Question 1
A 68-year-old female patient with a history of type 2 diabetes mellitus and chronic kidney disease (stage 3) presents to the clinic with symptoms of a urinary tract infection (UTI). Urine culture confirms E. coli sensitive to multiple antibiotics. Considering her renal impairment, which of the following antibiotics is most appropriate for her condition?
A) Ciprofloxacin
B) Nitrofurantoin
C) Tetracycline
D) Gentamicin
E) Amoxicillin
Rationale: This drug is the correct choice because it is specifically indicated for the treatment of UTIs and is safe in patients with mild to moderate renal impairment (though caution or avoidance is advised in patients with a GFR 30 mL/min). Ciprofloxacin and Gentamicin require dose adjustments in renal impairment and carry a higher risk of nephrotoxicity. Tetracycline is not a first-line agent for UTIs. Amoxicillin may be used but is less preferred compared to Nitrofurantoin for uncomplicated UTIs, especially without testing for susceptibility.
Question 2
A 45-year-old man with no significant medical history is diagnosed with community-acquired pneumonia. He is allergic to penicillin, experiencing anaphylaxis in the past. Which of the following antibiotics would be the most appropriate initial therapy?
A) Amoxicillin
B) Azithromycin
C) Piperacillin/Tazobactam
D) Ceftriaxone
E) Vancomycin
Rationale: This drug is appropriate for patients with community-acquired pneumonia who have a penicillin allergy. It covers the necessary pathogens and does not cross-react with penicillins. Amoxicillin and Piperacillin/Tazobactam are contraindicated due to the patient’s penicillin allergy. Ceftriaxone, a cephalosporin, generally has a low cross-reactivity with penicillins, but caution is advised in patients with a history of anaphylaxis to penicillin. Vancomycin is more appropriate for MRSA coverage and not a first-line for community-acquired pneumonia.
Question 3
A patient is diagnosed with an uncomplicated skin and soft tissue infection caused by methicillin-resistant Staphylococcus aureus (MRSA). Which of the following antibiotics is the best choice for outpatient treatment?
A) Vancomycin
B) Daptomycin
C) Doxycycline
D) Cefazolin
E) Meropenem
Rationale: This drug is an appropriate choice for outpatient treatment of uncomplicated skin and soft tissue infections caused by MRSA due to its oral availability, safety profile, and effectiveness against MRSA. Vancomycin and Daptomycin are effective against MRSA but are typically used in more severe infections and require intravenous administration. Cefazolin is ineffective against MRSA, and Meropenem is a broad-spectrum antibiotic that is unnecessary for uncomplicated skin infections and is reserved for severe, hospitalized cases.
Question 4
A 55-year-old female patient is diagnosed with Clostridioides difficile infection (CDI) after a course of clindamycin for a dental infection. Which of the following is the preferred initial treatment for a first episode of mild to moderate CDI?
A) Metronidazole
B) Vancomycin
C) Fidaxomicin
D) Rifaximin
E) Bacitracin
Rationale: This drug (oral) is the preferred treatment for the first episode of mild to moderate Clostridioides difficile infection (CDI), as recommended by guidelines. Metronidazole is no longer recommended as first-line therapy due to lower efficacy compared to vancomycin and fidaxomicin. Fidaxomicin is also a recommended option but often reserved for certain cases due to cost. Rifaximin is typically used as a follow-up treatment in specific cases, not initial therapy. Bacitracin is not effective for treating CDI.
Question 5
A 3-year-old child with otitis media is unable to take oral medications due to vomiting. Which of the following antibiotics is most appropriate for parenteral administration in this situation?
A) Amoxicillin
B) Ceftriaxone
C) Azithromycin
D) Clindamycin
E) Doxycycline
Rationale: This drug is appropriate for parenteral administration in a child with otitis media who cannot tolerate oral medications. It provides broad coverage suitable for the typical pathogens causing otitis media. Amoxicillin is the first-line oral treatment for otitis media but is not suitable for a patient who is vomiting. Azithromycin and Clindamycin can be used in cases of penicillin allergy but are typically given orally. Doxycycline is not recommended in children under 8 years old due to the risk of tooth discoloration.
