Abx - Pharmacology II
A hospitalized AIDS patient is receiving antiretroviral drugs but no antimicrobial prophylaxis. He develops sepsis with fever, suspected to be caused by a gram-negative bacillus. Antimicrobial treatment of this severely immune-depressed patient should not be initiated before (A) Antipyretic drugs have been given to reduce body temperature (B) Infecting organism(s) have been identified by the microbiology laboratory (C) Results of a Gram stain are available (D) Results of antibacterial susceptibility tests are available (E) Specimens have been taken for laboratory tests and examination
(E) Specimens have been taken for laboratory tests and examination
More than 90% of this drug is excreted in the urine in intact form. Because its urinary solubility is low, patients should be well hydrated to prevent nephrotoxicity. Which drug is described? (A) Acyclovir (B) Efavirenz (C) Indinavir (D) Trifluridine (E) Zidovudine
(A) Acyclovir
Which statement about fluconazole is accurate? (A) Does not penetrate the blood-brain barrier (B) Drug of choice in treatment of aspergillosis (C) Induces hepatic drug-metabolizing enzymes (D) Has the least effect of all azoles on drug metabolism (E) Oral bioavailability is less than that of ketoconazole
(D) Has the least effect of all azoles on drug metabolism
A 33-year-old man was seen in a clinic with a complaint of dysuria and urethral discharge of yellow pus. He had a painless clean-based ulcer on the penis and nontender enlargement of the regional lymph nodes. Gram stain of the urethral exudate showed gram-negative diplococci within polymorphonucleocytes. The patient informed the clinic staff that he was unemployed and had not eaten a meal for 2 d. The most appropriate treatment of gonorrhea in this patient is (A) A single intramuscular dose of ceftriaxone (B) Amoxicillin orally for 7 d (C) Procaine penicillin G intramuscularly as a single dose plus oral probenecid (D) Meropenem orally for 7 d (E) Vancomycin intramuscularly as a single dose
(A) A single intramuscular dose of ceftriaxone
Which statement about vancomycin is accurate? (A) Active against methicillin-resistant staphylococci (B) Bacteriostatic (C) Binds to PBPs (D) Hepatic metabolism (E) Oral bioavailability
(A) Active against methicillin-resistant staphylococci
A 52-year-old man (weight 70 kg) is brought to the hospital emergency department in a confused and delirious state. He has had an elevated temperature for more than 24 h, during which time he had complained of a severe headache and had suffered from nausea and vomiting. Lumbar puncture reveals an elevated opening pressure, and cerebrospinal fluid findings include elevated protein, decreased glucose, and increased neutrophils. Gram stain of a smear of cerebrospinal fluid reveals gram-positive diplococci, and a preliminary diagnosis is made of purulent meningitis. The microbiology report informs you that for approximately 15% of S pneumoniae isolates in the community, the minimal inhibitory concentration for penicillin G is 20 mcg/mL. If this patient had been 82-years-old and the Gram stain of the smear of cerebrospinal fluid had revealed gram-positive rods resembling diphtheroids, the antibiotic regimen for empiric treatment would include (A) Ampicillin (B) Cefoxitin (C) Ceftriaxone (D) Fosfomycin (E) Vancomycin
(A) Ampicillin
A 48-year-old patient is scheduled for a vaginal hysterectomy. An antimicrobial drug will be used for prophylaxis against postoperative infection. It is proposed that cefazolin, a first-generation cephalosporin, be given intravenously at the normal therapeutic dose immediately before surgery and continued until the patient is released from the hospital. Which statement about the proposed drug management of this patient is not accurate? (A) Antibiotic treatment throughout hospitalization will prevent nosocomial infections (B) Likely pathogens include anaerobes, enteric gram-negative bacteria, and group B streptococci (C) Prophylaxis with antimicrobial drugs has efficacy in this type of surgical procedure (D) This drug will not be effective against anaerobes (E) Without prophylaxis, the infection rate following this procedure exceeds 5% under optimal conditions
(A) Antibiotic treatment throughout hospitalization will prevent nosocomial infections
Which parasite is susceptible to niclosamide? (A) Ascaris lumbricoides (roundworm) (B) Echinococcus granulosus (hydatid disease) (C) Fasciola hepatica (sheep liver fluke) (D) Necator americanus (hookworm) (E) Taenia solium (pork tapeworm)
(E) Taenia solium (pork tapeworm)
A 24-year-old woman comes to a clinic with complaints of dry cough, headache, fever, and malaise, which have lasted 3 or 4 d. She appears to have some respiratory difficulty, and chest examination reveals rales but no other obvious signs of pulmonary involvement. However, extensive patchy infiltrates are seen on chest x-ray film. Gram stain of expectorated sputum fails to reveal any bacterial pathogens. The patient mentions that a colleague at work had similar symptoms to those she is experiencing. The patient has no history of serious medical problems. She takes loratadine for allergies and supplementary iron tablets, and she drinks at least 6 cups of caffeinated coffee per day. The physician makes an initial diagnosis of community-acquired pneumonia. A 5-d course of treatment for community-acquired pneumonia would be effective in this patient with little risk of drug interactions if the drug prescribed were (A) Azithromycin (B) Clindamycin (C) Doxycycline (D) Erythromycin (E) Vancomycin
(A) Azithromycin
Your 23-year-old female patient is pregnant and has gonorrhea. The medical history includes anaphylaxis following exposure to amoxicillin. The most appropriate drug to use is (A) Azithromycin (B) Cefixime (C) Ceftriaxone (D) Ciprofloxacin (E) Doxycycline
(A) Azithromycin
A 36-year-old woman recently treated for leukemia is admitted to the hospital with malaise, chills, and high fever. Gram stain of blood reveals the presence of gram-negative bacilli. The initial diagnosis is bacteremia, and parenteral antibiotics are indicated. The records of the patient reveal that she had a severe urticarial rash, hypotension, and respiratory difficulty after oral penicillin V about 6 mo ago. The most appropriate drug regimen for empiric treatment is (A) Aztreonam (B) Ceftriaxone (C) Meropenem (D) Oxacillin (E) Ticarcillin plus clavulanic acid
(A) Aztreonam
A traveler in a geographical region where chloroquine-resistant P falciparum is endemic used a drug for prophylaxis but nevertheless developed a severe attack of P vivax malaria. Which drug should be used for oral treatment of the acute attack of P vivax malaria but does not eradicate exoerythrocytic forms of the parasite? (A) Chloroquine (B) Mefloquine (C) Primaquine (D) Pyrimethamine-sulfadoxine (E) Quinidine
(A) Chloroquine
The primary reason for the use of drug combinations in the treatment of tuberculosis is to (A) Delay or prevent the emergence of resistance (B) Ensure patient compliance with the drug regimen (C) Increase antibacterial activity synergistically (D) Provide prophylaxis against other bacterial infections (E) Reduce the incidence of adverse effects
