SulbactamisanirreversIBLeinhibitorofseveralbacterialpenicillinasesandcephalosporinases.Inthepresenceoflowconcentrationsofsulbactam,ampicillinandotherbeta-lactamsreADIlyinhibitthegrowthofavarietyofresistantbacteriathatcontainbeta-lactamases.Sulbactamwasfirstdevelopedbythecentralresearchdivisionofpfizer,Inc.andwasfirstdescribedin1978.Sulbactamusedalonedisplaysonlyweakantibacterialactivity,withthenotableexceptionofitspotenteffectsonsusceptibleandresistantstrainsofNeisseriagonorrhoeae.Sulbactamsodiumappearstobesomewhatlesspotentbutmarkedlymorestable(inaqueoussolution)thanthebeta-lactamaseinhibitorclavulanicacid.

Sulbactamisabletoinhibitthemostcommonformsofβ-lactamasebutisnotabletointeractwiththeAmpCcephalosporinase.Thus,itconferslittleprotectionagainstbacteriasuchasPseudomonasaeruginosa,Citrobacter,Enterobacter,andSerratia,whichoftenexpressthisgene.

Sulbactamiscommonlycombinedwithampicillintoformampicillin/sulbactam(2:1).ItdoespossesssomeantibacterialactivitywhenadmiNISTeredalone,butitistooweaktohaveanyclinicalimportance.

Recently,sulbactamhasbeenusedintreatingAcinetobactersepticemiaandisreceivingrenewedinterest.Synonyms:(2S,5R)-3,3-dimethyl-7-oxo-4-thia-1-azABIcyclo[3.2.0]heptane-2-carboxylicacid4,4-dioxide,Betamaze,CP45899,CP-45,899,Penicillanicacid1,1-dioxide,PenicillanicacidS,S-dioxide,Penicillanicaciddioxide,Penicillanicacidsulfone

CASNumber

68373-14-8

MolecularFormula

C₈H₁₁NO₅S

MolecularWeight

233.24

MechanismofAction

Sulbactamcontainsabeta-lactamringthatbindsstronglytobeta-lactamaseatornearitsactivationsite,therebypermanentlyinhibitingenzymaticactivity.Thisactionprotectsotherbeta-lactamantibiotics(penicillins,cephalosporins,etc.)frombeta-lactamasecatalysis,therebyenhancingtheirantibacterialactivity.Sulbactamalsoshowsantibacterialactivityagainstvariousstrains,sulbactamabletobindtoandinhibitpenicillinbindingproteinsPBP1andPBP3.Thisantibacterialactivityvariesdependingonspecies.

StorageConditions

2-8°C

TariffCode

2941.10.5000

Spectrum

AntimicrobialactivitySulbactamhasveryweakantimicrobialactivityagainstmostbacteria.ItsonlynotableactivityisagainstN.gonorrhoeae,N.meningitidisAcinetobacterbaumannii.Beta-Lactamaseactivity

Sulbactaminhibitsawiderangeofgroup2β-lactamases,includingthosefromStaph.aureus,K.pneumoniaeandB.fragilis.Itisagood-to-moderateinhibitoroftheTEMenzymesofgroups2band2bebuthaslittleeffectongroup1,group2brorgroup3β-lactamases.ItdoesnotinducetheactivityofcephalosporinasesfromGram-negativebacteriabutisaweakinducerofpenicillinasesfromStaph.aureus.

Aconcentrationof4–8mg/Lrestorestheactivityofampicillinformanyβ-lactamase-producingstrainsofStaph.aureus,H.influenzae,Mor.catarrhalis,enterobacteriaandB.fragilis,butthereisalargeinoculumeffect.