ID Ch 22 Background & Antibacterials

The Gram-stain of a patient's blood culture reveals Gram-positive cocci in chains. Which organism is consistent with this observation? Acinetobacter baumanni Strep. pyogenes H. influenzae Pseudomonas aerginosa Staph aureus

Strep. pyogenes

TM is a 42 year old male who has been started on Biaxin for treatment of pneumonia. Which of the following medications does not pose a drug interaction with the antibiotic treatment? Sucralfate Voriconazole Simvastatin Methadone Amiodarone

Sucralfate Biaxin (as well as clarithromycin) is a strong CYP3A4 inhibitor and is CI with simvastatin (and lovastatin) and can cause increased concentrations of methadone and voriconazole. Macrolides are associated with QT interval prolongation, which would be additive with amiodarone, methadone and voriconazole. Macrolides do not have chelation issues with sucralfate.

Which of the following requires a pregnancy test prior to starting due to the risk for fetal abnormalities? Ceftaroline Vancomycin Fosfomycin Telavancin Azithromycin

Telavancin

MP presents to the urgent care center with a large cellulitis wound on his left lower extremity. The patient has a history of MRSA infection 2 months prior and the practitioner wants to prescribe something orally that covers MRSA. Which of the following medications fit this description? Quinupristin/Dalfopristin Cubicin Tygacil Zyvox Telavancin

Zyvox

Which of the following antimicrobial agents have activity against Bactroides fragilis? Select all that appy Cefepime Meropenem Cefoxitin Ampicillin/sulbactam Metronidazole

all except cefepime

What is the only cephalosporin that covers MRSA?

ceftaroline

JG, a 46 year old male, is found to have vancomycin-resistant E. faecalis (VRE) on his recent blood cultures. Which of the following regimens is the best option for treatment of his VRE infection? Cefazolin Colistimethate Quinupristin-dalfopristin daptomycin vancomycin

daptomycin It is indicated for the treatment of vancomycin-resistant E. faecalis

DH is a 42 year old male being treated with quinpristin/dalfopristin for a complicated VRE and MRSA infection. What are common toxicities of quinupristin/dalfopristin?

infusion rxns, arthralgia/myalgias, hyperbilirubinemia

Levofloxacin and azithromycin share which of the following pk characteristics? Select all that apply Nephrotoxicity Large volume of distribution Low intracellular concentrations Excellent tissue penetration Lipophilic agents

large volume of distribution Excellent tissue penetration Lipophilic agents Drugs like quinolones and macrolides penetrate tissue well (part of the rationale for use in pneumonia, where penetration into lung tissue is needed). These drugs are also active against atypical pathogens, as they work intracellularly, rather than on the cell wall. Beta-lactams and aminoglycosides are examples of hydrophilic drugs.

All PCNs increase the risk of ______ with accumulation?

seizures

What is augmentin first line treatment for?

1. otitis media 2. sinus infxn

All PCNs should be avoided if patient has allergy except in these 2 cases.

1. syphilis while pregnant 2. HIV pts with poor compliance

HW is a 71 y/o male who has been in the intensive care unit for several weeks and is now being treated for pneumonia, with a lower respiratory culture positive for Pseudomonas aerginosa. His weight is 225 pounds and height is 6'0". His current serum creatinine is 2.4 mcg/dL. Based on the culture sensitivities, the medical team decides to start tobramycin at 2.5 mg/kg. They ask the pharmacist to write the order and administer the first dose at 8 am. Which dose of tobramycin should be administered at 8 am? 560 mg 100 mg 410 mg 220 mg 340 mg

220 mg

What dose of gentamicin should be initiated in MV as part of empiric abx regimen (5'9, 209 lb) 80 mg 175 mg 300 mg 160 mg 560 mg

560 mg MV is obese, so his adjusted body weight (approx. 80 kg) should be used for aminoglycoside dosing. The dose used most commonly for extended interval dosing is 7 mg/kg (but may range from 4-7 mg/kg).

A patient is receiving Bactrim DS therapy. Which of the following strengths and ingredients are in Bactrim DS tablets?

800 mg sulfamethoxazole and 160 mg trimethoprim

MB is a 51 year-old female who has been prescribed Biaxin for pneumonia. She had a heart attack two years ago. During the hospitalization she was found to have an arrhythmia (atrial fibrillation) and was placed on warfarin. Her other medications include simvastatin, atenolol and one fish oil, taken twice daily. Which of the following statements are correct? (Select ALL that apply.) A: Biaxin causes QT prolongation and is not a safe choice in a patient with an existing arrhythmia. B: Biaxin can cause hepatotoxicity. C: Biaxin will increase the levels of simvastatin and may cause muscle damage. D: Biaxin can increase the levels of atenolol and may cause bradycardia. E: Biaxin can increase the levels of fish oils and increase the bleeding risk.