(A) Delay or prevent the emergence of resistance
Which statement about "once-daily" dosing with aminoglycosides is not accurate? (A) Dose adjustment is less important in renal dysfunction (B) It is convenient for outpatient treatment (C) Less nursing time is required for drug administration (D) Often less side effects than multiple (conventional) dosing regimens (E) Underdosing is less of a problem
(A) Dose adjustment is less important in renal dysfunction
Concerning quinupristin-dalfopristin, which statement is accurate? (A) Active in treatment of infections caused by E faecalis (B) An effective drug in treatment of multidrug-resistant streptococcal infections (C) Bacteriostatic (D) Hepatotoxicity has led to FDA drug alerts (E) Increase the activity of hepatic drug-metabolizing enzymes
(B) An effective drug in treatment of multidrug-resistant streptococcal infections
All of the following statements about the clinical uses of the aminoglycosides are accurate except (A) Effective in the treatment of infections caused by anaerobes such as Bacteroides fragilis (B) Gentamycin is used with ampicillin for synergistic effects in the treatment of enterococcal endocarditis (C) In the treatment of a hospital-acquired infection caused by Serratia marcescens, netilmicin is more effective than streptomycin (D) Often used with cephalosporins in the empiric treatment of life-threatening bacterial infections (E) Owing to their polar nature, aminoglycosides are not absorbed after oral administration
(A) Effective in the treatment of infections caused by anaerobes such as Bacteroides fragilis
A student studying medicine at a Caribbean university develops intestinal bilharziasis and oxamniquine is prescribed. Which statement about the proposed drug therapy is accurate? (A) Hospitalization is recommended if the patient has a history of seizure disorders (B) Oxamniquine is not effective in the late stages of the disease (C) Oxamniquine is safe to use in pregnancy (D) The drug is an antagonist at GABA receptors in trematodes (E) The drug is very effective in tapeworm infections
(A) Hospitalization is recommended if the patient has a history of seizure disorders
A 21-year-old woman from Southeast Asia has been staying with family members in the United States for the last 3 mo and is looking after her sister's preschool children during the day. Because she has difficulty with the English language, her sister escorts her to the emergency department of a local hospital. She tells the staff that her sister has been feeling very tired for the last month, has a poor appetite, and has lost weight. The patient has been feeling somewhat better lately except for a cough that produces a greenish sputum, sometimes specked with blood. With the exception of rales in the left upper lobe, the physical examination is unremarkable and she does not seem to be acutely ill. Laboratory values show a white count of 12,000/μL and a hematocrit of 33%. Chest x-ray film reveals an infiltrate in the left upper lobe with a possible cavity. A Gram-stained smear of the sputum shows mixed flora with no dominance. An acid-fast stain reveals many thin rods of pinkish hue. A preliminary diagnosis is made of pulmonary tuberculosis. Sputum is sent to the laboratory for culture. At this point, the most appropriate course of action is to (A) Hospitalize the patient and start treatment with 4 antitubercular drugs (B) Hospitalize the patient and start treatment with rifampin (C) Prescribe isoniazid for prophylaxis and send the patient home to await culture results (D) Provide no drugs and send the patient home to await culture results (E) Treat the patient with isoniazid plus rifampin
(A) Hospitalize the patient and start treatment with 4 antitubercular drugs
Which helminthic infection does not respond to treatment with praziquantel? (A) Hydatid disease (B) Opisthorchiasis (C) Paragonimiasis (D) Pork tapeworm infection (E) Schistosomiasis
(A) Hydatid disease
If ampicillin and piperacillin are used in combination in the treatment of infections resulting from Pseudomonas aeruginosa, antagonism may occur. The most likely explanation is that (A) Ampicillin is bacteriostatic (B) Ampicillin induces beta-lactamase production (C) Autolytic enzymes are inhibited by piperacillin (D) Piperacillin blocks the attachment of ampicillin to penicillin-binding proteins (E) The 2 drugs form an insoluble complex
(B) Ampicillin induces beta-lactamase production
A 27-year-old pregnant patient with a history of pyelonephritis has developed a severe upper respiratory tract infection that appears to be due to a bacterial pathogen. The woman is hospitalized, and an antibacterial agent is to be selected for treatment. Which antibacterial agent appears to be the safest to use in the pregnant patient? (A) Amikacin (B) Azithromycin (C) Ciprofloxacin (D) Erythromycin (E) Tetracycline
(B) Azithromycin
Once-weekly administration of which of the following antibiotics has prophylactic activity against bacteremia caused by M avium complex in AIDS patients? (A) Acedapsone (B) Azithromycin (C) Clarithromycin (D) Kanamycin (E) Rifabutin
(B) Azithromycin
A 27-year-old pregnant patient with a history of pyelonephritis has developed a severe upper respiratory tract infection that appears to be due to a bacterial pathogen. The woman is hospitalized, and an antibacterial agent is to be selected for treatment. Assuming that the physician is concerned about the effects of renal impairment on drug dosage in this patient, which drug would not require dosage modification in renal dysfunction? (A) Amoxicillin (B) Cefoperazone (C) Ciprofloxacin (D) Trimethoprim-sulfamethoxazole (E) Vancomycin
(B) Cefoperazone
A patient with AIDS has a CD4 count of 45/μL. He is being maintained on a 3-drug regimen of indinavir, didanosine, and zidovudine. For prophylaxis against opportunistic infections, he is also receiving cidofovir, fluconazole, rifabutin, and trimethoprim-sulfamethoxazole. The drug most likely to suppress herpetic infections and provide prophylaxis against CMV retinitis in this patient is (A) Fluconazole (B) Cidofovir (C) Indinavir (D) Rifabutin (E) Trimethoprim-sulfamethoxazole
(B) Cidofovir
A 55-year-old patient with a prosthetic heart valve is to undergo a periodontal procedure involving scaling and root planing. Several years ago, the patient had a severe allergic reaction to procaine penicillin G. Regarding prophylaxis against bacterial endocarditis, which one of the following drugs taken orally is most appropriate? (A) Amoxicillin 10 min before the procedure (B) Clindamycin 1 h before the procedure (C) Erythromycin 1 h before the procedure and 4 h after the procedure (D) Vancomycin 15 min before the procedure (E) No prophylaxis is needed because this patient is in the negligible risk category
(B) Clindamycin 1 h before the procedure
Plasmodial resistance to chloroquine is due to (A) Change in receptor structure (B) Decreased accumulation of the drug in the food vacuole (C) Increased activity of DNA repair mechanisms (D) Increased synthesis of dihydrofolate reductase (E) Induction of drug-inactivating enzymes
(B) Decreased accumulation of the drug in the food vacuole
