dairy products. The dosage must be distributed around the clock, and not just at bedtime, to increase effectiveness.

The client has been taking a fluoroquinolone and now reports that he has a white patch in his mouth. What is the best response of the nurse?

"You may be experiencing an additional infection. I will discuss this with your health care provider." Rationale: A burning sensation of the mouth or throat may be an indication of a superinfection. It is important the nurse notify the provider. The nurse should not minimize the client's concerns or cause panic.

A client has been prescribed 4 g of sulfamethoxazole/trimethoprim tablets per day. The available drug is in the form of 500 mg. The nurse would administer how many tablets each day?

8 Rationale: The required dosage is 4 g per day. Available drug is in the form of 500 mg. Therefore, eight (4000 mg/500 mg) tablets have to be administered every day.

A nurse is preparing the medical history report of a patient with a urinary tract infection. Which of the following conditions should the nurse identify as one in which the use of cephalosporins is restricted?

Renal disease Rationale: The use of cephalosporins is restricted if the patient has a history of allergies to cephalosporins or penicillins, renal disease, hepatic impairment, bleeding disorder, or pregnancy. Aplastic anemia, headaches, and abdominal cramps are some of the adverse reactions that can be caused by use of cephalosporins.

A middle-aged client is to receive tetracycline for treatment of H. pylori infection, as well as continue with digoxin for a history of heart disease. The nurse will be prepared to monitor the client for which potential condition?

Risk of digoxin toxicity Rationale: When digoxin interacts with tetracyclines, the client is at risk for digoxin toxicity. Respiratory depression is an effect observed when neuromuscular blocking drugs interact with lincosamides. A decrease in the effectiveness of tetracycline is seen when the drug is taken with antacids, dairy products, or iron. An increased risk for bleeding with prolonged clotting times is noted when tetracycline is given with anticoagulants.

A patient has been prescribed oral tetracycline for the treatment of acne. Which of the following must the nurse include in the patient teaching plan?

Take the drug on an empty stomach. Rationale: Oral preparations of tetracycline should be administered on an empty stomach with a full glass of water to maximize absorption. Tetracycline is not absorbed effectively if taken with food, dairy products, or immediately after meals.

Which statement is true in regards to the oral administration of tetracyclines?

Tetracyclines should be administered with a full glass of water. Rationale: Tetracyclines should always be administered with a full glass of water and on an empty stomach (except minocycline and tigecycline may be taken with food).

What event triggers the development of a superinfection?

proliferation of antibiotic-resistant microorganisms Rationale: Superinfection is an infection after the occurrence of a previous infection, typically caused by microorganisms that are resistant to the antibiotics used earlier. None of the other options accurately describe this condition as it is associated with antibiotic-resistant microorganisms.

A nurse is speaking to a 62-year-old female client who has been started on sulfisoxazole, a sulfonamide antibiotic. The nurse should teach this client to contact the health care provider if the client experiences what adverse effect associated with the drug?

skin rash or itching Rationale: Clients taking sulfonamides should be instructed to contact the prescriber if they experience skin rash or itching. These symptoms may indicate a sulfonamide-induced allergic reaction and the need to change or stop the drug.

Which action would the nurse suggest to a client to reduce the risk of photosensitivity from sulfonamide therapy? Select all that apply.

using sunscreen wearing sunglasses wearing protective clothing Rationale: The nurse should suggest avoiding any exposure to sunlight or ultraviolet light (tanning beds, sunlamps) while taking these drugs and for several weeks after completing the course of therapy. This would include wearing sunblock, sunglasses, and protective clothing when exposed to sunlight. Drinking increased fluids is not indicated unless crystalluria is present.

A teenager is admitted to a health care facility for a fungal infection. It has been determined that the infection was present for a long time, but there was no treatment undertaken. The teenager now has a systemic fungal infection for which flucytosine is prescribed. Which would be most important for the nurse to assess before beginning therapy?

weight Rationale: With flucytosine, it is important for the nurse to weigh the teenager because the dosage of the drug is determined by the weight. The teenager has a systemic fungal infection, so inspection of the mouth or assessment of vaginal discharge would not be important. Although it would be important to assess the teenager's hydration status, this is not as important as obtaining the weight.

