Module 9 14 Cephalosporin

Question 1

Question

Answer 1

Answer

Question 2

What are cephalosporins?

Answer 2

Cephalosporins are a class of antibiotics with a structure and mode of action similar to penicillins.

Question 3

How do cephalosporins affect bacteria?

Answer 3

Cephalosporins are bactericidal, meaning they kill bacteria.

Question 4

What is one of the key advantages of cephalosporins in terms of their effectiveness?

Answer 4

Cephalosporins often show resistance to β-lactamases, enzymes that can inactivate β-lactam antibiotics.

Question 5

What is the spectrum of activity for cephalosporins?

Answer 5

Cephalosporins are effective against a broad spectrum of pathogens, making them versatile antibiotics.

Question 6

Are cephalosporins associated with high toxicity?

Answer 6

No, cephalosporins have low toxicity and are well-tolerated.

Question 7

Which class of antibiotics is considered one of the most widely used groups in clinical practice?

Answer 7

Cephalosporins are among the most widely used groups of antibiotics in clinical practice.

Question 8

Are cephalosporins bactericidal or bacteriostatic?

Answer 8

Cephalosporins are bactericidal antibiotics.

Question 9

What is the mechanism of action of cephalosporins?

Answer 9

Cephalosporins bind to penicillin-binding proteins (PBPs) in bacterial cells.

Question 10

What are the two main effects of cephalosporin binding to PBPs?

Answer 10

The two main effects of cephalosporin binding to PBPs are (1) disruption of cell wall synthesis and (2) activation of autolysins, which cleave bonds in the cell wall.

Question 11

How does the damage to the bacterial cell wall lead to cell death?

Answer 11

Damage to the bacterial cell wall leads to cell lysis, resulting in bacterial death.

Question 12

When are cephalosporins most effective against bacterial cells?

Answer 12

Cephalosporins are most effective against bacterial cells that are actively growing and dividing.

Question 13

What is the mechanism of action of cephalosporins?

Answer 13

Cephalosporins bind to penicillin-binding proteins (PBPs) in bacterial cells.

Question 14

What are the two main effects of cephalosporin binding to PBPs?

Answer 14

The two main effects of cephalosporin binding to PBPs are (1) disruption of cell wall synthesis and (2) activation of autolysins, which cleave bonds in the cell wall.

Question 15

How does the damage to the bacterial cell wall lead to cell death?

Answer 15

Damage to the bacterial cell wall causes cell lysis, resulting in bacterial death.

Question 16

When are cephalosporins most effective against bacterial cells?

Answer 16

Cephalosporins are most effective against bacterial cells that are actively growing and dividing.

Question 17

How does bacterial resistance to cephalosporins occur?

Answer 17

Bacterial resistance can result from producing altered penicillin-binding proteins (PBPs) with low affinity for cephalosporins.

Question 18

What is the significance of methicillin-resistant staphylococci (MRSA) in cephalosporin resistance?

Answer 18

MRSA produces altered PBPs, which makes it resistant to most cephalosporins.

Question 19

Which cephalosporin has demonstrated activity against MRSA?

Answer 19

Ceftaroline, a fifth-generation cephalosporin, has shown activity against MRSA.

Question 20

How are cephalosporins categorized into different “generations”?

Answer 20

Cephalosporins are categorized into generations based on the order of their introduction to clinical use.

Question 21

What are the key differences between cephalosporin generations?

Answer 21

Each generation of cephalosporins differs in terms of antimicrobial spectrum, susceptibility to β-lactamases, and the ability to reach the cerebrospinal fluid (CSF).

Question 22

How do characteristics change as you progress from the first-generation to the fifth-generation cephalosporins?

Answer 22

Generally, as you move from the first-generation to the fifth-generation cephalosporins, there is an increase in activity against gram-negative bacteria and anaerobes, resistance to destruction by β-lactamases, and the ability to reach the CSF.

Question 23

What are the key differences between cephalosporin generations in terms of activity against gram-negative bacteria?

Answer 23

Activity against gram-negative bacteria generally increases as you move from the first generation to the fifth generation.

Question 24

How does resistance to β-lactamases change across cephalosporin generations?

Answer 24

Resistance to β-lactamases generally increases as you progress from the first generation to the fifth generation of cephalosporins.

Question 25

What is the difference in distribution to the cerebrospinal fluid (CSF) among cephalosporin generations?

Answer 25

The distribution to CSF generally improves as you move from the first generation to the fifth generation of cephalosporins.

Question 26

Why are many cephalosporins administered parenterally (IM or IV) rather than orally?

Answer 26

Many cephalosporins have poor absorption from the gastrointestinal (GI) tract, making parenteral administration necessary.

Question 27

How many cephalosporins can be administered orally in the United States?

Answer 27

There are 10 cephalosporins that can be administered orally in the United States.

Question 28

Which cephalosporin can be administered both orally and by injection?

Answer 28

Cefuroxime is the cephalosporin that can be administered both orally and by injection in the United States.

Question 29

What is the major route of elimination for cefazolin, a first-generation cephalosporin?

Answer 29

Renal elimination.