A 30-year-old male patient who is HIV-positive and symptomatic has a CD4 count of 250/μL and a viral RNA load of 15,000 copies/mL. His treatment involves a 3-drug antiviral regimen consisting of zidovudine, didanosine, and ritonavir. The patient is taking acyclovir for a herpes infection and ketoconazole for oral candidiasis. He now complains of anorexia, nausea and vomiting, and abdominal pain. His abdomen is tender in the epigastric area. Laboratory results reveal an amylase activity of 220 U/L, and a preliminary diagnosis is made of acute pancreatitis. If this patient has acute pancreatitis, the drug most likely to be responsible is (A) Acyclovir (B) Didanosine (C) Ketoconazole (D) Ritonavir (E) Zidovudine
(B) Didanosine
Which drug is least likely to be effective in the treatment of esophageal candidiasis if it is used by the oral route? (A) Clotrimazole (B) Griseofulvin (C) Ketoconazole (D) Itraconazole (E) Nystatin
(B) Griseofulvin
A hospitalized AIDS patient is receiving antiretroviral drugs but no antimicrobial prophylaxis. He develops sepsis with fever, suspected to be caused by a gram-negative bacillus. If amikacin is used in the treatment of this patient, monitoring of serum drug level may be advised because the drug (A) Does not penetrate into cerebrospinal fluid (B) Has a narrow therapeutic window (C) Is antagonized by beta-lactam antibiotics (D) Is hematotoxic (E) Is rapidly metabolized by the liver
(B) Has a narrow therapeutic window
A 21-year-old woman from Southeast Asia has been staying with family members in the United States for the last 3 mo and is looking after her sister's preschool children during the day. Because she has difficulty with the English language, her sister escorts her to the emergency department of a local hospital. She tells the staff that her sister has been feeling very tired for the last month, has a poor appetite, and has lost weight. The patient has been feeling somewhat better lately except for a cough that produces a greenish sputum, sometimes specked with blood. With the exception of rales in the left upper lobe, the physical examination is unremarkable and she does not seem to be acutely ill. Laboratory values show a white count of 12,000/μL and a hematocrit of 33%. Chest x-ray film reveals an infiltrate in the left upper lobe with a possible cavity. A Gram-stained smear of the sputum shows mixed flora with no dominance. An acid-fast stain reveals many thin rods of pinkish hue. A preliminary diagnosis is made of pulmonary tuberculosis. Sputum is sent to the laboratory for culture. Which statement concerning the possible use of isoniazid (INH) in this patient is false? (A) Dyspnea, flushing, palpitations, and sweating may occur after ingestion of tyramine-containing foods (B) In patients from Southeast Asia, lower maintenance doses are necessary (C) Peripheral neuritis may occur during treatment (D) The patient should take pyridoxine daily (E) The risk of the patient developing hepatitis from INH is less than 2%
(B) In patients from Southeast Asia, lower maintenance doses are necessary
This drug can clear trypanosomes from the blood and lymph nodes and is active in the late CNS stages of African sleeping sickness. (A) Emetine (B) Melarsoprol (C) Nifurtimox (D) Pentamidine (E) Suramin
(B) Melarsoprol
A 65-year-old woman has returned from a vacation abroad suffering from traveler's diarrhea, and her problem has not responded to antidiarrheal drugs. A pathogenic gram-negative bacillus is suspected. Which drug is most likely to be effective in the treatment of this patient? (A) Ampicillin (B) Ofloxacin (C) Sulfadiazine (D) Trimethoprim (E) Vancomycin
(B) Ofloxacin
Regarding the toxicity of aminoglycosides which statement is accurate? (A) Gentamicin and tobramycin are the least likely to cause renal damage (B) Ototoxicity due to amikacin and gentamicin includes vestibular dysfunction, which is often irreversible (C) Ototoxicity is reduced if loop diuretics are used to facilitate the renal excretion of aminoglycoside antibiotics (D) Reduced blood creatinine is an early sign of aminoglycoside nephrotoxicity (E) Skin reactions are very rare following topical use of neomycin
(B) Ototoxicity due to amikacin and gentamicin includes vestibular dysfunction, which is often irreversible
Regarding the mechanism of action of aminoglycosides, the drugs (A) Are bacteriostatic (B) Bind to the 50S ribosomal subunit (C) Cause misreading of the code on the mRNA template (D) Inhibit peptidyl transferase (E) Stabilize polysomes
(C) Cause misreading of the code on the mRNA template
A 52-year-old man (weight 70 kg) is brought to the hospital emergency department in a confused and delirious state. He has had an elevated temperature for more than 24 h, during which time he had complained of a severe headache and had suffered from nausea and vomiting. Lumbar puncture reveals an elevated opening pressure, and cerebrospinal fluid findings include elevated protein, decreased glucose, and increased neutrophils. Gram stain of a smear of cerebrospinal fluid reveals gram-positive diplococci, and a preliminary diagnosis is made of purulent meningitis. The microbiology report informs you that for approximately 15% of S pneumoniae isolates in the community, the minimal inhibitory concentration for penicillin G is 20 mcg/mL. Treatment of this patient should be initiated immediately with intravenous administration of (A) Amoxicillin (B) Cephalexin (C) Ceftriaxone plus vancomycin (D) Nafcillin (E) Piperacillin
(C) Ceftriaxone plus vancomycin
A 52-year-old man (weight 70 kg) is brought to the hospital emergency department in a confused and delirious state. He has had an elevated temperature for more than 24 h, during which time he had complained of a severe headache and had suffered from nausea and vomiting. Lumbar puncture reveals an elevated opening pressure, and cerebrospinal fluid findings include elevated protein, decreased glucose, and increased neutrophils. Gram stain of a smear of cerebrospinal fluid reveals gram-positive diplococci, and a preliminary diagnosis is made of purulent meningitis. The microbiology report informs you that for approximately 15% of S pneumoniae isolates in the community, the minimal inhibitory concentration for penicillin G is 20 mcg/mL. Resistance of pneumococci to penicillin G is due to (A) Alterations in porin structure (B) Beta-lactamase production (C) Changes in chemical structure of target penicillin-binding proteins (D) Changes in the d-Ala-d-Ala building block of peptidoglycan precursor (E) Decreased intracellular accumulation of penicillin G
(C) Changes in chemical structure of target penicillin-binding proteins
A 4-year-old child is brought to the hospital after ingesting pills that a parent had used for bacterial dysentery when traveling outside the United States. The child has been vomiting for more than 24 h and has had diarrhea with green stools. She is now lethargic with an ashen color. Other signs and symptoms include hypothermia, hypotension, and abdominal distention. The drug most likely to be the cause of this problem is (A) Ampicillin (B) Azithromycin (C) Chloramphenicol (D) Doxycycline (E) Erythromycin
(C) Chloramphenicol