A 26-year-old female client with a skin infection has been prescribed 400 mg ampicillin to be taken orally. Which instruction should the nurse include in the client teaching plan?

Ampicillin will reduce the effectiveness of birth control pills. Rationale: Ampicillin (also penicillin V) reduces the effectiveness of birth control pills. Increasing a dosage to compensate for a missed dosage should not be done. The client should adhere to the prescribed regimen as strictly as possible. Ampicillin and penicillin V may be taken without regard to meals. The client need not avoid use of skin care products when on penicillin therapy.

A nurse is caring for a patient who has an acute bacterial exacerbation of chronic bronchitis and who has been prescribed telithromycin (Ketek). Before therapy begins, the nurse will assess the patient for a history of which of the following?

Arrhythmias Rationale: Telithromycin is given cautiously in cases of congenital prolongation of the QT interval, uncorrected hypokalemia and hypomagnesemia, and clinically important bradycardia because these are considered PR dysrhythmic conditions.

Beta-lactam antibiotics, such as penicillins and cephalosporins, fight infection by inhibiting development of the causative bacteria. What specific component development do these drugs affect?

Cell wall synthesis Rationale: Beta-lactam antibacterial drugs inhibit synthesis of bacterial cell walls by binding to proteins in bacterial cell membranes. This binding produces a defective cell wall that allows intracellular contents to leak out. These do no affect DNA replication or cell division.

An older adult client, diagnosed with community-acquired pneumonia, has been prescribed aztreonam. What action should the nurse perform before administering the first dose?

Confirm the client's allergy status. Rationale: As with all antibiotics, it is important to assess the client's allergy status prior to drug administration. This is especially important before the initial dose. An IV bolus is unnecessary, and discoloration of urine is not expected. MRSA testing is not relevant to aztreonam administration.

A client who takes zinc daily is diagnosed with a severe infection and is ordered levofloxacin (Levaquin). The nurse is aware that taking these two drugs may have what affect on the antibiotic?

Decreased absorption Rationale: Antacids, iron salts and zinc can cause decreased absorption of the antibiotic. There is no affect on elimination of the antibiotic.

A client who routinely takes antacids has been prescribed tetracycline. The nurse explains to the client that there is an increased risk of which effect related to this combination?

Decreased absorption of tetracycline Rationale: Interaction of antacids with a tetracycline drug causes decreased absorption of tetracycline. Increased action of neuromuscular blocking drugs and increased profound respiratory depression are the result of interaction between neuromuscular blocking drugs and tetracyclines. Increased risk of bleeding is a result of interaction between anticoagulants and tetracyclines.

A nurse is caring for a client daignosed with a serious gram-negative infection prescribed amikacin. Which action should the nurse prioritize while caring for this client?

Do renal tests daily Rationale: The potential for nephrotoxicity and ototoxicity with amikacin is very high, so the drug is used only as long as absolutely necessary. The increased risk of nephrotoxicity requires daily renal tests to monitor for this adverse effect. Another potential is ototoxicity, so monitoring hearing would be more of a priority than assessing the vision daily. Other adverse effects of amikacin are nausea, vomiting, and diarrhea, not constipation.

A client who is being discharged has been instructed to continue with sulfonamide therapy for a week. Which point should the nurse include in the teaching plan to educate the client about the therapy?

Ensure that all follow-up appointments are met. Rationale: The nurse's plan should include educating the client about the importance of keeping the follow-up appointments. The nurse should instruct the client to adhere to the dosage schedule and not discontinue it even if the symptoms of the infection have gone. The client should inform the primary health care provider if fever, skin rash, or nausea occurs during the therapy. The client should be instructed to take the drug on an empty stomach (at least 2 hours before or after a meal) and not just before a meal.

A nurse is caring for a patient who is being administered penicillin. What are the common adverse reactions to penicillin a nurse should assess for?

