Question 1

Identify a true statement about the fluoroquinolones.

Accepted Answer

The fluoroquinolones are synthetic antimicrobials that have a broad spectrum of bactericidal activity, especially against gram-negative organisms. One of their advantages, over other broad-spectrum antibiotics, is that they are well absorbed after oral administration.

Question 2

Which of the following is an alternative for benzathine penicillin as therapy for syphilis infections?

Accepted Answer

Benzathine penicillin administered as a single dose by IM injection is standard therapy for syphilis infections. Alternatives are ceftriaxone IM single dose or doxycycline administered PO twice per day for 14 days.

Question 3

Identify the penicillin that has the broadest spectrum among the following.

Accepted Answer

Mezlocillin sodium (Mezlin) is a fourth-generation penicillin that has increased effectiveness compared to the previous generations of drugs.

Question 4

Jacob,before a colorectal surgery,was given a drug to be taken orally so that the number of bacteria in his bowel could reduce before the surgery.Which of the following is most likely the antibiotic administered to Jacob?

Accepted Answer

The aminoglycosides are poorly absorbed from the GI tract, and this effect is used to advantage before intestinal surgery. Large doses are given orally before abdominal surgery to reduce the number of intestinal bacteria and sterilize the bowel.

Question 5

Lillian was suffering from Lyme disease.She was given Biaxin for her treatment.Which of the following is the adverse effect that Lillian is most likely to suffer due to this medication?

Accepted Answer

The newer derivatives of macrolide antibiotics include azithromycin, clarithromycin, and dirithromycin. The most common adverse effect of these drugs is gastrointestinal irritation.

Question 6

Upper respiratory infections are most commonly caused by _____.

Accepted Answer

Infections of the nasal cavity (sinusitis), ear (otitis media), and throat (pharyngitis) are most commonly caused by Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae, and Moraxella catarrhalis.

Question 7

Identify an accurate statement about sulfonamides.

Accepted Answer

Bacteria have an essential requirement for paraaminobenzoic acid, which is used in the synthesis of folic acid. The sulfonamides are competitive antagonists of paraaminobenzoic acid. The sulfonamides block the synthesis of folic acid, which subsequently inhibits bacterial growth, producing a bacteriostatic effect.

Question 8

Which of the following is a correct statement about antimicrobial drugs?

Accepted Answer

Metronidazole is an antimicrobial drug that is bactericidal to both anaerobic bacteria and protozoa. When mixed with alcohol, metronidazole may cause a disulfiram-like reaction.

Question 9

Which of the following penicillins has the narrowest spectrum?

Accepted Answer

Penicillin V (V-Cillin, Pen-Vee K) is a first-generation penicillin. The effectiveness of these drugs increase with each successive generation.

Question 10

Steven,a 40-year-old man,is being treated for tuberculosis.During his recent checkup,the physician noticed that the durations of action of the drugs administered,including Rifadin,have decreased.Which of the following should be done in such a case?

Accepted Answer

Rifampin (Rifadin) is taken orally, undergoes enterohepatic cycling, and induces drug-metabolizing enzymes. This leads to a decrease in the duration of action of both itself and other drugs and may require an increase in drug dosage.

Question 11

Which of the following statements is true about cephalosporins and penicillins?

Accepted Answer

The cephalosporins are bactericidal antibiotics that have chemical structures similar to those of the penicillins. The mechanism of action of the cephalosporins is the same as that of the penicillins. The cephalosporins are usually more resistant than the penicillins to the bacterial beta-lactamase enzymes. They are used as substitutes for penicillins in cases of allergy or bacterial resistance and in the treatment of certain gram-negative infections.

Question 12

Identify the individual who should receive chemoprophylaxis.

Accepted Answer

Chemoprophylaxis refers to the use of antibiotics before bacterial infection has developed in order to prevent infection. Individuals who have had rheumatic fever, heart valve replacement, knee and hip replacement, and other conditions are particularly susceptible to infections that can cause endocarditis and heart valve damage. These individuals should receive chemoprophylaxis before dental, respiratory, urinary, and other invasive medical procedures.

Question 13

Which of the following statements is true of the tetracyclines?

Accepted Answer

The tetracyclines are broad-spectrum antibiotics that are actively taken up by bacteria. The tetracyclines are bacteriostatic; they bind reversibly to bacterial ribosomes to inhibit bacterial protein synthesis. The tetracyclines affect both gram-positive and gram-negative bacteria.

Question 14

Which of the following drugs is generally preferred for complicated urinary tract infections caused by gram-negative species of Klebsiella?

Accepted Answer

Complicated infections are usually caused by gram-negative species of Klebsiella and Pseudomonas. Fluoroquinolones (7-10 days) such as ciprofloxacin and levofloxacin are generally preferred.

Question 15

Which of the following statements is true about the treatment of vancomycin-resistant infections?

Accepted Answer

Daptomycin (Cubicin) is indicated for treatment of vancomycin-resistant skin infections. The drug is bactericidal and believed to damage the bacterial cell membrane.

Quiz 41: End of Chapter Questions