Question 30

What is the half-life of cefprozil, a second-generation cephalosporin, in normal renal function?

Answer 30

1.3 hours.

Question 31

In which generation of cephalosporins is ceftriaxone found, and what is its major route of elimination?

Answer 31

Ceftriaxone is a third-generation cephalosporin, and its major route of elimination is hepatic.

Question 32

What is the half-life of cefepime, a fourth-generation cephalosporin, in normal renal function?

Answer 32

2 hours.

Question 33

What is the half-life of ceftaroline, a fifth-generation cephalosporin, in normal renal function?

Answer 33

2.6 hours.

Question 34

Do first- and second-generation cephalosporins reliably penetrate the cerebrospinal fluid (CSF) for the treatment of bacterial meningitis?

Answer 34

No, their penetration to the CSF is unreliable.

Question 35

Which generations of cephalosporins generally achieve sufficient CSF levels for bactericidal effects?

Answer 35

Third, fourth, and fifth generations.

Question 36

How are most cephalosporins eliminated from the body?

Answer 36

Most cephalosporins are eliminated by the kidneys.

Question 37

What is the typical excretion mechanism for cephalosporins?

Answer 37

Excretion involves both glomerular filtration and active tubular secretion.

Question 38

How can probenecid affect the elimination of some cephalosporins?

Answer 38

Probenecid can decrease the tubular secretion of certain cephalosporins, prolonging their effects.

Question 39

Why do patients with renal insufficiency often require reduced dosages of most cephalosporins?

Answer 39

Reduced dosages are necessary to prevent the accumulation of cephalosporins to toxic levels.

Question 40

Is dosage reduction necessary for ceftriaxone in patients with renal impairment?

Answer 40

No, ceftriaxone is primarily eliminated by the liver, and dosage reduction is unnecessary in patients with renal impairment.

Question 41

What is the most common adverse event associated with cephalosporin use?

Answer 41

Hypersensitivity reactions, including maculopapular rash.

Question 42

When does a maculopapular rash typically develop in response to cephalosporin treatment?

Answer 42

Several days after the onset of treatment.

Question 43

Are severe immediate reactions, like bronchospasm and anaphylaxis, common with cephalosporin use?

Answer 43

No, severe immediate reactions are rare but can occur.

Question 44

What action should be taken if signs of allergy (e.g., urticaria, rash, hypotension, difficulty breathing) appear during cephalosporin treatment?

Answer 44

The cephalosporin should be discontinued immediately.

Question 45

What is the recommendation for patients with a history of cephalosporin allergy?

Answer 45

They should avoid cephalosporin drugs.

Question 46

Why is there potential for cross-reactivity between penicillins and cephalosporins?

Answer 46

Because of their structural similarities.

Question 47

What is the typical incidence of cross-reactivity in penicillin-allergic patients when given a cephalosporin?

Answer 47

Approximately 1%.

Question 48

Can patients with mild penicillin allergies use cephalosporins with safety?

Answer 48

Yes, they can often use cephalosporins with minimal concern.

Question 49

What is the recommendation regarding cephalosporin use for patients with a history of severe allergic reactions to penicillins?

Answer 49

Cephalosporins should not be given to such patients due to the potential for fatal anaphylaxis.

Question 50

Which cephalosporins can induce alcohol intolerance and a disulfiram-like reaction?

Answer 50

Cefazolin and cefotetan.

Question 51

What is the disulfiram effect, and what causes it?

Answer 51

The disulfiram effect is a reaction caused by the accumulation of acetaldehyde, and it results from the inhibition of aldehyde dehydrogenase.

Question 52

What is the recommendation for patients taking cefazolin and cefotetan concerning alcohol consumption?

Answer 52

They must avoid consuming alcohol in any form to prevent a disulfiram-like reaction.

Question 53

Which cephalosporins can interfere with Vitamin K metabolism and potentially inhibit the formation of clotting factors?

Answer 53

Cefotetan, cefazolin, and ceftriaxone.

Question 54

Why is caution necessary when combining these cephalosporins with other agents?

Answer 54

Because they can promote bleeding, and when combined with agents like anticoagulants, thrombolytics, NSAIDs, or antiplatelet drugs, the risk of bleeding increases.

Question 55

What are the key characteristics of cephalosporins as antimicrobial drugs?

Answer 55

Cephalosporins are broad-spectrum, bactericidal drugs with a high therapeutic index.

Question 56

How have cephalosporins been historically employed in the treatment of infections?

Answer 56

Cephalosporins have been widely and successfully used against a variety of infections.

Question 57

For which group of patients can cephalosporins be valuable alternatives, especially if they have a mild penicillin allergy?

Answer 57

Patients with mild penicillin allergy can consider cephalosporins as alternatives.

Question 58

How do the five generations of cephalosporins differ in their applications?

Answer 58

The five generations of cephalosporins have distinct applications.

Question 59

Are first- and second-generation cephalosporins commonly the preferred choice for most active infections?

Answer 59

No, first- and second-generation cephalosporins are rarely the preferred choice for active infections, except for infections caused by sensitive staphylococci.