Inflammation of the tongue and mouth Rationale: Some of the common adverse effects of penicillin are glossitis (inflammation of the tongue), stomatitis (inflammation of the mouth), and gastritis (inflammation of the stomach). Unless severe, the drug may be continued as prescribed and the nurse would intervene to help the patient manage the common adverse reactions. Impaired oral mucous membranes are signs of a fungal superinfection in the oral cavity, whereas severe hypotension and sudden loss of consciousness are signs of an anaphylactic shock; these are not common adverse effects of penicillin and require immediate medical attention.

A client is prescribed isoniazid (INH) for a diagnosis of tuberculosis. Which adverse effect will result in discontinuation of the medication?

Jaundice Rationale: Potentially serious adverse effects of INH include hepatotoxicity. Hepatotoxicity may be manifested by symptoms of hepatitis (e.g., anorexia, nausea, fatigue, malaise, jaundice) or elevated liver enzymes. The nurse reports their development to the health care provider promptly to prevent possible liver failure and death. Weight gain, fever, and arthralgia are not the most known adverse effects of INH.

In which condition present in the client should macrolides be used with caution?

Liver dysfunction Rationale: All macrolides should be used with caution in clients with liver dysfunction. Pre-existing liver disease is a contraindication. Diabetes, hypertension and glaucoma are not contraindicated.

A 40-year-old is being treated for an ear infection with a cephalosporin. Which adverse reactions should the nurse monitor for in the client?

Nausea Rationale: The most common adverse reactions that are caused due to cephalosporin administration include nausea, vomiting, and diarrhea. Cephalosporin does not cause hypotension, chest pain, or excessive tearing; hypotension and chest pain are some of the adverse reactions of disulfiram.

A client is being given a prescription for ciprofloxacin (Cipro) to treat a urinary tract infection. The nurse should warn the client about which of the following common adverse reactions? (Select all that apply.)

Nausea Headache Dizziness Rationale: Common adverse reactions to fluoroquinolones include nausea, vomiting, diarrhea, headache, abdominal pain or discomfort, dizziness, and photosensitivity, especially with lomefloxacin and sparfloxacin treatment.

Michael, 25 years old, has had mitral valve regurgitation since age four, after having rheumatic fever. Michael is planning to go to his dentist to have his teeth cleaned. Because of Michael's history he will need to take antibiotics in conjunction with this procedure to prevent bacteremia. Which class of antibiotics will Michael most likely receive if he has no allergies?

Penicillin Rationale: Penicillin G may also be used as prophylaxis in special patient populations to prevent bacterial endocarditis prior to procedures likely to produce temporary bacteremia, such as dental procedures. These patients include those with prosthetic heart valves, mitral valve prolapse, most congenital heart diseases, and acquired valvular heart disease. It may also be used as prophylaxis in patients with recurrent rheumatic fever or rheumatic heart disease.

A client has been prescribed lomefloxacin (Maxaquin) for a respiratory infection. What must the nurse closely monitor for in this client?

Photosensitivity Rationale: Lomefloxacin may induce serious photosensitivity reactions and should be discontinued at the first sign of rash, redness, or burning sensation on the skin. The drug is not associated with the development of psychosis, anemia, or increased ICP.

A nurse is caring for a patient who has a serious infection. The patient is being treated with combination therapy of a cefazolin and an aminoglycoside. The nurse will be sure to monitor which of the following?

Serum BUN and creatinine levels Rationale: Patients receiving combination therapy of a cefazolin and an aminoglycoside will need to be monitored for nephrotoxicity and therefore would need serum BUN and creatinine levels done. Serum sodium and potassium levels as well as aspartate aminotransferase should be monitored when receiving sodium penicillin G. PT and PTT should be monitored when a patient is receiving aztreonam, a monobactam antibiotic.

After teaching a group of nursing students about sulfonamides, the instructor determines that the teaching was successful when the students choose which medication as an example of a sulfonamide antibiotic? Select all that apply.

Sulfamethoxazole/trimethoprim Silver sulfadiazine Rationale: Silver sulfadiazine (Silvadene) and sulfamethoxazole/trimethoprim (Bactrim) are sulfonamide antibiotics. Amoxicillin is an aminopenicillin. Ciprofloxacin is classified as a fluoroquinolone. Clarithromycin is a macrolide.