A 24-year-old woman comes to a clinic with complaints of dry cough, headache, fever, and malaise, which have lasted 3 or 4 d. She appears to have some respiratory difficulty, and chest examination reveals rales but no other obvious signs of pulmonary involvement. However, extensive patchy infiltrates are seen on chest x-ray film. Gram stain of expectorated sputum fails to reveal any bacterial pathogens. The patient mentions that a colleague at work had similar symptoms to those she is experiencing. The patient has no history of serious medical problems. She takes loratadine for allergies and supplementary iron tablets, and she drinks at least 6 cups of caffeinated coffee per day. The physician makes an initial diagnosis of community-acquired pneumonia. If this patient were to be treated with erythromycin, she should (A) Avoid exposure to sunlight (B) Avoid taking supplementary iron tablets (C) Decrease her intake of caffeinated beverages (D) Have her plasma urea nitrogen or creatinine checked before treatment (E) Temporarily stop taking loratadine
(C) Decrease her intake of caffeinated beverages
A 72-kg patient with creatinine clearance of 80 mL/min has a gram-negative infection. Amikacin is administered intramuscularly at a dose of 5 mg/kg every 8 h, and the patient begins to respond. After 2 d, creatinine clearance declines to 40 mL/min. Assuming that no information is available about amikacin plasma levels, what would be the most reasonable approach to management of the patient at this point? (A) Administer 5 mg/kg every 12 h (B) Decrease the dosage to daily total of 200 mg (C) Decrease the dosage to 180 mg every 8 h (D) Discontinue amikacin and switch to gentamicin (E) Maintain the patient on the present dosage and test auditory function
(C) Decrease the dosage to 180 mg every 8 h
A 24-year-old woman comes to a clinic with complaints of dry cough, headache, fever, and malaise, which have lasted 3 or 4 d. She appears to have some respiratory difficulty, and chest examination reveals rales but no other obvious signs of pulmonary involvement. However, extensive patchy infiltrates are seen on chest x-ray film. Gram stain of expectorated sputum fails to reveal any bacterial pathogens. The patient mentions that a colleague at work had similar symptoms to those she is experiencing. The patient has no history of serious medical problems. She takes loratadine for allergies and supplementary iron tablets, and she drinks at least 6 cups of caffeinated coffee per day. The physician makes an initial diagnosis of community-acquired pneumonia. Regarding the treatment of this patient, which of the following drugs is most suitable? (A) Ampicillin (B) Clindamycin (C) Doxycycline (D) Linezolid (E) Vancomycin
(C) Doxycycline
Which statement about the clinical use of sulfonamides is false? (A) Active against C trachomatis and can be used topically for treatment of chlamydial infections of the eye (B) Are not effective as sole agents in the treatment of prostatitis (C) Effective in Rocky Mountain spotted fever (D) In some bacterial strains resistance occurs via increased PABA formation (E) Reduced intracellular uptake is a mechanism of sulfonamide resistance in some bacterial strains
(C) Effective in Rocky Mountain spotted fever
Which statement about pyrantel pamoate is accurate? (A) Acts as an antagonist at GABA receptors (B) Equivalent in efficacy to niclosamide in the treatment of tapeworm infections (C) Eradicates adult worms in the colon but not the eggs (D) Hepatotoxicity is dose-limiting (E) Synergistic with praziquantel in cestode infections
(C) Eradicates adult worms in the colon but not the eggs
A 21-year-old woman from Southeast Asia has been staying with family members in the United States for the last 3 mo and is looking after her sister's preschool children during the day. Because she has difficulty with the English language, her sister escorts her to the emergency department of a local hospital. She tells the staff that her sister has been feeling very tired for the last month, has a poor appetite, and has lost weight. The patient has been feeling somewhat better lately except for a cough that produces a greenish sputum, sometimes specked with blood. With the exception of rales in the left upper lobe, the physical examination is unremarkable and she does not seem to be acutely ill. Laboratory values show a white count of 12,000/μL and a hematocrit of 33%. Chest x-ray film reveals an infiltrate in the left upper lobe with a possible cavity. A Gram-stained smear of the sputum shows mixed flora with no dominance. An acid-fast stain reveals many thin rods of pinkish hue. A preliminary diagnosis is made of pulmonary tuberculosis. Sputum is sent to the laboratory for culture. Which drug regimen should be initiated in this patient when treatment is started? (A) Amikacin, isoniazid, pyrazinamide, streptomycin (B) Ciprofloxacin, cycloserine, isoniazid, PAS (C) Ethambutol, isoniazid, pyrazinamide, rifampin (D) Isoniazid, pyrazinamide, rifampin, streptomycin (E) PAS, pyrazinamide, rifabutin, streptomycin
(C) Ethambutol, isoniazid, pyrazinamide, rifampin
Clarithromycin and erythromycin have very similar spectra of antimicrobial activity. The major advantage of clarithromycin is that it (A) Does not inhibit hepatic drug-metabolizing enzymes (B) Eradicates mycoplasmal infections in a single dose (C) Has greater activity against H pylori (D) Is active against methicillin-resistant strains of staphylococci (E) Is active against strains of streptococci that are resistant to erythromycin
(C) Has greater activity against H pylori
A 10-year-old boy has uncomplicated pulmonary tuberculosis. After initial hospitalization, he is now being treated at home with isoniazid, rifampin, and ethambutol. Which statement about this case is accurate? (A) A baseline test of auditory function test is essential before drug treatment is initiated (B) His mother, who takes care of him, does not need INH prophylaxis (C) His 3-year-old sibling should receive INH prophylaxis (D) Polyarthralgia is a potential adverse effect of the drugs the boy is taking (E) The potential nephrotoxicity of the prescribed drugs warrants periodic assessment of renal function
(C) His 3-year-old sibling should receive INH prophylaxis
Which statement about the mechanisms of action of antiviral drugs is accurate? (A) Acyclovir has no requirement for activation by phosphorylation (B) Ganciclovir inhibits viral DNA polymerase but does not cause chain termination (C) Increased activity of host cell ribonucleases that degrade viral mRNA is one of the actions of interferon-α (D) The initial step in activation of foscarnet in HSV-infected cells is its phosphorylation by thymidine kinase (E) The reverse transcriptase of HIV is 30-50 times more sensitive to inhibition by fosamprenavir than host cell DNA polymerases
(C) Increased activity of host cell ribonucleases that degrade viral mRNA is one of the actions of interferon-α
Metronidazole is not effective in the treatment of (A) Amebiasis (B) Infections due to Bacteroides fragilis (C) Infections due to Pneumocystis jiroveci (D) Pseudomembranous colitis (E) Trichomoniasis
(C) Infections due to Pneumocystis jiroveci