A: Biaxin causes QT prolongation and is not a safe choice in a patient with an existing arrhythmia. B: Biaxin can cause hepatotoxicity. C: Biaxin will increase the levels of simvastatin and may cause muscle damage.

Which of the following groups of pathogens best represents clindamycin's spectrum of activity? Atypical and anaerobic pathogens Aerobic (Streptococci, Staphylococci) and anaerobic Gram-positive pathogens Multidrug-resistant Gram-negative pathogens (Acinetobacter, Pseudomonas) and skin flora (Streptococci, Staphylococci) Enteric Gram-negative pathogens and anaerobic pathogens Parasitic and fungal pathogens

Aerobic (Streptococci, Staphylococci) and anaerobic Gram-positive pathogens Clindamycin has excellent coverage for Gram-positive pathogens (Streptococci, Staphylococci, but not enterococci) and anaerobic pathogens

A patient gave the pharmacist a Rx for Augmentin 875 mg Q12H #20. Which of the following should be dispensed? Ampicillin/tazobactam Ampicillin/clavulanate Amoxicillin/clavulanate Amoxicillin/tazobactam Imipenem/cilistatin

Amoxicillin/clavulanate

LJ is receiving ampicillin/sulbactam for the treatmetn of a Proteus mirabilis bacteremia. The physcian wants to know how ampicillin/sulbactam works. Which of the following best characterizes the pharmacodynamic properties of ampicillin/sulbactam. Ampicillin/sulbactam exhibits AUC:MIC killing Ampicillin/sulbactam exhibits time-dependent bacterial killing Ampicillin/sulbactam exhibits post antibiotic effect for bacterial killing Ampicillin/sulbactam exhibits concentration-dependent bacterial killing Ampicillin/sulbactam exhibits concentration-above-MIC-dependent killing

Ampicillin/sulbactam exhibits time-dependent bacterial killing

A patient gave the pharmacist a prescription for Z-pak. Which of the following is the generic name and an appropriate dosing regimen for Z-pak? Clarithromycin 250 mg Q AM, for 5 days Azithromycin 250 mg Q x2, for 5 days Erythromycin 250 mg Q AM, for 5 days Azithromycin 250 mg x 1, for 5 days Azithromycin 250 x 2 on day 1, then 20 mg x 1 on day 2-5

Azithromycin 250 x 2 on day 1, then 250 mg x 1 on day 2-5

A patient gave the pharmacist a prescription for ceftin 500 mg BID #14. Which of the following is an appropriate generic substitution for Ceftin? Cefprozil Doripenem Cefdinir Cefuroxime Cefpodoxime

Cefuroxime

An otherwise healthy patient presents with a foot infection that developed 1 week after stepping on a child's toy. The wound is growing Gram-positive and Gram-negative bacteria; Pseudomonas is not suspected. The physician would like to use a cephalosporin for treatment of the patients infection. Which of the following statements regarding cephalosporins is correct? Cefiximine is the only oral cephalosporin with Gram-negative and enteric anaerobic coverage. Cefuroximine is an oral, second-generation cephalosporin with adequate Gram-negative and Gram-positive coverage for mild-moderate foot infections. Cefpodoxime is an intravenous, third-generation cephalosporin with adequate Gram-positive and Gram-negative coverage for severe foot infections. Cefazolin is an oral cephalosporin that is considered to be the most effective therapy for mild-moderate Gram-negative foot infections. Cephalexin is an oral, second-generation cephalosporin with sufficient Gram-negative and Gram-positive coverage for moderate severity foot infections.

Cefuroximine is an oral, second-generation cephalosporin with adequate Gram-negative and Gram-positive coverage for mild-moderate foot infections.