A client is being treated for urosepsis with ceftriaxone IV. What assessment finding should prompt the nurse to contact the care provider immediately?

The client has a new onset of jaundice and edema Rationale: Jaundice and edema suggest liver dysfunction, which the nurse should promptly report. Each of the other changes in status warrant the nurse's thoughtful attention and relevant interventions but none requires immediate input from the client's care provider.

A client is taking penicillin for an upper respiratory infection. The client calls the office after 2 days of therapy reporting nausea and abdominal pain. Which would be the best instruction for the nurse to give the client?

These are normal side effects, but if they increase in severity or frequency, you need to contact the office again. Rationale: The client is having an adverse effect from the medication, which is not life threatening. The best advice to the client would be to continue to take the medication as prescribed and report any worsening of the symptoms. The most serious adverse effect of penicillin G is allergic reaction: rash, fever, and wheezing, and possibly anaphylaxis and death. More common adverse effects of penicillin therapy involve the GI tract: nausea, vomiting, diarrhea, abdominal pain, glossitis, stomatitis, gastritis, sore mouth, and furry tongue. These effects are primarily related to the loss of normal flora (naturally occurring bacteria in the body) and subsequent opportunistic infections.

The nurse knows that pseudomembranous colitis is a superinfection of fluoroquinolones, especially when they are administered in high doses, because these medications have what effect in the body?

They disrupt the normal flora of the body. Rationale: Pseudomembranous colitis is a superinfection that occurs when the antibiotic disrupts the normal flora, causing a secondary infection or superinfection.

The nurse is caring for a 23-year-old female client who uses oral contraceptives and has been prescribed ampicillin for treatment of a respiratory infection. What information is most important for the nurse to share with this client?

Use a type of barrier birth control while you are taking this antibiotic. Rationale: Clients taking oral contraceptives should be encouraged to use a barrier type of birth control during penicillin therapy; the penicillin will cause a decreased effectiveness of the contraceptive agent. The client should not be told to stop taking the oral contraceptive. This will not cause a heavier menses. The interaction between oral contraceptives and ampicillin will not cause an increased chance of bleeding, as that interaction is between large doses of penicillins and anticoagulants.

After teaching a group of nursing students about the action of penicillins, the instructor determines that the teaching was effective when the students identify natural penicillins as exerting which type of effect on microorganisms?

bactericidal Rationale: Natural penicillins exert a bactericidal effect on bacteria. Because penicillin targets bacterial cells, it is of no value to treat fungal infections as it is neither fungicidal nor fungistatic. Since it targets the bacterial cell wall to destroy the bacteria, it does not inhibit growth as in bacteriostatic.

A patient with TB has been admitted to a health care facility. When providing instructions for the patient teaching related to antitubercular drugs, which instructions should the nurse provide in order to avoid complications in the patient's GI tract?

Avoid the consumption of alcohol. Rationale: The nurse should instruct the patient to avoid the consumption of alcohol since alcoholism compounds patient's difficulties and complicates the general condition of the patient's gastrointestinal tract. The nurse should instruct the patient to take the prescribed dose of Ethambutol without regard to food and to take the prescribed Pyrazinamide along with food. The nurse should instruct the patient to avoid doubling the dose in case the earlier dose was missed.

A client with a positive sputum culture for TB has been started on streptomycin antitubercular therapy. Upon review of the laboratory results, the nurse notes that the client may be experiencing toxicity if which of the following results is abnormal?

BUN and creatinine Rationale: Streptomycin can cause nephrotoxicity. The nurse would be monitoring the BUN and creatinine levels. Amylase and lipase are related to liver function. Streptomycin does not affect the electrolytes or blood cell counts.

What potential adverse reaction is most likely to develop during cefazolin therapy?

Gastrointestinal upset Rationale: Adverse effects to cefazolin and the other cephalosporins are similar to those of most other antibiotics: abdominal pain, diarrhea, gastritis, nausea, and vomiting because of its effect on the gastrointestinal lining. Integumentary, neurological, and blood pressure changes are atypical.

