Cefixime is an orally active‘third generation’cephalosporin.
It has a longer duration of action than the other
cephalosporins that are active by mouth. It is only licensed
for acute infections.
Cefuroxime is a‘second generation’cephalosporin that is
less susceptible than the earlier cephalosporins to
inactivation by beta-lactamases. It is, therefore, active
against certain bacteria which are resistant to the other
drugs and has greater activity againstHaemophilus
influenzae.
Cefotaxime, ceftazidime and ceftriaxone are‘third
generation’cephalosporins with greater activity than the
‘second generation’cephalosporins against certain Gram-
negative bacteria. However, they are less active than
cefuroxime against Gram-positive bacteria, most notably
Staphylococcus aureus. Their broad antibacterial spectrum
may encourage superinfection with resistant bacteria or
fungi.
Ceftazidime has good activity against pseudomonas. It is
also active against other Gram-negative bacteria.
Ceftriaxone has a longer half-life and therefore needs to be
given only once daily. Indications include serious infections
such as septicaemia, pneumonia, and meningitis. The
calcium salt of ceftriaxone forms a precipitate in the gall
bladder which may rarely cause symptoms but these usually
resolve when the antibacterial is stopped. In neonates,
ceftriaxone may displace bilirubin from plasma-albumin and
should be avoided in neonates with unconjugated
hyperbilirubinaemia, hypoalbuminaemia, acidosis or
impaired bilirubin binding.
Cephalosporins f
lDRUG ACTIONCephalosporins are antibacterials that
attach to penicillin binding proteins to interrupt cell wall
biosynthesis, leading to bacterial cell lysis and death.
lSIDE-EFFECTS
▶Common or very commonAbdominal pain.diarrhoea.
dizziness.eosinophilia.fungal infection.headache.
leucopenia.nausea.neutropenia.skin reactions.
thrombocytopenia.vomiting
▶UncommonAnaphylactic reaction.antibiotic associated
colitis
▶Rare or very rareAgranulocytosis.angioedema.
haemolytic anaemia.nephritis tubulointerstitial
(reversible).severe cutaneous adverse reactions (SCARs)
lALLERGY AND CROSS-SENSITIVITYContra-indicated in
patients with cephalosporin hypersensitivity.
▶Cross-sensitivity with other beta-lactam antibacterialsAbout
0. 5 – 6. 5 % of penicillin-sensitive patients will also be
allergic to the cephalosporins. Patients with a history of
immediate hypersensitivityto penicillin and other beta-
lactams should not receive a cephalosporin.
Cephalosporins should be used with caution in patients
with sensitivity to penicillin and other beta-lactams.
lEFFECT ON LABORATORY TESTSFalse positive urinary
glucose (if tested for reducing substances). False positive
Coombs’test.
ANTIBACTERIALS›CEPHALOSPORINS,
FIRST-GENERATION
eiiiiFaboveCefadroxil
lINDICATIONS AND DOSE
Susceptible infections due to sensitive Gram-positive and
Gram-negative bacteria
▶BY MOUTH
▶Child 6–17 years (body-weight up to 40 kg): 0. 5 g twice
daily
▶Child 6–17 years (body-weight 40 kg and above): 0. 5 – 1 g
twice daily
Skin infections|Soft-tissue infections|Uncomplicated
urinary-tract infections
▶BY MOUTH
▶Child 6–17 years (body-weight 40 kg and above): 1 g once
dailylINTERACTIONS→Appendix 1 : cephalosporins
lSIDE-EFFECTS
▶Common or very commonDyspepsia.glossitis
▶Rare or very rareArthralgia.autoimmune haemolytic
anaemia.drug fever.fatigue.hepatic disorders.insomnia
.nervousness.serum sickness-like reaction
lPREGNANCYNot known to be harmful.
lBREAST FEEDINGPresent in milk in low concentration, but
appropriate to use.
lRENAL IMPAIRMENT
Dose adjustmentsReduce dose if estimated glomerular
filtration rate less than 50 mL/minute/ 1. 73 m^2.lMEDICINAL FORMS
There can be variation in the licensing of different medicines
containing the same drug.
Capsule
CAUTIONARY AND ADVISORY LABELS 9
▶Cefadroxil (Non-proprietary)
Cefadroxil (as Cefadroxil monohydrate) 500 mgCefadroxil 500 mg
capsules| 20 capsuleP£ 22. 38 DT = £ 15. 24 | 100 capsuleP
£ 26. 22 – £ 111. 90eiiiiFaboveCefalexin
(Cephalexin)
lINDICATIONS AND DOSE
Susceptible infections due to sensitive Gram-positive and
Gram-negative bacteria
▶BY MOUTH
▶Neonate up to 7 days: 25 mg/kg twice daily (max. per dose
125 mg).▶Neonate 7 days to 20 days: 25 mg/kg 3 times a day (max.
per dose 125 mg).▶Neonate 21 days to 28 days: 25 mg/kg 4 times a day (max.
per dose 125 mg).▶Child 1–11 months: 12. 5 mg/kg twice daily, alternatively
125 mg twice daily
▶Child 1–4 years: 12. 5 mg/kg twice daily, alternatively
125 mg 3 times a day
▶Child 5–11 years: 12. 5 mg/kg twice daily, alternatively
250 mg 3 times a day
▶Child 12–17 years: 500 mg 2 – 3 times a day continued→BNFC 2018 – 2019 Bacterial infection 317
Infection5