moracizine moracizine moracizine or moricizine, sold under the trade name ethmozine, is an antiarrhythmic of class ic. it was used for the prophylaxis and treatment of serious and life-threatening ventricular arrhythmias, but was withdrawn in 2007 for commercial reasons. moracizineclinical datatrade namesethmozineother namesmoricizine (usan us)ahfs/drugs.comconsumer drug informationmedlineplusa601214pregnancycategory b (u.s.) atc codec01bg01 (who) pharmacokinetic databioavailability34–38%protein binding95%elimination half-life3–4 hours (healthy volunteers), 6–13 hours (cardiac disease)identifiers iupac name ethyl carbamate cas number31883-05-3 ypubchem cid34633iuphar/bps7244drugbankdb00680 nchemspider31872 yunii2gt1d0tmx1keggd05077 ychebichebi:6997 ychemblchembl1075 ycomptox dashboard (epa)dtxsid4023335 echa infocard100.046.216 chemical and physical dataformulac22h25n3o4smolar mass427.52 g·mol−13d model (jsmol)interactive image smiles o=c(occ)nc2cc1n(c3c(sc1cc2)cccc3)c(=o)ccn4ccocc4 inchi inchi=1s/c22h25n3o4s/c1-2-29-22(27)23-16-7-8-20-18(15-16)25(17-5-3-4-6-19(17)30-20)21(26)9-10-24-11-13-28-14-12-24/h3-8,15h,2,9-14h2,1h3,(h,23,27) ykey:fubvwmnbehxpsu-uhfffaoysa-n y ny (what is this?) (verify) pharmacology moracizine, a phenothiazine derivative, undergoes extensive first-pass metabolism and is also extensively metabolized after it has entered the circulation. it may have pharmacologically active metabolites. a clinical study has shown that moracizine is slightly less effective than encainide or flecainide in suppressing ventricular premature depolarizations. compared with disopyramide and quinidine, moracizine was equally or more effective in suppressing premature ventricular contractions, couplets, and nonsustained ventricular tachycardia. in the cardiac arrhythmia suppression trial (cast), a large study testing the influence of antiarrhythmics on mortality, showed a statistically non-significant increase of mortality from 5.4 to 7.2% under moracizine. this is in line with other class ic antiarrhythmics. synthesis note: the carbamate structure reminds the reader of gastrophenzine or particularly ethacizine. synthesis: patents: the amide formation between phenothiazine-2-ethylcarbamate (1) and 3-chloropropionyl chloride (2) gives ethyl n-carbamate (3). displacement of the remaining ω-halogen by morpholine (4) then completes the synthesis of moricizine (5).