A male client is placed on an IV regimen of aztreonam. The nurse would expect the health care provider to order which laboratory test?

Liver function Rationale: Aztreonam, imipenem, meropenem, and ertapenem may cause abnormalities in liver function test results (i.e., elevated alanine and aspartate aminotransferases [ALT and AST] and alkaline phosphatase), but hepatitis and jaundice rarely occur.

While administering aminoglycosides to clients, the nurse must be aware of what toxicities that can result from their use? (Select all that apply.)

Nephrotoxicity Ototoxicity Neurotoxicity Rationale: Serious adverse reactions of aminoglycosides include nephrotoxicity, ototoxicity, and neurotoxicity. A nurse recognizing these can greatly reduce permanent damage to the client's hearing, kidneys, and nerves.

Which of the following should a nurse carefully monitor in a patient who has been administered cephalosporin as well as aminoglycosides for a wound infection?

Nephrotoxicity Rationale: When cephalosporin is administered with aminoglycosides, it increases the risk for nephrotoxicity and should be closely monitored. Nausea is an adverse reaction of cephalosporins in patients with gastrointestinal tract infection. The risk of bleeding increases when cephalosporin is administered with oral anticoagulants. Risk for respiratory difficulty increases if alcohol is consumed within 72 hours after certain cephalosporin administration.

When administering aminoglycosides, the nurse must be aware of which of the following adverse reactions?

Ototoxicity & nephrotoxicity Rationale: After parenteral administration, aminoglycosides are widely distributed in extracellular fluid and reach therapeutic levels in blood, urine, bone, inflamed joints, and pleural and ascitic fluids. They accumulate in high concentrations in the proximal renal tubules of the kidney leading to acute tubular necrosis. This damage to the kidney is termed nephrotoxicity. They also accumulate in high concentrations in the inner ear, damaging sensory cells in the cochlea and the vestibular apparatus. This damage to the inner ear is termed ototoxicity.

The nurse is preparing to administer sulfadiazine to a client who is also taking warfarin. The nurse would be alert for which potential adverse effect?

Prolonged clotting times Rationale: When warfarin and sulfonamides are given concomitantly, an increase in action of the anticoagulant is seen, leading to an increase in clotting time, such as PT/INR, and an increased risk of bleeding. An increased risk of infection and a decrease in the white blood cell count would occur when a sulfonamide is given with methotrexate. The combination of warfarin and sulfonamide does not impact the effect of the antibiotic.

A client undergoing penicillin therapy shows improvement and confirms feeling better. Which intervention is the nurse most likely to perform in such a situation?

Record assessments on client's chart. Rationale: When the client shows and verbally confirms improved health, it should be recorded on the client's chart. If the patient's condition has improved, the client will show an increased appetite, but there is no need to instruct the client to increase dietary intake. The primary health provider need not be informed about the condition immediately unless the client shows signs of deterioration or complications. The nurse should inquire about previous drug allergies before the start of therapy.

A client in the critical care unit is receiving aminoglycosides for an infectious process. What does the nurse need to monitor?

Renal function tests Rationale: Because critically ill clients are at high risk for development of nephrotoxicity and ototoxicity with aminoglycosides, guidelines for safe drug use should be strictly followed. Renal function should be monitored to assess for needed dosage reductions in clients with renal dysfunction who are receiving aminoglycosides.

A middle-aged patient has been prescribed tetracycline as part of his Prevpac for the treatment of H. pylori. The patient has a history of atrial fibrillation which is being treated with digitalis drugs. Given his history and current medications, the patient is at risk for which of the following conditions?

Risk of toxicity Rationale: When digitalis drugs interact with tetracyclines, the patient is at a risk for toxicity. Respiratory depression is an effect observed when neuromuscular-blocking drugs interact with lincosamides. Increase in serum levels is observed when digoxin interacts with macrolides. Increase in serum theophylline level occurs when theophylline interacts with macrolides.

A patient with TB is admitted to a health care facility. The nurse is required to administer an antitubercular drug through the parenteral route to this patient. Which of the following precautions should the nurse take when administering frequent parenteral injections?

