54 Questions
What is the primary mechanism of action of cephalosporins?
Inhibition of mucopeptide synthesis in the bacterial cell wall
Why are cefoxitin and cefotetan usually included with the cephalosporins?
Because of their chemical similarity to penicillins
Which classification system is used to divide cephalosporins into five generations?
Order of development
What is the primary reason for grouping cephamycins and carbacephem with cephalosporins?
Chemical similarity
When are cephalosporins most effective against bacteria?
When antibiotic concentrations exceed the pathogen's MIC for at least 50% of the dosing interval
What is the bactericidal effect of cephalosporins dependent on?
Organism susceptibility and tissue concentration
What is the recommended timing for taking Ceftibuten to ensure proper absorption?
1 hour before or 2 hours after meals
Why should cefuroxime axetil tablets and suspension formulations not be used interchangeably?
They have different bioavailabilities
What precaution should patients with phenylketonuria take regarding cefprozil?
Avoid it as it contains phenylalanine
Why must suspensions and antibiotic solutions be shaken before measurement?
To disperse or dissolve drug particles
What should a patient do if severe diarrhea occurs while taking antibiotics?
Contact the prescriber before starting any treatment
How can diabetics taking cephalosporins avoid false positives on urine testing for glucose?
Use blood glucose monitoring
Which cephalosporin should be avoided in neonates at risk for hyperbilirubinemia?
Ceftriaxone
What is the main route of excretion for most cephalosporins?
Kidney
Which generation of cephalosporins does not readily enter the CSF even with meningeal inflammation?
First generation
What is a notable characteristic of ceftriaxone metabolism?
Mainly renal excretion
Which cephalosporin is a prodrug metabolized to active metabolites?
Cefuroxime
Why is ceftriaxone contraindicated in neonates younger than 28 days with hyperbilirubinemia?
Risk of CNS toxicity
Which cephalosporin has high concentrations found in bile?
Cefazolin
What characteristic makes cefuroxime and cefpodoxime unique among cephalosporins?
Metabolized to active metabolites
What is unique about the bioavailability of suspension and tablet formulations of cefpodoxime proxetil and cefixime?
Differences in bioavailability exist between them
Which statement about cephalosporins excretion is correct?
Renal impairment may decrease half-life.
Which patient population might experience serum sickness–like reactions when treated with cephalosporins?
Patients with impaired renal function
What is a common delayed reaction seen with some cephalosporins, usually occurring following a second course of therapy?
Serum sickness–like reactions
Which of the following cephalosporins is not detected in breast milk?
Cefdinir
Under what condition might seizure activity be induced by some parenteral cephalosporins?
In the presence of renal impairment
Which age group has safety and efficacy not been established for when taking cefuroxime?
Children younger than 3 months
Which condition is associated with an increased risk of coagulation abnormalities when administering certain cephalosporins?
Patients with vitamin K synthesis impairment
Which adverse reaction is more likely to occur in patients who receive cefaclor?
Serum sickness–like reactions
What should be done if a patient develops anemia within 2 to 3 weeks of starting cephalosporin therapy?
Evaluate for potential drug involvement and consider stopping the drug
Which oral cephalosporins are associated with a high incidence of non–C.difficile diarrhea?
Cefdinir, cefixime, and cefpodoxime
What potential adverse reaction may occur with ceftriaxone use that clears upon discontinuation of the drug?
Biliary sludge or pseudolithiasis
Which group of bacteria is intrinsically resistant to cephalosporins?
Enterococcus species
Which of the following Enterobacteriaceae is commonly isolated in hospital settings and resistant to first generation cephalosporins?
Serratia species
Which second generation cephalosporin has limited activity against anaerobes like Bacteroides fragilis?
Cefoxitin
Which bacteria are third generation cephalosporins generally active against?
Escherichia coli
Why is the use of third generation cephalosporins discouraged for certain uncommon gram-negative pathogens?
Due to poor ability to detect inducible beta-lactamases
Which of the following bacteria are fourth generation cephalosporins like cefepime resistant against?
Pseudomonas aeruginosa
What is the notable feature of ceftaroline, a fifth generation cephalosporin, compared to third generation cephalosporins?
It has excellent activity against MRSA
Which mechanism of resistance is common among bacteria against cephalosporins?
'Comma separated beta-lactamase production and altered target sites
Which drug can increase the risk for nephrotoxicity when interacting with cephalosporins?
Loop diuretics
Which cephalosporin is recommended as the treatment for gonorrhea because it is resistant to most other antibiotics?
Ceftriaxone
What is the advantage of first generation cephalosporins for penicillin-allergic individuals?
Fairly narrow spectrum
Why are second generation oral cephalosporins preferred for skin and tissue infections over third generation?
Higher activity against gram-positive cocci
Which second generation cephalosporin is not recommended for otitis media in current guidelines due to susceptibility to beta-lactamases?
Cefaclor
What is a key consideration in selecting third generation cephalosporins for infections?
Extended gram-negative spectrum
Which cephalosporin can be dosed once daily for most infections due to its long half-life?
Cefixime
What is a common side effect associated with some cephalosporins that must be distinguished from C.difficile infection?
Diarrhea
Which oral cephalosporin has one of the lowest palatability ratings of all suspensions tested?
Cefpodoxime proxetil
Why should patients who are receiving protracted courses of cefotetan be monitored for prothrombin time (PT)?
To monitor clotting time
What symptom may indicate the need for C.difficile testing in a patient on cephalosporins?
Watery, unformed stools
For which type of infection are third generation parenteral cephalosporins like ceftriaxone and cefotaxime commonly used empirically?
Serious infections presumed to be caused by resistant pneumococci
What must be done if renal impairment is indicated in a patient on certain cephalosporins?
Decrease the dosage according to the schedule
Which parenteral cephalosporin may require administration of exogenous vitamin K if the prothrombin time (PT) is prolonged?
Cefotetan
Learn about the classification and characteristics of cephalosporins, a group of beta-lactam antibiotics related to penicillins. Explore the different generations of cephalosporin drugs and their spectrum of antibacterial activity.
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