Atypical bacteria do not stain well name them

Chlamydia Legionella Mycoplasma pneumoniae Mycobacterium tuberculosis

A patient has been taking antibiotics for one week and develops severe diarrhea with painful abdominal cramps. Which of the following medications has a boxed warning regarding the risk of causing severe and possibly fatal colitis? Cefepime Biaxin Cancidas Clindmycin Cipro

Clindamycin Although clindamycin carries a boxed warning for risk of severe and possibly fatal colitis, all antibiotics carry a warning for risk of superinfections including risk of C. difficile-associated diarrhea. When counseling, tell patients to report watery and/or frequent diarrhea immediately as the patient may require treatment for pseudomembranous colitis

JR has been in the intensive care unit for the past two weeks. He was initially admitted for an asthma exacerbation requiring mechanical ventilation. Over the course of the hospitalization, he developed ventilator-associated pneumonia and was treated with broad spectrum antibiotics. His blood cultures are now positive for E. faecium which is vancomycin-resistance (VRE). Which of the following antibiotics provide coverage for vancomycin-resistant E. faecium bacteremia? Invanz Cubicin Vancocin Avelox MacroBID

Cubicin

As a class Cephalosporins are not effective against?

Enterococcus species

JP has a blood culture report showing Gram-positive cocci resembling Streptococci, enteric Gram-negative rods and anaerobes. Which of the following medications would provide adequate coverage for these organisms? Ertapenem Fosfomycin Ciprofloxacin Metronidazole Rifaximin

Ertapenem Carbapenem are very broad-spectrum antibiotics. They cover gram positives, gram negatives and anaerobes. Rifaximin, metronidazole and fosfomycin have a much narrower spectrum. Ciprofloxacin does not have reliable strep coverage, nor does it cover anaerobes.

BJ is on tobramycin IV every 8 hours for treating a gram-negative infection and his levels are reported as a peak of 8.3 mcg/mL and a trough of 2.5 mcg/mL. Which of the following recommendations should the pharmacist make to the medical team? Increase the dose of tobramycin Continue the current regimen Extend the dosing interval of tobramycin Shorten the dosing interval of tobramycin Decrease the dose of tobramycin

Extend the dosing interval of tobramycin The peak of tobramycin is within range, but the trough level is above the goal level (it should be less than 2 mcg/mL and ideally less than 1.5 mcg/mL). By extending the dosing interval, the trough level will decrease and the toxicity risk is lowered without decreasing the peak for this concentration-dependent drug.

1st gen cephalosporins have excellent coverage against?

Gram positive cocci (Streptococci and Staphylococi)

SN is prescribed Avelox for a community-acquired pneumonia infection. What is the mechanism of action for Avelox? Binds to the 50s ribosomal subunit, inhibiting synthesis inhibit synthesis of Beta (1,3)-D-glucan Binds to the 30s ribosomal subunit, inhibiting protein synthesis Binds to penicillin binding proteins to inhibit cell wall synthesis Inhibits DNA topoisomerase IV, thereby blocking DNA gyrase

Inhibits DNA topoisomerase IV, thereby blocking DNA gyrase

Which of the following statements are correct regarding use of Bactrim for toxoplasmosis prophylaxis? Select All that apply It can increase the risk of sunburn It should be taken with 8 oz of water It should not be use if the patient has a sulfa allergy It can cause a serious rash requiring immediate medical attention It should not be used for toxoplasmosis prophylaxis

It can increase the risk of sunburn It should be taken with 8 oz of water It should not be use if the patient has a sulfa allergy It can cause a serious rash requiring immediate medical attention

Which of the following statements are correct with regard to sulfamethoxazole/trimethoprim? Select all that apply It is potent hepatic enzyme inducer resulting in reduced drug concentrations It has excellent bioavailability, thus can transition form intravenous to oral formulations in a 1:1 fashion A negative Coombs test with sulfamethoxazole/trimethoprim indicates hemolytic anemia It should be avoided in a patient with a G6PD deficiency It is active against Gram-positive pathogens, including Staphylococci, Gram-negative pathogens and opportunistic pathogens.

It has excellent bioavailability, thus can transition form intravenous to oral formulations in a 1:1 fashion It should be avoided in a patient with a G6PD deficiency It is active against Gram-positive pathogens, including Staphylococci, Gram-negative pathogens and opportunistic pathogens. TMP/SMX is a potent CYP2C9 inhibitor (not inducer). It has 1:1 conversion form IV:PO dosing. It is a broad spectrum agent with excellent Gram-positive, Gram-negative (not Pseudomonas) and opportunistic pathogen coverage. It is partially cleared by the kidney and should be dosed reduced for CrCl < 30 mL/min. A positive Coombs test in the labs (along with decreasing hemoglobin/hemocrit) would indicate the presence of hemolytic anemia and Bactrim should be discontinued.