A 33-year-old man was seen in a clinic with a complaint of dysuria and urethral discharge of yellow pus. He had a painless clean-based ulcer on the penis and nontender enlargement of the regional lymph nodes. Gram stain of the urethral exudate showed gram-negative diplococci within polymorphonucleocytes. The patient informed the clinic staff that he was unemployed and had not eaten a meal for 2 d. Immunofluorescent microscopic examination of fluid expressed from the penile chancre of this patient revealed treponemes. Because he appears to be infected with Treponema pallidum, the best course of action would be to (A) Administer a single oral dose of fosfomycin (B) Give no other antibiotics because drug treatment of gonorrhea provides coverage for incubating syphilis (C) Inject intramuscular benzathine penicillin G (D) Treat with oral tetracycline for 7 d (E) Treat with vancomycin
(C) Inject intramuscular benzathine penicillin G
A 28-year-old man living on the East Coast was transferred by his employer to California for several months. On his return, he complains of having influenza-like symptoms with fever and a cough. He also has red, tender nodules on his shins. His physician suspects that these symptoms are due to coccidioidomycosis contracted during his stay in California. Which is the drug of choice if this patient is suffering from persistent lung lesions or disseminated disease caused by Coccidioides immitis? (A) Amphotericin B (B) Flucytosine (C) Itraconazole (D) Micofungin (E) Terbinafine
(C) Itraconazole
A missionary from the United States is sent to work in a geographic region of a Central American country where Onchocerca volvulus is endemic. Infections resulting from this tissue nematode (onchocerciasis) are a cause of "river blindness," because microfilariae migrate through subcutaneous tissues and concentrate in the eyes. Which drug should be used prophylactically to prevent onchocerciasis? (A) Albendazole (B) Diethylcarbamazine (C) Ivermectin (D) Oxamniquine (E) Pyrantel pamoate
(C) Ivermectin
Which drug enhances the actions of GABA in nematodes causing muscle paralysis? (A) Albendazole (B) Diethylcarbamazine (C) Ivermectin (D) Oxamniquine (E) Pyrantel pamoate
(C) Ivermectin
Serious cardiac effects have occurred when this drug was taken by patients using the antihistamines astemizole or terfenadine (A) Amphotericin B (B) Griseofulvin (C) Ketoconazole (D) Terbinafine (E) Voriconazole
(C) Ketoconazole
A malnourished 12-year-old child who lives in a rural area of the southern United States presents with weakness, fever, cough, abdominal pain, and eosinophilia. His mother tells you that she has seen long, thin worms in the child's stools, sometimes with blood. A presumptive diagnosis of ascariasis is confirmed by the presence of the ova of A lumbricoides in the stools. However, microscopy also reveals that the stools contain the eggs of Necator americanus. The drug most likely to be effective in the treatment of this child is (A) Diethylcarbamazine (B) Ivermectin (C) Mebendazole (D) Niclosamide (E) Praziquantel
(C) Mebendazole
A traveler in a geographical region where chloroquine-resistant P falciparum is endemic used a drug for prophylaxis but nevertheless developed a severe attack of P vivax malaria. The drug used for prophylaxis was probably (A) Atovaquone (B) Iodoquinol (C) Mefloquine (D) Proguanil (E) Tetracycline
(C) Mefloquine
A 26-year-old woman was treated for a suspected chlamydial infection at a neighborhood clinic. She was given a prescription for oral doxycycline to be taken for 14 d. Three weeks later, she returned to the clinic with a mucopurulent cervicitis. On questioning she admitted not having the prescription filled. The best course of action at this point would be to (A) Delay drug treatment until the infecting organism is identified (B) Rewrite the original prescription for oral doxycycline (C) Treat her in the clinic with a single oral dose of azithromycin (D) Treat her in the clinic with an intravenous dose of amoxicillin (E) Write a prescription for oral erythromycin for 10 d
(C) Treat her in the clinic with a single oral dose of azithromycin
An adult patient (weight 80 kg) has bacteremia suspected to be due to a gram-negative rod. Tobramycin is to be administered using a once-daily dosing regimen, and the loading dose must be calculated to achieve a peak plasma level of 20 mg/L. Assume that the patient has normal renal function. Pharmacokinetic parameters of tobramycin in this patient are as follows: Vd = 30 L; t1/2 = 3 h; CL = 80 mL/min. What loading dose should be given? (A) 100 mg (B) 200 mg (C) 400 mg (D) 600 mg (E) 800 mg
(D) 600 mg
A 37-year-old woman with leukemia was undergoing chemotherapy with intravenous antineoplastic drugs. During treatment, she developed a systemic infection from an opportunistic pathogen. There was no erythema or edema at the catheter insertion site. A white vaginal discharge was observed. After appropriate specimens were obtained for culture, empiric antibiotic therapy was started with gentamicin, nafcillin, and ticarcillin intravenously. This regimen was maintained for 72 h, during which time the patient's condition did not improve significantly. Her throat was sore, and white plaques had appeared in her pharynx. On day 4, none of the cultures had shown any bacterial growth, but both the blood and urine cultures grew out Candida albicans. If amphotericin B is administered, the patient should be premedicated with (A) Diphenhydramine (B) Ibuprofen (C) Prednisone (D) Any or all of the above (E) None of the above
(D) Any or all of the above
Which statement about the fluoroquinolones is accurate? (A) Antacids increase their oral bioavailability (B) Contraindicated in patients with hepatic dysfunction (C) Fluoroquinolones are drugs of choice in a 6-year-old child with a urinary tract (D) Gonococcal resistance to fluoroquinolones may involve changes in DNA gyrase (E) Modification of moxifloxacin dosage is required in patients when creatinine clearance is less than 50 mL/min
(D) Gonococcal resistance to fluoroquinolones may involve changes in DNA gyrase
The mechanism of antibacterial action of tetracycline involves (A) Antagonism of bacterial translocase activity (B) Binding to a component of the 50S ribosomal subunit (C) Inhibition of DNA-dependent RNA polymerase (D) Interference with binding of aminoacyl-tRNA to bacterial ribosomes (E) Selective inhibition of ribosomal peptidyl transferases
(D) Interference with binding of aminoacyl-tRNA to bacterial ribosomes
A 30-year-old male patient who is HIV-positive and symptomatic has a CD4 count of 250/μL and a viral RNA load of 15,000 copies/mL. His treatment involves a 3-drug antiviral regimen consisting of zidovudine, didanosine, and ritonavir. The patient is taking acyclovir for a herpes infection and ketoconazole for oral candidiasis. He now complains of anorexia, nausea and vomiting, and abdominal pain. His abdomen is tender in the epigastric area. Laboratory results reveal an amylase activity of 220 U/L, and a preliminary diagnosis is made of acute pancreatitis. In the further treatment of this patient, the drug causing the pancreatitis should be withdrawn and replaced by (A) Atazanavir (B) Cidofovir (C) Foscarnet (D) Lamivudine (E) Ribavirin
