Cephalosporins - Cephradine

Question 1

What are oral cephalosporins used for?

Answer 1

oral cephalosporins are used as 2nd and 3rd line treatment for urinary and respiratory tract infections.

Question 2

What are IV cephalosporins and carbapenems used for?

Answer 2

IV cephalosporins and carbapenems are for treatment of infections that are very severe or complicated or caused by Abx resistant organisms.

Question 3

How do cephalosporins and carbapenems work?

Answer 3

They are similar to penicillin as they have a beta lactam ring. They inhibit enzymes responsible for peptidoglycan cross linking in cell walls. This weakens cell walls leading to bacterial cell swelling, lysis and death.

Question 4

What is the spectrum of cephalosporins and carbapenems?

Answer 4

broad spec

Question 5

What is cefradine (cephalosporin) used for?

Answer 5

• Respiratory tract infections caused by group A beta-hemolytic streptococci and S.pneumoniae.
• Otitis media caused by group A beta-hemolytic streptococci, s.pneumoniae, H.influenzae, staphylococci.
• Skin and skin structure infections caused by staphylococci and beta-hemolytic streptococci.
• Urinary tract infections including prostatitis caused by E.coli, Klebsiella.

Question 6

what are the side effects of cephalosporins and carbepenems?

Answer 6

• GI upset (nausea / diarrhoea)
• Antibiotic associated colitis (C.DIFF)
• Allergic reactions (penicillin allergic patients)
• central nervous system toxicity —> seizures

Question 7

When is central nervous system toxicity and siezures particularly risky

Answer 7

when carbapenems are given at high doses to patients with renal impairments.

Question 8

What conditions should carbapenems be used in caution with/

Answer 8

1) epilepsy —> risk of seizures

2) renal impairment (dose reduction required)

Question 9

Why are cephalosporins contraindicated with aminoglycosides?

Answer 9

Cephalosporins increased the nephrotoxicity of aminoglycosides

Question 10

Why are cephalosporins and carbapenems contraindicated with warfarin?

Answer 10

They are broad spec, so kill the gut flora that normally produce vit K. So the anticoagulant effect of warfarin is enhanced.

Question 11

How to carbapenems affect valproate?

Answer 11

They reduce the plasma concentrations and efficacy of valproate.