Which of the following statements are true regarding Zyvox? Select all that apply It is cleared primarily by the kidney requiring dose adjustments in the setting of renal impairment It has excellent bioavailability, thus can transition form intravenous to oral formulations in a 1:1 fashion There is a risk for serotonin syndrome if used with SSRI antidepressants Myelosuppression can occur with use of Zyvox Nephrotoxicity is a common toxicity with prolonged use

It has excellent bioavailability, thus can transition form intravenous to oral formulations in a 1:1 fashion There is a risk for serotonin syndrome if used with SSRI antidepressants Myelosuppression can occur with use of Zyvox

Which of the following beta-lactam antibiotics can be given by mouth? PCN G benzthine Keflex Augmentin Ceftriaxone Cefdinir Zosyn Cefazolin

Keflex Augmentin Cefdinir

Common resistant pathogens: Kill Each And Every Strong Pathogens

Klebsiella pneumoniae Escherichia coli Acinetobacter baumanni Enterococcus faecalis Staphylococcus aureus Pseudomonas aeruginosa

Clindamycin (MIC > 16) - R Erythromycin (MIC > 4) - R Oxacillin (MIC > 2) - R Linezolid (MIC = 2) - S Tetracycline (MIC < = 0.5) - S Sulfamethoxazole/ Trimethoprim (MIC <= 0.5/9.5) - S Vancomycin (MIC = 2) - S Which ABX would you recommend?

Linezolid When the vancomycin MIC is >= 2, alternative ABX should be considered. Daptomycin and dalbavancin are not indicated for pneumonia and sulfamethoxazole/trimethoprim should not be used in a patient with a sulfa allergy.

Which of the following statements is correct regarding linezolid? Linezolid is a strong CYP1A2 inhibitor Linezolid is associated with hemolytic anemia in patients with G6PD Linezolid should be dose adjusted in renal impairment Linezolid covers MRSA but not VRE Linezolid is associated with bone marrow suppression

Linezolid is associated with bone marrow suppression

RF is a 58 year old male who is in the medical intensive care unit with a severe Pseudomonas aerginosa lung infection. He is on ciprofloxacin and cefepime and his infection does not seem to be clearing. Which of the following medications could be used to cover the same pathogen in place of the current therapy? Zyvox Tygacil Invanz Meropenem Minocycline

Meropenem All the carbapenems, except Invanz, cover Pseudomonas aerginosa, but perhaps this infection is resistant.

NA is a 42 year old female who was a victim of a house fire. She acquired third degree burns requiring skin grafting. Unfortunately her course has been complicated by post-operative Acinetobacter wound infection and acute kidney injury. She has no known drug allergies. Which of the following antibacterials would be considered first line in her case as a single agent? Meropenem Fosfomycin Vancomycin Ampicillin Linezolid

Meropenem It is drug of choice for treating Acinetobacter

Choose the correct term for the lowest drug concentration that will inhibit the growth of an organism: Trough concentration Post-antibiotic effect Intermediate sensitivity Resistance threshold Minimum inhibitory concentration

Minimum inhibitory concentration

Which of the following medications should be avoided in children younger than 8 years old due to discoloration of teeth and bone growth retardation? Telavancin Telithromycin Tindazole Minocycline Rifaximin

Minocycline

Which two antibiotics should be separated from multivitamin supplements? Avelox and amoxicillin Biaxin and Zyvox Minocycline and Levofloxacin Bactrim and Zithromax Flagyl and cefuroxime

Minocycline and Levofloxacin

Which of the following statements is correct regarding nafcillin? Nafcillin cannot be used in a sulf allergic patient Nafcillin is a vesicant Nafcillin is active against MRSA Nafcillin is compatible with NS only Nafcillin should be dose adjusted in renal impairment

Nafcillin is a vesicant

Which of the following can interfere with coagulation laboratory assays? Select all that apply Bactrim Linezolid Oritavancin Telavancin Daptomycin

Oritavancin Telavancin Daptomycin

What is the only PCN used against pseudomonas?

Piperacillin/Tazobactam

A hospitalized patient with no known drug allergies has cellulitis and the physician ordered vancomycin 1000 mg IV Q12H and imipenem-cilastatin 1000mg IV Q8H. The medication were administered at the same time over 30 minutes. During the infusion, the patient experienced a profound drop in blood pressure. Her upper body, mostly in the trunk area, was covered with an erythematous rash. The patient's breathing became labored. What is the likely cause of the patient's symptoms? The reaction was due to the combination of imipenem-cilastatin and vancomycin; the administration should be separated by several hours These are side effects of the cilastatin component, which has not been reduced for renal insufficiency. Rapid administration of vancomycin caused red man syndrome It is unlikely that this reaction is due to one of these medications She likely had an anaphylactic reaction to cilastatin