Question 6
A patient with cystic fibrosis presents with a Pseudomonas aeruginosa pulmonary infection. Which of the following antibiotics is considered first-line therapy for this condition?
A) Tobramycin inhalation
B) Ciprofloxacin
C) Meropenem
D) Vancomycin
E) Amoxicillin/Clavulanate
Rationale: This drug (inhalation) is considered first-line therapy for Pseudomonas aeruginosa pulmonary infections in patients with cystic fibrosis due to its ability to deliver high concentrations of the antibiotic directly to the site of infection, minimizing systemic toxicity. Ciprofloxacin is an alternative, especially in oral form, for managing Pseudomonas infections but is generally considered after inhaled therapies. Meropenem may be used in severe cases requiring IV therapy. Vancomycin and Amoxicillin/Clavulanate are not effective against Pseudomonas aeruginosa.
Question 7
A patient is being treated for Lyme disease with Doxycycline. Which of the following is an important counseling point for this medication?
A) Avoid dairy products while taking this medication.
B) It may cause significant drowsiness; do not drive or operate heavy machinery.
C) Use sunscreen and avoid prolonged sun exposure as this medication can increase sun sensitivity.
D) Take with a full glass of water right before bed.
E) It can cause a black hairy tongue as a side effect.
Rationale: This drug can increase photosensitivity, making the skin more susceptible to sunburn. Patients should be counseled to use sunscreen and avoid prolonged sun exposure. Avoiding dairy products is more relevant to tetracyclines’ absorption, but it’s not as critical as sun protection for doxycycline. Drowsiness is not a common side effect of doxycycline. Taking with a full glass of water is recommended to avoid esophageal irritation, but it’s not specific to bedtime administration. A black hairy tongue is a possible but less common side effect and not as important as the risk of photosensitivity.
Question 8
A 60-year-old male with a prosthetic heart valve is scheduled for dental surgery. To prevent endocarditis, which of the following antibiotics should be administered prophylactically?
A) Amoxicillin
B) Vancomycin
C) Metronidazole
D) Ciprofloxacin
E) Clindamycin
Rationale: This drug is recommended as the first-choice oral antibiotic for prophylaxis against infective endocarditis prior to dental procedures in patients with high-risk conditions, such as those with prosthetic heart valves. It is preferred for its efficacy and safety profile. Vancomycin or Clindamycin may be used in individuals who have a serious allergy to penicillins or amoxicillin. Metronidazole and Ciprofloxacin are not recommended for this indication due to their spectrum of activity not being as targeted for the typical oral flora involved in endocarditis.
Question 9
A patient presents with a severe soft tissue infection and is suspected to have been bitten by a human. Which of the following antibiotics is most appropriate to cover for the polymicrobial nature of human bite wounds?
A) Amoxicillin/Clavulanate
B) Doxycycline
C) Cefazolin
D) Metronidazole
E) Trimethoprim/Sulfamethoxazole
Rationale: This drug is the best choice for treating human bite wounds due to its broad-spectrum activity that covers both aerobic and anaerobic bacteria commonly found in human saliva. It addresses the polymicrobial nature of such infections effectively. Doxycycline, Cefazolin, Metronidazole, and Trimethoprim/Sulfamethoxazole have narrower spectra of activity and may not cover all pathogens involved in a human bite infection.
Question 10
A 25-year-old female with no significant medical history presents with a 3-day history of dysuria, frequency, and urgency. Urinalysis is positive for nitrites and leukocyte esterase. Which of the following is the most appropriate first-line antibiotic for uncomplicated cystitis in this patient?
A) Nitrofurantoin
B) Levofloxacin
C) Amoxicillin
D) Cephalexin
E) Fosfomycin
Rationale: This drug is recommended as first-line therapy for uncomplicated cystitis due to its efficacy, safety profile, and low risk of inducing antibiotic resistance. It specifically targets the urinary tract and is suitable for most uncomplicated UTIs. Levofloxacin, a fluoroquinolone, is reserved for more complicated cases or when first-line agents are contraindicated due to its broader spectrum and risk of resistance. Amoxicillin and Cephalexin are less preferred due to higher resistance rates. Fosfomycin is a single-dose alternative but generally reserved for cases where other antibiotics cannot be used.