Medical Microbiology

ThePrinciplesofAntibioticTherapy 193

Table3. 4 Continued:FrequentlyUsedAnti-InfectiveAgents

Class/activesubstance Remarks

Penicillins

Classicpenicillins

penicillinG(benzylpenicillin),

penicillinV(oralpenicillin),

pheneticillin,propicillin

EffectiveagainstGram-positivebacteriaand

Gram-negativecocci;bactericidaleffectduring

bacterialcelldivisionphase;inactivatedby

penicillinaseofstaphylococci,gonococci,

Haemophilusinfluenzae,Moraxellacatarrhalis

Penicillinase-resistantpenicillins

methicillin,oxacillin,

cloxacillin,flucloxacillin

Stableinthepresenceofpenicillinaseofstaphylo-

cocci;agentofchoiceinstaphylococciinfections

(flucloxacillin)

Aminopenicillins

ampicillin,amoxicillin,

epicillin,hetacillin,etc.

AlsoeffectiveagainstEnterobacteriaceae;

labileagainstGram-positiveandGram-negative

penicillinases

Carboxylpenicillins

carbenicillin,ticarcillin,

carfecillin,etc.

EffectiveagainstEnterobacteriaceaeand

Pseudomonas;labileagainstGram-positiveand

Gram-negativepenicillinases

temocillin(6-a-methoxy

ticarcillin)

NoeffectagainstPseudomonas;highlystableinthe

presenceofbetalactamases

Acylureidopenicillins

azlocillin,mezlocillin,

piperacillin,apalcillin

EffectiveagainstEnterobacteriaceaeand

Pseudomonas;despitelabilityagainstbeta-

lactamasesactiveagainstmanyenzyme-producing

strainsduetogoodpenetrationandhighlevelsof

sensitivityofthetargetmolecules

Penems Penicillinswithadoublebondinthesecondring

system

N-formimidoylthienamycin

(imipenem=

N-F-thienamycin+

cilastatin)

Acarbapenem(Catominsteadofsulfurinsecond

ring);verybroadspectrumandhighlevelof

activityagainstGram-positiveandGram-negative

bacteria,includinganaerobes;frequentlyeffective

againstEnterobacteriaceaeandPseudomonaswith

resistancetothecephalosporinsofGroup3b;

inactivatedbyrenalenzymes;istherefore

administeredincombinationwiththeenzyme

inhibitorcilastatin

3

Kayser, Medical Microbiology © 2005 Thieme