cephalosporins Flashcards
Question: What are the common uses of cephalosporins in the treatment of infections?
Answer: Cephalosporins are used to treat a wide range of infections, including septicaemia, pneumonia, meningitis, biliary-tract infections, peritonitis, and urinary-tract infections.
Question: How do the pharmacokinetics of cephalosporins compare to penicillins, and what is the primary route of excretion for cephalosporins?
Answer: The pharmacokinetics of cephalosporins are similar to penicillins, and they are primarily excreted through the renal system.
Question: When do cephalosporins penetrate cerebrospinal fluid effectively, and which specific cephalosporins are suitable for central nervous system (CNS) infections such as meningitis?
Answer: Cephalosporins penetrate cerebrospinal fluid poorly unless the meninges are inflamed. For CNS infections like meningitis, cefotaxime and ceftriaxone are suitable cephalosporin choices due to their better penetration of the CNS.
Question: What are the common uses of cephalosporins in the treatment of infections?
Answer: Cephalosporins are used to treat a wide range of infections, including septicaemia, pneumonia, meningitis, biliary-tract infections, peritonitis, and urinary-tract infections.
Question: How do the pharmacokinetics of cephalosporins compare to penicillins, and what is the primary route of excretion for cephalosporins?
Answer: The pharmacokinetics of cephalosporins are similar to penicillins, and they are primarily excreted through the renal system.
Question: When do cephalosporins penetrate cerebrospinal fluid effectively, and which specific cephalosporins are suitable for central nervous system (CNS) infections such as meningitis?
Answer: Cephalosporins penetrate cerebrospinal fluid poorly unless the meninges are inflamed. For CNS infections like meningitis, cefotaxime and ceftriaxone are suitable cephalosporin choices due to their better penetration of the CNS.
Question: What is the principal side-effect associated with cephalosporins?
Answer: The primary side-effect of cephalosporins is hypersensitivity.
Question: Is there cross-reactivity between penicillins and cephalosporins in patients with penicillin allergies, and if so, how common is it?
Answer: Cross-reactivity between penicillins and first and early second-generation cephalosporins has been reported in up to 10% of penicillin-allergic patients. For third-generation cephalosporins, cross-reactivity occurs in 2–3% of penicillin-allergic patients.
Question: When a cephalosporin is necessary in penicillin-allergic patients, which cephalosporins can be used with caution, and which ones should be avoided?
Answer: In penicillin-allergic patients, cefixime, cefotaxime, ceftazidime, ceftriaxone, and cefuroxime can be used with caution when no suitable alternative is available. Cefaclor, cefadroxil, cefalexin, cefradine, and ceftaroline fosamil should be avoided in such cases.
Question: What is the principal side-effect associated with cephalosporins?
Answer: The primary side-effect of cephalosporins is hypersensitivity.
Question: Is there cross-reactivity between penicillins and cephalosporins in patients with penicillin allergies, and if so, how common is it?
Answer: Cross-reactivity between penicillins and first and early second-generation cephalosporins has been reported in up to 10% of penicillin-allergic patients. For third-generation cephalosporins, cross-reactivity occurs in 2–3% of penicillin-allergic patients.
Question: When a cephalosporin is necessary in penicillin-allergic patients, which cephalosporins can be used with caution, and which ones should be avoided?
Answer: In penicillin-allergic patients, cefixime, cefotaxime, ceftazidime, ceftriaxone, and cefuroxime can be used with caution when no suitable alternative is available. Cefaclor, cefadroxil, cefalexin, cefradine, and ceftaroline fosamil should be avoided in such cases.
Question: What is the antimicrobial spectrum of ‘first generation’ cephalosporins like cefalexin, cefradine, and cefadroxil, as well as the ‘second generation’ cephalosporin cefaclor?
Answer: Cefalexin, cefradine, cefadroxil, and cefaclor have a similar antimicrobial spectrum. They are useful for urinary-tract infections, respiratory-tract infections, otitis media, and skin and soft-tissue infections.