(D) Lamivudine
Which of the following statements about interferon-α is false? (A) At the start of treatment, most patients experience flu-like symptoms (B) Indications include treatment of genital warts (C) It is used in the management of hepatitis B and C (D) Lamivudine interferes with its activity against hepatitis B (E) Toxicity includes bone marrow suppression
(D) Lamivudine interferes with its activity against hepatitis B
A male patient presents with lower abdominal discomfort, flatulence, and occasional diarrhea. A diagnosis of intestinal amebiasis is made, and E histolytica is identified in his diarrheal stools. An oral drug is prescribed, which reduces his intestinal symptoms. Later he presents with severe dysentery, right upper quadrant pain, weight loss, fever, and an enlarged liver. Amebic liver abscess is diagnosed, and the patient is hospitalized. He has a recent history of drug treatment for a cardiac arrhythmia. The preferred treatment that he should have received for the initial symptoms (which were indicative of mild-to moderate disease) is (A) Diloxanide furoate (B) Iodoquinol (C) Metronidazole (D) Metronidazole plus diloxanide furoate (E) Paromomycin
(D) Metronidazole plus diloxanide furoate
The primary mechanism of antibacterial action of the penicillins involves inhibition of (A) Beta-lactamases (B) Cell membrane synthesis (C) N-acetylmuramic acid synthesis (D) Peptidoglycan cross-linking (E) Transglycosylation
(D) Peptidoglycan cross-linking
A 22-year-old man from South Korea has recently moved to Minnesota. He has symptoms of clonorchiasis (anorexia, upper abdominal pain, eosinophilia), presumably contracted in his homeland where the Oriental liver fluke is endemic. He also has symptoms of diphyllobothriasis (abdominal discomfort, diarrhea, megaloblastic anemia), probably caused by consumption of raw fish from lakes near the Canadian border. Which drug is most likely to be effective in the treatment of both clonorchiasis and diphyllobothriasis in this patient? (A) Albendazole (B) Ivermectin (C) Niclosamide (D) Praziquantel (E) Pyrantel pamoate
(D) Praziquantel
A traveler in a geographical region where chloroquine-resistant P falciparum is endemic used a drug for prophylaxis but nevertheless developed a severe attack of P vivax malaria. Which drug should be given later to eradicate schizonts and latent hypnozoites in the patient's liver? (A) Artesunate (B) Dapsone (C) Halofantrine (D) Primaquine (E) Quinine
(D) Primaquine
Which of the following statements about beta-lactam antibiotics is false? (A) Cephalexin and other first-generation cephalosporins do not cross the blood-brain barrier (B) Ceftriaxone and nafcillin are both eliminated mainly via biliary secretion (C) Instability of penicillins in gastric acid can limit their oral absorption (D) Renal tubular reabsorption of amoxicillin is inhibited by probenecid (E) Ticarcillin has activity against several gram negative rods
(D) Renal tubular reabsorption of amoxicillin is inhibited by probenecid
A patient with AIDS has a CD4 count of 45/μL. He is being maintained on a 3-drug regimen of indinavir, didanosine, and zidovudine. For prophylaxis against opportunistic infections, he is also receiving cidofovir, fluconazole, rifabutin, and trimethoprim-sulfamethoxazole. The dose of indinavir in this patient may need to be increased above normal. This is because (A) Fluconazole slows gastric emptying (B) Ganciclovir increases the renal clearance of indinavir (C) Gastric absorption is inhibited by fluconazole (D) Rifabutin increases hepatic drug metabolism (E) Sulfamethoxazole increases indinavir plasma protein binding
(D) Rifabutin increases hepatic drug metabolism
Which drug increases the hepatic metabolism of other drugs? (A) Clarithromycin (B) Erythromycin (C) Ketoconazole (D) Rifampin (E) Ritonavir
(D) Rifampin
A patient with AIDS and a CD4 cell count of 100/μL has persistent fever and weight loss associated with invasive pulmonary disease due to M avium complex (MAC). Optimal management of this patient is to (A) Choose an antibiotic based on drug susceptibility of the cultured organism (B) Initiate a two-drug regimen of INH and pyrazinamide (C) Prescribe rifabutin because it prevents the development of MAC bacteremia (D) Start treatment with the combination of azithromycin, ethambutol, and rifabutin (E) Treat with trimethoprim-sulfamethoxazole
(D) Start treatment with the combination of azithromycin, ethambutol, and rifabutin
A 37-year-old woman with leukemia was undergoing chemotherapy with intravenous antineoplastic drugs. During treatment, she developed a systemic infection from an opportunistic pathogen. There was no erythema or edema at the catheter insertion site. A white vaginal discharge was observed. After appropriate specimens were obtained for culture, empiric antibiotic therapy was started with gentamicin, nafcillin, and ticarcillin intravenously. This regimen was maintained for 72 h, during which time the patient's condition did not improve significantly. Her throat was sore, and white plaques had appeared in her pharynx. On day 4, none of the cultures had shown any bacterial growth, but both the blood and urine cultures grew out Candida albicans. At this point, the best course of action is to (A) Continue current antibiotics and start griseofulvin (B) Continue current antibiotics and start amphotericin B (C) Stop current antibiotics and start itraconazole (D) Stop current antibiotics and start amphotericin B (E) Stop current antibiotics and start terbinafine
(D) Stop current antibiotics and start amphotericin B
Which drug is effective in the treatment of nocardiosis and, in combination with pyrimethamine, is prophylactic against Pneumocystis jirovecii infections in AIDS patients? (A) Amoxicillin (B) Erythromycin (C) Levofloxacin (D) Sulfadiazine (E) Trimethoprim
(D) Sulfadiazine
A 40-year-old man complains of periodic bouts of diarrhea with lower abdominal cramping and intermittent rectal bleeding. Seen in the clinic, he appears well nourished, with blood pressure in the normal range. Examination reveals moderate abdominal pain and tenderness. His current medications are limited to loperamide for his diarrhea. Sigmoidoscopy reveals mucosal edema, friability, and some pus. Laboratory findings include mild anemia and decreased serum albumin. Microbiologic examination via stool cultures and mucosal biopsies do not reveal any evidence for bacterial, amebic, or cytomegalovirus involvement. The most appropriate drug to use in this patient is (A) Ampicillin (B) Doxycycline (C) Norfloxacin (D) Sulfasalazine (E) Trimethoprim-sulfamethoxazole
(D) Sulfasalazine
A nonindigenous person who develops onchocerciasis in an endemic region and receives drug treatment is likely to experience a severe reaction. Symptoms include headache, weakness, rash, muscle aches, hypotension, and peripheral edema. Which statement concerning this reaction is accurate? (A) Extensive fluid replacement is essential (B) Symptoms are more intense in indigenous adults than nonindigenous adults (C) The reaction is due to treatment with suramin (D) The reaction is due to killing of microfilariae (E) The symptoms are characteristic of treatment with diethylcarbamazine
