BNF for Children 2011-2012

266 5.1.2 Cephalosporins, carbapenems, and other beta-lactams BNFC 2011–20125 Infectionsstrictures, gastro-intestinal obstruction, infants under3 monthsPregnancy not known to be harmful, but manufactureradvises avoidBreast-feeding trace amounts in milkSide-effects see under Benzylpenicillin (section5.1.1.1); nausea, vomiting, dyspepsia; also reducedserum and total body carnitine (especially with longtermor repeated use)Licensed use not licensed for use in children under 3monthsIndication and doseAcute uncomplicated cystitis. By mouthChild body-weight over 40 kg initially 400 mgthen 200 mg every 8 hours for 3 daysChronic or recurrent bacteriuriaChild body-weight over 40 kg 400 mg every 6–8hoursUrinary-tract infectionsChild body-weight under 40 kg 5–10 mg/kgevery 6 hours; total daily dose may alternatively begiven in 3 divided dosesSalmonellosis not recommended therefore no dosestatedCounselling Tablets should be swallowed whole with plentyof fluid during meals while sitting or standingSelexid c (LEO) ATablets, f/c, pivmecillinam hydrochloride 200 mg, netprice 10-tab pack = £4.50. Label: 9, 21, 27, counselling,posture (see Dose above)5.1.2 Cephalosporins,carbapenems, and otherbeta-lactamsAntibiotics in this section include the cephalosporins,such as cefotaxime, ceftazidime, cefuroxime, cefalexinand cefradine, the monobactam, aztreonam, and thecarbapenems, imipenem (a thienamycin derivative),meropenem, and ertapenem.5.1.2.1 CephalosporinsThe cephalosporins are broad-spectrum antibacterialswhich are used for the treatment of septicaemia, pneumonia,meningitis, biliary-tract infections, peritonitis,and urinary-tract infections. The pharmacology of thecephalosporins is similar to that of the penicillins, excretionbeing principally renal. Cephalosporins penetratethe cerebrospinal fluid poorly unless the meninges areinflamed; cefotaxime and ceftriaxone are suitable cephalosporinsfor infections of the CNS (e.g meningitis).The principal side-effect of the cephalosporins is hypersensitivityand about 0.5–6.5% of penicillin-sensitivepatients will also be allergic to the cephalosporins.Patients with a history of immediate hypersensitivityto penicillin should not receive a cephalosporin. If acephalosporin is essential in these patients because asuitable alternative antibacterial is not available, thencefixime, cefotaxime, ceftazidime, ceftriaxone, or cefuroximecan be used with caution; cefaclor, cefadroxil,cefalexin, and cefradine should be avoided.Antibiotic-associated colitis may occur with the use ofbroad-spectrum cephalosporins, particularly secondandthird-generation cephalosporins.Cefuroxime is a ‘second generation’ cephalosporin thatis less susceptible than the earlier cephalosporins toinactivation by beta-lactamases. It is, therefore, activeagainst certain bacteria that are resistant to the otherdrugs and has greater activity against Haemophilusinfluenzae.Cefotaxime, ceftazidime and ceftriaxone are ‘thirdgeneration’ cephalosporins with greater activity thanthe ‘second generation’ cephalosporins against certainGram-negative bacteria. However, they are less activethan cefuroxime against Gram-positive bacteria, mostnotably Staphylococcus aureus. Their broad antibacterialspectrum may encourage superinfection withresistant bacteria or fungi.Ceftazidime has good activity against pseudomonas. Itis also active against other Gram-negative bacteria.Ceftriaxone has a longer half-life and therefore needs tobe given only once daily. Indications include seriousinfections such as septicaemia, pneumonia, andmeningitis. The calcium salt of ceftriaxone forms aprecipitate in the gall bladder which may rarely causesymptoms but these usually resolve when the antibacterialis stopped. In neonates, ceftriaxone may displacebilirubin from plasma-albumin and should beavoided in neonates with unconjugated hyperbilirubinaemia,hypoalbuminaemia, acidosis or impaired bilirubinbinding.Orally active cephalosporins The orally active ‘firstgeneration’ cephalosporins, cefalexin, cefradine, andcefadroxil and the ‘second generation’ cephalosporin,cefaclor, have a similar antimicrobial spectrum. Theyare useful for urinary-tract infections which do notrespond to other drugs or which occur in pregnancy,respiratory-tract infections, otitis media, sinusitis, andskin and soft-tissue infections. Cefaclor has good activityagainst H. influenzae, but it is associated withprotracted skin reactions especially in children. Cefadroxilhas a long duration of action and can be giventwice daily; it has poor activity against H. influenzae.Cefuroxime axetil, an ester of the ‘second generation’cephalosporin cefuroxime, has the same antibacterialspectrum as the parent compound; it is poorly absorbedand needs to be given with food to maximise absorption.Cefixime and cefpodoxime proxetil are orally active‘third generation’ cephalosporins. Cefixime has a longerduration of action than the other cephalosporins that areactive by mouth. It is only licensed for acute infections.Cefpodoxime proxetil is more active than the other oralcephalosporins against respiratory bacterial pathogensand it is licensed for upper and lower respiratory-tractinfections.For treatment of Lyme disease, see section 5.1.1.3.Oral infections The cephalosporins offer little advantageover the penicillins in dental infections, often beingless active against anaerobes. Infections due to oralstreptococci (often termed viridans streptococci)