A nurse is educating a client who has been prescribed amoxicillin for a sinus infection.
The client asks, “Why do I have to take this drug three times a day?” What is the best response by the nurse?
“This drug has a short half-life, so it needs to be taken frequently to maintain effective levels in your body.”
“This drug has a high minimum bactericidal concentration, so it needs to be taken frequently to kill the bacteria.”
“This drug has a low therapeutic index, so it needs to be taken frequently to avoid toxicity.”
“This drug has a narrow spectrum of activity, so it needs to be taken frequently to target the specific bacteria."
The Correct Answer is A
This drug has a short half-life, so it needs to be taken frequently to maintain effective levels in your body. The half-life of amoxicillin is 61.3 minutes, which means that half of the drug is eliminated from the body in about an hour. To keep a constant amount of the drug in the blood and tissues, it needs to be taken every 8 hours or three times a day.
Choice B is wrong because the minimum bactericidal concentration (MBC) is the lowest concentration of an antibiotic that kills 99.9% of bacteria.
Amoxicillin has a low MBC, which means it is effective at killing bacteria at low doses.
Choice C is wrong because the therapeutic index (TI) is the ratio of the toxic dose to the effective dose of a drug.
Amoxicillin has a high TI, which means it has a wide margin of safety and is unlikely to cause toxicity.
Choice D is wrong because the spectrum of activity refers to the range of bacteria that an antibiotic can kill or inhibit.
Amoxicillin has a broad spectrum of activity, which means it can target many types of bacteria, including gram-positive and gram-negative ones.
Normal ranges for amoxicillin are 5 to 25 mcg/mL for peak levels and less than 0.5 mcg/mL for trough levels.
Peak levels are measured 1 to 2 hours after taking the drug, and trough levels are measured just before the next dose.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is ["A","B","C"]
Explanation
Empiric therapy with a broad-spectrum antimicrobial agent is indicated for situations when the causative microorganism is unknown, when the infection is severe or life-threatening, and when there is a need to cover multiple pathogens.
Choice D is wrong because empiric therapy with a broad-spectrum antimicrobial agent is not indicated for situations when there is a risk of resistance.On the contrary, this approach can drive antimicrobial overuse and resistance and should be accompanied by a commitment to de-escalation and antimicrobial stewardship.
Choice E is wrong because empiric therapy with a broad-spectrum antimicrobial agent is not indicated for situations when there is a synergistic effect between two or more agents.
Synergistic effect means that the combined effect of two or more agents is greater than the sum of their individual effects.
This may be desirable in some cases, but it is not a reason to use empiric therapy with a broad-spectrum antimicrobial agent.
Correct Answer is B
Explanation
Nitrofurantoin is considered a narrow-spectrum drug because it is effective against only a limited range of bacteria, mainly gram-negative bacteria that cause urinary tract infections.
Some additional explanations are:
Choice A is wrong becauseCiprofloxacin is a broad-spectrum drug that can affect a wide range of bacteria, both gram-positive and gram-negative.
Choice C is wrong becauseTrimethoprim-sulfamethoxazole is also a broad-spectrum drug that can inhibit the growth of many types of bacteria, including some gram-positive and gram-negative bacteria.
Choice D is wrong because None of them is incorrect because nitrofurantoin is a narrow-spectrum drug as explained above.
Normal ranges for urinary tract infection microorganisms are:
• Escherichia coli: less than 10^5 CFU/mL
• Other bacteria: less than 10^4 CFU/mL
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.