cloxacillin cloxacillin cloxacillin is an antibiotic useful for the treatment of a number of bacterial infections. this includes impetigo, cellulitis, pneumonia, septic arthritis, and otitis externa. it is not effective for methicillin-resistant staphylococcus aureus (mrsa). it is used by mouth and by injection. cloxacillinclinical datatrade namescloxapen, othersahfs/drugs.commicromedex detailed consumer informationroutes ofadministrationby mouth, imatc codej01cf02 (who) qj51cf02 (who) qs01aa90 (who)pharmacokinetic databioavailability37 to 90%protein binding95%elimination half-life30 minutes to 1 hourexcretionkidney and biliaryidentifiers iupac name (2s,5r,6r)-6--3,3-dimethyl-7-oxo-4-thia-1-azabicycloheptane-2-carboxylic acid or 5 methyl 3(2 chlorophenyl)4 isoxazoyl penicillin cas number61-72-3 ypubchem cid6098drugbankdb01147 ychemspider5873 yuniio6x5qgc2vbkeggd07733 ychebichebi:49566 ychemblchembl891 ycomptox dashboard (epa)dtxsid5022853 echa infocard100.000.468 chemical and physical dataformulac19h18cln3o5smolar mass435.88 g·mol−13d model (jsmol)interactive image smiles o=c(o)3n4c(=o)(nc(=o)c2c(onc2c1ccccc1cl)c)4sc3(c)c inchi inchi=1s/c19h18cln3o5s/c1-8-11(12(22-28-8)9-6-4-5-7-10(9)20)15(24)21-13-16(25)23-14(18(26)27)19(2,3)29-17(13)23/h4-7,13-14,17h,1-3h3,(h,21,24)(h,26,27)/t13-,14+,17-/m1/s1 ykey:lqolirlgbulykd-jkifevaisa-n y (verify) side effects include nausea, diarrhea, and allergic reactions including anaphylaxis. clostridium difficile diarrhea may also occur. it is not recommended in people who have previously had a penicillin allergy. use during pregnancy appears to be relatively safe. cloxacillin is in the penicillin family of medications. cloxacillin was patented in 1960 and approved for medical use in 1965. it is on the world health organization's list of essential medicines. it is not commercially available in the united states. mechanism of action it is semisynthetic and in the same class as penicillin. cloxacillin is used against staphylococci that produce beta-lactamase, due to its large r chain, which does not allow the beta-lactamases to bind. this drug has a weaker antibacterial activity than benzylpenicillin, and is devoid of serious toxicity except for allergic reactions. society and culture cloxacillin was discovered and developed by beecham (now glaxosmithkline). it is sold under a number of trade names, including cloxapen, cloxacap, tegopen and orbenin.