(D) The reaction is due to killing of microfilariae
Regarding the clinical use of liposomal formulations of amphotericin B, which statement is accurate? (A) Amphotericin B affinity for these lipids is greater than affinity for ergosterol (B) Less expensive to use than conventional amphotericin B (C) More effective in fungal infections because they increase tissue uptake of amphotericin B (D) They decrease the nephrotoxicity of amphotericin B (E) They have a wider spectrum of antifungal activity than conventional formulations of amphotericin B
(D) They decrease the nephrotoxicity of amphotericin B
After a backpacking trip in the mountains, a 24-year-old man develops diarrhea. He acknowledges drinking stream water without purification, and you suspect he is showing symptoms of giardiasis. Because you know that laboratory detection of cysts or trophozoites in the feces can be difficult, you decide to treat the patient empirically with (A) Chloroquine (B) Emetine (C) Pentamidine (D) Tinidazole (E) TMP-SMZ
(D) Tinidazole
Trimethoprim-sulfamethoxazole is established to be effective against which of the following opportunistic infections in the AIDS patient? (A) Cryptococcal meningitis (B) Herpes simplex (C) Oral candidiasis (D) Toxoplasmosis (E) Tuberculosis
(D) Toxoplasmosis
A hospitalized AIDS patient is receiving antiretroviral drugs but no antimicrobial prophylaxis. He develops sepsis with fever, suspected to be caused by a gram-negative bacillus. A combination of drugs might be given to this patient to provide coverage against multiple organisms or to obtain a synergistic action. Examples of antimicrobial drug synergism established at the clinical level include the treatment of (A) Cryptococcal meningitis with amphotericin B and flucytosine (B) Coliform infections with sulfamethoxazole and trimethoprim (C) Enterococcal infections with rifampin and vancomycin (D) Pseudomonal infections with carbenicillin and gentamicin (E) All of the above
(E) All of the above
Risk factors for multidrug-resistant tuberculosis include (A) A history of treatment of tuberculosis without rifampin (B) Recent immigration from Asia and living in an area of over 4% isoniazid resistance (C) Recent immigration from Latin America (D) Residence in regions where isoniazid resistance is known to exceed 4% (E) All of the above
(E) All of the above
The primary mechanism of resistance of gram-positive organisms to macrolide antibiotics including erythromycin is (A) Changes in the 30S ribosomal subunit (B) Decreased drug permeability of the cytoplasmic membrane (C) Formation of drug-inactivating acetyltransferases (D) Formation of esterases that hydrolyze the lactone ring (E) Methylation of binding sites on the 50S ribosomal subunit
(E) Methylation of binding sites on the 50S ribosomal subunit
A 31-year-old man has gonorrhea. He has no drug allergies, but a few years ago acute hemolysis followed use of an antimalarial drug. The physician is concerned that the patient has an accompanying urethritis caused by C trachomatis, although no cultures or enzyme tests have been performed. Which of the following drugs will be reliably effective against both gonococci and C trachomatis and safe to use in this patient? (A) Cefixime (B) Ciprofloxacin (C) Spectinomycin (D) Sulfamethoxazole-trimethoprim (E) None of the above
(E) None of the above
A 37-year-old woman with leukemia was undergoing chemotherapy with intravenous antineoplastic drugs. During treatment, she developed a systemic infection from an opportunistic pathogen. There was no erythema or edema at the catheter insertion site. A white vaginal discharge was observed. After appropriate specimens were obtained for culture, empiric antibiotic therapy was started with gentamicin, nafcillin, and ticarcillin intravenously. This regimen was maintained for 72 h, during which time the patient's condition did not improve significantly. Her throat was sore, and white plaques had appeared in her pharynx. On day 4, none of the cultures had shown any bacterial growth, but both the blood and urine cultures grew out Candida albicans. Candida is a major cause of nosocomial bloodstream infection. The opportunistic fungal infection in this patient could have been prevented by administration of (A) Caspofungin (B) Flucytosine (C) Nystatin (D) Voriconazole (E) None of the above
(E) None of the above
Which adverse effect occurs with the use of albendazole during intestinal nematode therapy? (A) Cholestatic jaundice (B) Corneal opacities (C) Hirsutism (D) Peripheral neuropathy (E) None of the above
(E) None of the above
A 28-year-old man living on the East Coast was transferred by his employer to California for several months. On his return, he complains of having influenza-like symptoms with fever and a cough. He also has red, tender nodules on his shins. His physician suspects that these symptoms are due to coccidioidomycosis contracted during his stay in California. This patient should be treated immediately with (A) Amphotericin B (B) Caspofungin (C) Ketoconazole (D) Terbinafine (E) None of these drugs
(E) None of these drugs
A 48-year-old patient is scheduled for a vaginal hysterectomy. An antimicrobial drug will be used for prophylaxis against postoperative infection. It is proposed that cefazolin, a first-generation cephalosporin, be given intravenously at the normal therapeutic dose immediately before surgery and continued until the patient is released from the hospital. If the patient had been scheduled for elective colonic surgery, optimal prophylaxis against infection would be achieved by mechanical bowel preparation and the use of (A) Intravenous cefoxitin (B) Intravenous third-generation cephalosporin (C) Oral amoxicillin (D) Oral ciprofloxacin (E) Oral erythromycin and neomycin
(E) Oral erythromycin and neomycin
Which statement about antitubercular drugs is accurate? (A) Antimycobacterial actions of streptomycin involve inhibition of arabinosyltransferases (B) Cross-resistance of M tuberculosis to isoniazid and pyrazinamide is common (C) Ocular toxicity of ethambutol is prevented by thiamine (D) Pyrazinamide treatment should be discontinued immediately if hyperuricemia occurs (E) Resistance to ethambutol involves mutations in the emb gene
(E) Resistance to ethambutol involves mutations in the emb gene
A 21-year-old woman from Southeast Asia has been staying with family members in the United States for the last 3 mo and is looking after her sister's preschool children during the day. Because she has difficulty with the English language, her sister escorts her to the emergency department of a local hospital. She tells the staff that her sister has been feeling very tired for the last month, has a poor appetite, and has lost weight. The patient has been feeling somewhat better lately except for a cough that produces a greenish sputum, sometimes specked with blood. With the exception of rales in the left upper lobe, the physical examination is unremarkable and she does not seem to be acutely ill. Laboratory values show a white count of 12,000/μL and a hematocrit of 33%. Chest x-ray film reveals an infiltrate in the left upper lobe with a possible cavity. A Gram-stained smear of the sputum shows mixed flora with no dominance. An acid-fast stain reveals many thin rods of pinkish hue. A preliminary diagnosis is made of pulmonary tuberculosis. Sputum is sent to the laboratory for culture. On her release from the hospital, the patient is advised not to rely solely on oral contraceptives to prevent pregnancy because they may be less effective while she is being maintained on antimycobacterial drugs. The agent most likely to interfere with the action of oral contraceptives is (A) Amikacin (B) Ethambutol (C) Isoniazid (D) Pyrazinamide (E) Rifampin
