pranlukast pranlukast pranlukast (brand name onon, オノン) is a cysteinyl leukotriene receptor-1 antagonist. this drug works similarly to merck & co.'s montelukast (singulair). it is widely used in japan. pranlukastclinical datatrade namesonon (オノン)ahfs/drugs.cominternational drug namesroutes ofadministrationoralatc coder03dc02 (who) pharmacokinetic datametabolismhepatic (mainly cyp3a4)elimination half-life1.5 hoursidentifiers iupac name n--4-(4-phenylbutoxy)benzamide cas number103177-37-3 ypubchem cid4887iuphar/bps3634drugbankdb01411 ychemspider4718 yuniitb8z891092chemblchembl21333 ycomptox dashboard (epa)dtxsid3043782 echa infocard100.236.084 chemical and physical dataformulac27h23n5o4molar mass481.512 g·mol−13d model (jsmol)interactive image smiles o=c(nc2cccc3c(=o)cc(c1nnn1)oc23)c5ccc(occccc4ccccc4)cc5 inchi inchi=1s/c27h23n5o4/c33-23-17-24(26-29-31-32-30-26)36-25-21(23)10-6-11-22(25)28-27(34)19-12-14-20(15-13-19)35-16-5-4-9-18-7-2-1-3-8-18/h1-3,6-8,10-15,17h,4-5,9,16h2,(h,28,34)(h,29,30,31,32) ykey:nbqkinxmplxuet-uhfffaoysa-n y (verify) medications of this class, which go under a variety of names according to whether one looks at the american, british or european system of nomenclature, have as their primary function the antagonism of bronchospasm caused, principally in asthmatics, by an allergic reaction to accidentally or inadvertently encountered allergens. medications of this group are normally used as an adjunct to the standard therapy of inhaled steroids with inhaled long- and/or short-acting beta-agonists. there are several similar medications in the group; all appear to be equally effective. pranlukast is also reported as potential inhibitor of mycobacterium tuberculosis infection in experimental models.