Rapid administration of vancomycin caused red man syndrome

A patient has an MRSA wound infection. She has heart failure and impaired renal function with an estimated creatinine clearance of 40 mL/min. Her current medications include Toprol XL, Zestril and Lasix. She is going to receive intravenous vancomycin while in the hospital. Choose the correct statement. The trough is not important; only vancomycin peaks should be monitored She should receive the vancomycin orally due to the risk of further renal insufficiency She is at an elevated risk of ototoxicity She should receive ceftazidime instead of vancomycin Vancomycin should not be used in patients with heart failure

She is at an elevated risk of ototoxicity

Which of the following statements is correct regarding the appropriate use of metronidazole? The IV:PO dosing ratio is 0.5:1 Side effects include a metallic taste in the mouth Alcohol should not be consumed for 7 days after the last dose. Metronidazole is an azole antifungal agent. Metronidazole is available in IV and PO formulations only.

Side effects include a metallic taste in the mouth

Rifaximin may be used in management of all of the following EXCEPT: Refractory C. difficile IBS with diarrhea Spontaneous bacterial peritonitis Hepatic encephalopathy Traveler's diarrhea

Spontaneous bacterial peritonitis

Which of the following statements is incorrect regarding daptomycin? It is associated with myopathy/muscle toxicity, thus monitor for creatine kinase The intravenous formulation is incompatible with D5W It requires dose adjustments for moderate to severe renal impairment The oral formulation has excellent bioavailabiltiy It exhibits concentration-dependent killing

The oral formulation has excellent bioavailabiltiy Only available IV

VK is a 67 year old female with diabetes, overactive bladder and hypothyroidism who has been started on Cipro for treatment of a urinary tract infection, based on susceptibility testing. All of the following counseling points are appropriate for VK EXCEPT: This medication can cause tendon rupture Separate this medication from antacids such as Maalox Monitor blood glucose carefully while taking this medication if you have diabetes This medication is associated with risk of myelosuppression This medication can make the skin more sensitive to the sun. Use sunscreen and protective clothing

This medication is associated with risk of myelosuppression

CP is a 22 year old female who has been started on MacroBID for a five day treatment course of a urinary tract infection. Counseling on MacroBID should include the following points? This drug should be taken on an empty stomach. This medication may cause the urine to turn dark yellow or brown in color. This medication should be taken four times daily in evenly spaced intervals (every 6 hours). Do not take antacids or calcium supplements at the same time as your MacroBID dose. This medication can make the skin more sensitive to the sum. Use sunscreen and protective clothing.

This medication may cause the urine to turn dark yellow or brown in color. Nitrofurantoin (MacroBID) is dosed twice daily, hence the brand name MacroBID. Nitrofurantoin does not have chelation interactions and does not cause photosensitivity. It is associated with GI upset and should be taken with food. The urine discoloration is harmless.

A prescription for generic minocycline is filled. Which of the following statements regarding minocycline are correct? Select all that apply This medication may increase the risk of sunburn This medication should be separated when given with antacids. This medication has been associated with drug-induced lupus. This medication does not interact with other medications. Take on an empty stomach 1 hour before or 2 hours after meals.

This medication may increase the risk of sunburn This medication should be separated when given with antacids. This medication has been associated with drug-induced lupus.

A patient is taking Macrobid for treatment of a urinary tract infection. Which of the following statements regarding Macrobid is correct? This medication may cause the urine to turn blue in color This medication is not absorbed when taken concurrently with food This medication can be used for pyelnephritis The dose is given Q6H This medication should not be used if CrCl is < 60 mL/min

This medication should not be used if CrCl is < 60 mL/min Nitrofurantoin can cause brown urine discoloration. MacroBID is given twice daily. Nitrofurantoin is CI in patients with a creatinine clearance less than 60 mL/min. Nitrofurantoin should be taken with food to enhance absorption and decrease GI upset. Nitrofurantoin is only indicated for uncomplicated cystitis as serum levels are not adequate to treat systemic infections or complicated UTIs. Long term use can lead to serious and fatal pulmonary toxicity.

Extended-infusion piperacillin-tazobactam is a dosing strategy that optimizes which of the following pharmacodynamic parameters? Minimum bactercidal concentration Peak: MIC ratio AUC: MIC ratio Time above MIC (T > MIC) Peak concentration

Time above MIC (T > MIC)

Azithromycin is commonly used in treatment of the following EXCEPT: Toxoplasmosis Chlamydia Gonorrhea Mycobacterium avium complex Traveler's diarrhea

Toxoplasmosis