(E) Rifampin
Which adverse effect is most common with sulfonamides? (A) Fanconi's aminoaciduria syndrome (B) Hematuria (C) Kernicterus in the newborn (D) Neurologic dysfunction (E) Skin rash
(E) Skin rash
Which statement about ciprofloxacin is accurate? (A) Antagonism occurs if used with dihydrofolate reductase inhibitors (B) Ciprofloxacin is active against MRSA strains of staphylococci (C) Most "first-time" urinary tract infections are resistant to ciprofloxacin (D) Organisms that commonly cause ear infections are highly resistant (E) Tendinitis may occur during treatment
(E) Tendinitis may occur during treatment
Which statement is accurate regarding the antibacterial action of the aminoglycoside amikacin? (A) Antibacterial activity is often reduced by the presence of an inhibitor of cell wall synthesis (B) Antibacterial action is not concentration-dependent (C) Antibacterial action is time-dependent (D) Efficacy is directly proportional to the duration of time that the plasma level is greater than the minimal inhibitory concentration (E) The drug continues to exert antibacterial effects even after plasma levels decrease below detectable levels
(E) The drug continues to exert antibacterial effects even after plasma levels decrease below detectable levels
A 76-year-old man is seen in a hospital emergency department complaining of pain in and behind the right ear. Physical examination shows edema of the external otic canal with purulent exudate and weakness of the muscles on the right side of the face. The patient informs the physician that he is a diabetic. Gram stain of the exudate from the ear shows many polymorphonucleocytes and gram-negative rods, and samples are sent to the microbiology laboratory for culture and drug susceptibility testing. A preliminary diagnosis is made of external otitis. At this point, which of the following is most appropriate? (A) Amikacin should be injected intramuscularly and the patient should be sent home (B) Analgesics should be prescribed, but antibiotics should be withheld pending microbiological results (C) Oral cefaclor should be prescribed together with analgesics, and the patient should be sent home (D) The patient should be hospitalized and treatment started with imipenem-cilastatin (E) The patient should be hospitalized and treatment started with gentamicin plus ticarcillin
(E) The patient should be hospitalized and treatment started with gentamicin plus ticarcillin
A male patient presents with lower abdominal discomfort, flatulence, and occasional diarrhea. A diagnosis of intestinal amebiasis is made, and E histolytica is identified in his diarrheal stools. An oral drug is prescribed, which reduces his intestinal symptoms. Later he presents with severe dysentery, right upper quadrant pain, weight loss, fever, and an enlarged liver. Amebic liver abscess is diagnosed, and the patient is hospitalized. He has a recent history of drug treatment for a cardiac arrhythmia. The drug regimen most likely to be effective in treating severe extraintestinal disease in this patient is (A) Chloroquine (B) Diloxanide furoate plus iodoquinol (C) Emetine plus diloxanide furoate plus chloroquine (D) Pentamidine followed by mefloquine (E) Tinidazole plus diloxanide furoate
(E) Tinidazole plus diloxanide furoate
This drug has characteristics almost identical to those of gentamicin but has much weaker activity in combination with penicillin against enterococci. (A) Amikacin (B) Erythromycin (C) Netilmicin (D) Spectinomycin (E) Tobramycin
(E) Tobramycin
In an accidental needlestick, an unknown quantity of blood from an AIDS patient is injected into a resident physician. The most recent laboratory report on the AIDS patient shows a CD4 count of 20/μL and a viral RNA load of greater than 107 copies/mL. The most appropriate course of action regarding treatment of the resident is to (A) Determine whether HIV transmission has occurred by monitoring the patient's blood (B) Treat with a single high dose of zidovudine (C) Treat with full doses of zidovudine for 4 wk (D) Treat with single doses of zidovudine and indinavir (E) Treat with zidovudine plus lamivudine plus ritonavir for 4 wk
(E) Treat with zidovudine plus lamivudine plus ritonavir for 4 wk
Supplementary folinic acid may prevent anemia in folate-deficient persons who use this drug; it is a weak base achieving tissue levels similar to those in plasma (A) Ciprofloxacin (B) Levofloxacin (C) Linezolid (D) Sulfamethoxazole (E) Trimethoprim
(E) Trimethoprim
Which statement about antiprotozoal drugs is accurate? (A) Chloroquine is an inhibitor of plasmodial dihydrofolate reductase (B) Mefloquine destroys secondary exoerythrocytic schizonts (C) Primaquine is a blood schizonticide and does not affect secondary tissue schizonts (D) Proguanil complexes with double-stranded DNA-blocking replication (E) Trimethoprim-sulfamethoxazole is the drug of choice for Pneumocystis jiroveci pneumonia
(E) Trimethoprim-sulfamethoxazole is the drug of choice for Pneumocystis jiroveci pneumonia
A 27-year-old nursing mother is diagnosed as suffering from genital herpes. She has a history of this viral infection. Previously, she responded to a drug used topically. Apart from her current problem, she is in good health. Which drug to be used orally is most likely to be prescribed at this time? (A) Amantadine (B) Foscarnet (C) Ritonavir (D) Trifluridine (E) Valacyclovir
(E) Valacyclovir
A patient needs antibiotic treatment for native valve, culture-positive infective enterococcal endocarditis. His medical history includes a severe anaphylactic reaction to penicillin G during the last year. The best approach would be treatment with (A) Amoxicillin-clavulanate (B) Aztreonam (C) Ceftriaxone (D) Ticarcillin (E) Vancomycin
(E) Vancomycin
In a patient suffering from pseudomembranous colitis due to C difficile with established hypersensitivity to metronidazole the most likely drug to be of clinical value is (A) Amoxicillin (B) Chloramphenicol (C) Doxycycline (D) Levofloxacin (E) Vancomycin
(E) Vancomycin
Oral formulations of this drug should not be used in a pregnant AIDS patient because they contain propylene glycol. One of the characteristic adverse effects of the drug is hyperpigmentation on the palms of the hands and soles of the feet, especially in African-American patients. (A) Amprenavir (B) Emtricitabine (C) Efavirenz (D) Fosamprenavir (E) Zalcitabine
(E) Zalcitabine
Interactions between this drug and cell membrane components can result in the formation of pores lined by hydrophilic groups present in the drug molecule. (A) Caspofungin (B) Flucytosine (C) Griseofulvin (D) Nystatin (E) Terbinafine
D) Nystatin