Question 60

Which generation of cephalosporins is often preferred for treating several infections?

Answer 60

Third-generation cephalosporins are often the preferred therapy for various infections.

Question 61

In what capacity are fourth- and fifth-generation cephalosporins particularly effective?

Answer 61

Fourth- and fifth-generation agents are effective against resistant organisms.

Question 62

For which types of infections is the fifth-generation cephalosporin commonly used?

Answer 62

The fifth-generation agent is used to treat skin infections, including MRSA, and health care-associated pneumonias.

Question 63

Which generation of cephalosporins has the highest activity against gram-positive organisms such as staphylococci and streptococci?

Answer 63

The first-generation cephalosporins have the highest activity against gram-positive organisms.

Question 64

What is the preferred use of first-generation cephalosporins?

Answer 64

First-generation cephalosporins are used in patients with mild penicillin allergy and for surgical prophylaxis.

Question 65

Which organisms are targeted by second-generation cephalosporins?

Answer 65

Second-generation cephalosporins have a broader spectrum, including gram-positive and gram-negative organisms like Haemophilus influenzae, Klebsiella, pneumococci, and staphylococci.

Question 66

What are the preferred uses of second-generation cephalosporins?

Answer 66

Second-generation cephalosporins are used for otitis, sinusitis, and respiratory tract infections.

Question 67

Which generation of cephalosporins is preferred for treating meningitis and has broad activity against gram-negative organisms?

Answer 67

Third-generation cephalosporins are preferred for treating meningitis and have a broad spectrum against gram-negative organisms.

Question 68

Against which organisms are fourth-generation cephalosporins mainly effective, and what infections are they used for?

Answer 68

Fourth-generation cephalosporins are mainly effective against Pseudomonas aeruginosa and are used for hospital-acquired pneumonia and complicated intra-abdominal and urinary tract infections.

Question 69

What is the primary target of fifth-generation cephalosporins, and what types of infections are they used for?

Answer 69

Fifth-generation cephalosporins primarily target gram-positive organisms, especially methicillin-resistant Staphylococcus aureus (MRSA), and are used for MRSA-associated infections.

Question 70

What is the category of drugs that inhibit cell wall synthesis, and name the prototype drugs in this category?

Answer 70

The category of drugs that inhibit cell wall synthesis includes cephalosporins, carbapenems, and vancomycin.

Question 71

Which drug is a prototype of cephalosporins?

Answer 71

Cephalexin is a prototype of cephalosporins.

Question 72

Which drug is a prototype of carbapenems?

Answer 72

Imipenem is a prototype of carbapenems.

Question 73

Name a drug in the "other" category of drugs that inhibit cell wall synthesis.

Answer 73

Vancomycin belongs to the "other" category of drugs that inhibit cell wall synthesis.

Question 74

How many cephalosporins are currently available in the United States?

Answer 74

There are 19 cephalosporins available in the United States.

Question 75

Why can selecting among cephalosporins be challenging?

Answer 75

The similarities among cephalosporins within each generation are more pronounced than the differences.

Question 76

What is often the primary basis for choosing one cephalosporin over another in the outpatient setting?

Answer 76

Cost is often the primary basis for choosing a cephalosporin over another in the outpatient setting.

Question 77

Into which three main categories can the differences between cephalosporins be grouped?

Answer 77

The differences between cephalosporins can be grouped into three main categories: antimicrobial spectrum, adverse effects, and pharmacokinetics.

Question 78

What is the dosage range for Cefadroxil (PO) in adults, and what is the recommended dosage for children?

Answer 78

Adults: 1-2 g every 12-24 hours; Children: 30 mg/kg

Question 79

How often is Cefazolin (IM, IV) typically administered in adults, and what is the dosage range for children?

Answer 79

Adults: 2-12 g every 6-8 hours; Children: 80-160 mg/kg

Question 80

What is the recommended dosage and dosing interval for Cephalexin (PO) in adults and children?

Answer 80

Adults: 1-4 g every 6 hours; Children: 25-100 mg/kg

Question 81

What is the therapeutic goal of cephalosporin treatment?

Answer 81

The therapeutic goal of cephalosporin treatment is to treat infections caused by susceptible organisms.

Question 82

Why is it important to collect baseline data in cephalosporin therapy, and what type of data should be collected?

Answer 82

Baseline data helps identify the infecting organism and its sensitivity. Collect samples for culture.

Question 83

Is routine laboratory monitoring necessary during cephalosporin treatment?

Answer 83

No, routine laboratory monitoring is not required.

Question 84

Who should avoid cephalosporin treatment due to contraindications?

Answer 84

Patients with a history of allergic reactions to cephalosporins or severe reactions to penicillin should avoid cephalosporin treatment.

Question 85

How can you evaluate the therapeutic effects of cephalosporin treatment?

Answer 85

Monitor for indications of antimicrobial effects, such as reduced fever, pain, edema, and inflammation.

Question 86

What potential adverse effect should patients be instructed to report during cephalosporin treatment?

Answer 86

Patients should report any increase in stool frequency, as cephalosporins can increase the risk of Clostridium difficile infection.