clobutinol clobutinol clobutinol is a cough suppressant formerly distributed by boehringer ingelheim and its licensees under the names lomisat and silomat, by bioter as biotussin, and by violani-farmavigor as pertoxil. it has been withdrawn from the market worldwide. clobutinolclinical datatrade namesbiotussin, lomisat, pertoxil, silomatahfs/drugs.cominternational drug namesroutes ofadministrationoralatc coder05db03 (who) legal statuslegal status withdrawn (eu)identifiers iupac name (rs)-1-(4-chlorophenyl)-4-dimethylamino-2,3-dimethyl-butan-2-ol cas number14860-49-2 ypubchem cid26937drugbankdb09004 nchemspider25085 yunii1ny2ix043akeggd07716 ychemblchembl1474889 ncomptox dashboard (epa)dtxsid2022838 echa infocard100.035.373 chemical and physical dataformulac14h22clnomolar mass255.79 g·mol−13d model (jsmol)interactive imagechiralityracemic mixture smiles clc1ccc(cc1)cc(o)(c)c(c)cn(c)c inchi inchi=1s/c14h22clno/c1-11(10-16(3)4)14(2,17)9-12-5-7-13(15)8-6-12/h5-8,11,17h,9-10h2,1-4h3 ykey:kvhhqgiizcjatj-uhfffaoysa-n y ny (what is this?) (verify) side effects and withdrawal side effects include drowsiness, dizziness, insomnia, nausea, vomiting, and abdominal discomfort. studies in 2004 had indicated that clobutinol has the potential to prolong the qt interval. clobutinol was in 2007 determined to cause cardiac arrhythmia in some patients. boehringer ingelheim products containing clobutinol were voluntarily withdrawn from sale in germany, and the rest of the world, on august 31, 2007. the approval for germany and the eu was revoked in 2008. prior to withdrawal, it was available throughout europe and central america, as well as in south africa. trade names include biotussin, lomisat (spain), pertoxil (italy), and in most of the world, silomat. synthesis patents: the mannich reaction of 2-butanone (1) with formaldehyde and dimethylamine gives 4-dimethylamino-3-methyl-2-butanone (2). grignard reaction with 4-chlorobenzylchloride (3) afforded clobutinol (4).