Question: Which cephalosporin has good activity against H. influenzae?
Answer: Cefaclor has good activity against Haemophilus influenzae.
Question: Among these cephalosporins, which one has a long duration of action and can be administered twice daily?
Answer: Cefadroxil has a long duration of action and can be given twice daily.
Question: What is special about cefuroxime axetil, an ester of the ‘second generation’ cephalosporin cefuroxime?
Answer: Cefuroxime axetil has the same antibacterial spectrum as its parent compound (cefuroxime). It is poorly absorbed and needs to be administered with food to maximize absorption.
Question: What is the unique feature of Cefixime among cephalosporins?
Answer: Cefixime is an orally active ‘third generation’ cephalosporin with a longer duration of action compared to other oral cephalosporins. It is only licensed for acute infections.
Question: How does Cefuroxime differ from earlier cephalosporins in terms of susceptibility to inactivation by beta-lactamases and its activity?
Answer: Cefuroxime is a ‘second generation’ cephalosporin that is less susceptible to inactivation by beta-lactamases. It has greater activity against Haemophilus influenzae and certain bacteria resistant to other drugs.
Question: What are the key features of ‘third generation’ cephalosporins like Cefotaxime, Ceftazidime, and Ceftriaxone?
Answer: They have greater activity against certain Gram-negative bacteria but are less active against Gram-positive bacteria, especially Staphylococcus aureus. Their broad spectrum may encourage superinfection with resistant bacteria or fungi. Ceftazidime has good activity against Pseudomonas, while Ceftriaxone has a longer half-life and can be given once daily.
Question: What is unique about Ceftaroline fosamil, a ‘fifth generation’ cephalosporin?
Answer: Ceftaroline fosamil has an extended spectrum of activity against Gram-positive bacteria, including meticillin-resistant Staphylococcus aureus and multi-drug resistant Streptococcus pneumoniae. It is licensed for treating community-acquired pneumonia and complicated skin and soft-tissue infections.
Question: What is the specialty of Cefiderocol in the world of cephalosporins?
Answer: Cefiderocol is a siderophore cephalosporin used for treating infections caused by Gram-negative aerobic organisms when other treatment options have failed.
Regenerate
Question: What is the unique feature of Cefixime among cephalosporins?
Answer: Cefixime is an orally active ‘third generation’ cephalosporin with a longer duration of action compared to other oral cephalosporins. It is only licensed for acute infections.
Question: How does Cefuroxime differ from earlier cephalosporins in terms of susceptibility to inactivation by beta-lactamases and its activity?
Answer: Cefuroxime is a ‘second generation’ cephalosporin that is less susceptible to inactivation by beta-lactamases. It has greater activity against Haemophilus influenzae and certain bacteria resistant to other drugs.
Question: What are the key features of ‘third generation’ cephalosporins like Cefotaxime, Ceftazidime, and Ceftriaxone?
Answer: They have greater activity against certain Gram-negative bacteria but are less active against Gram-positive bacteria, especially Staphylococcus aureus. Their broad spectrum may encourage superinfection with resistant bacteria or fungi. Ceftazidime has good activity against Pseudomonas, while Ceftriaxone has a longer half-life and can be given once daily.
Question: What is unique about Ceftaroline fosamil, a ‘fifth generation’ cephalosporin?
Answer: Ceftaroline fosamil has an extended spectrum of activity against Gram-positive bacteria, including meticillin-resistant Staphylococcus aureus and multi-drug resistant Streptococcus pneumoniae. It is licensed for treating community-acquired pneumonia and complicated skin and soft-tissue infections.
Question: What is the specialty of Cefiderocol in the world of cephalosporins?
Answer: Cefiderocol is a siderophore cephalosporin used for treating infections caused by Gram-negative aerobic organisms when other treatment options have failed.
Regenerate