Rotate injection sites for frequent parenteral injections. Rationale: The nurse should be careful to rotate injection sites when administering frequent parenteral injections. At the time of each injection, the nurse inspects previous injection sites for signs of swelling, redness, and tenderness. The nurse should monitor any signs of liver dysfunction monthly in patients who are being administered antitubercular drugs. The nurse should ensure that pyridoxine, and not streptomycin, is administered to the patient to promote nutrition, but this is only administered if the patient has been living in impoverished conditions and is malnourished. The nurse should monitor patient's vital signs every four hours and not once every morning.

The nurse is caring for a client who is receiving erythromycin. What assessment finding suggests that the client is experiencing an adverse effect of the drug?

The client is uncharacteristically euphoric. Rationale: It is important to assess the client's psychosocial responses that are adverse effects of erythromycin, such as crying, laughing, and altered thought processes. Dry cough, incontinence, and hypotension are not associated with the use of erythromycin.

A client, being treated for latent tuberculosis (TB) on an out-client basis, tells the nurse, "I've been feeling pretty good lately, so I haven't actually been all that consistent with taking my drugs." Subsequent health education by the nurse should focus on what subject?

The need to consistently take the prescribed drugs in order to cure TB Rationale: Consistent adherence to treatment is imperative to ensure successful treatment of TB. Nonadherence leads to resistance and unsuccessful treatment, not increased adverse effects. Nonadherence has no relationship with matching dosage with signs and symptoms. Antivirals are ineffective against TB.

The nurse is giving discharge instructions to a woman who will be taking amoxicillin for treatment of acute otitis media. The nurse teaches the client that which symptom indicates the development of a superinfection and should be reported to the physician?

Vaginal itching and discharge Rationale: A vaginal infection in a client who is taking amoxicillin is an example of a superinfection. The nausea and abdominal pain are adverse effects of the medication, and swelling and itching of the throat are an example of possible allergy to the drug.

A 49-year-old client is diagnosed with TB. The client has a history of alcoholism but has been sober for 3 months now. The client has been prescribed INH. What should the nurse ensure is obtained before initiating the therapy?

baseline liver function test values Rationale: For a TB client, the nurse should obtain baseline liver function test values and schedule serial liver function tests throughout therapy. In addition, a nurse should ensure a baseline A1C evaluation for clients who are diabetics, because INH may cause hyperglycemia. Clients with preexisting anemias should have a baseline complete blood count (CBC), because they are at risk for hematologic disorders. For clients with a history of seizures, perform a baseline neurologic examination. Also assess baseline visual acuity. All other assessments such as height, weight, serum glucose level, and bone mass are not applicable to INH therapy.

A 54-year-old woman with a history of osteoporosis has been prescribed ciprofloxacin for recurrent cystitis. Because of the patient's history, the nurse would be sure to discuss with the woman the use of

food containing iron or calcium Rationale: Patients who take ciprofloxacin should avoid taking the drug with food that contains iron, calcium, magnesium, and other cations because the presence of these elements may reduce the bioavailability of ciprofloxacin. Because the woman has a history of osteoporosis, she is very likely taking a calcium supplement. Alcohol and nicotine should be avoided while on any drug therapy. Grapefruit juice is not known to interact with ciprofloxacin.

After teaching a group of students about the indications for use for aminoglycosides, the instructor determines that the teaching was successful when the students identify which type of infection as a primary indication?

gram-negative infections Rationale: Aminoglycosides are used primarily in the treatment of infections caused by gram-negative microorganisms. Aminoglycosides are not effective on gram-positive bacteria. Since aminoglycosides are antibacterial, they are not effective on fungal or viral infections.

The nursing student read about a disease called Hansen's disease, which is caused by the bacterium Mycobacterium leprae and is treated with many of the same drugs as are used for TB. The student learned that another name for Hansen's disease is which?

leprosy Rationale: Leprosy, also referred to as Hansen's disease, is caused by the bacterium Mycobacterium leprae. Cholera is caused by the virus vibrio. Listeriosis is caused by Listeria monocytogenes. Leptospirosis is caused by a bacteria called Leptospira.