▁that ▁gave ▁quick ▁relief ▁for ▁bron ch osp asm ▁and ▁ast h ma . ▁Ep ine phr ine ▁( ad ren alin ) ▁was ▁the ▁first ▁of ▁these , ▁and ▁next ▁came ▁is op ren al ine ▁( is opro ter en ol ). ▁I so eth ar ine ▁was ▁the ▁third ▁drug ▁in ▁this ▁line , ▁thus ▁the ▁third ▁generation ▁or ▁grand d augh ter ▁of ▁the ▁original . ▁ ▁In ▁the ▁western ▁US ▁it ▁was ▁the ▁drug ▁of ▁choice ▁in ▁the ▁late ▁ 1 9 7 0 s ▁and ▁early ▁ 1 9 8 0 s ▁for ▁ne bul ization ▁(" bre ath ing ▁treatment ") ▁to ▁rel ieve ▁air way ▁sp asm . ▁It ▁generally ▁gave ▁sharp ▁relief ▁of ▁short ness ▁of ▁breath , ▁starting ▁within ▁two ▁to ▁five ▁minutes ▁after ▁the ▁patient ▁began ▁breath ing ▁the ▁ne bul ized ▁mist . ▁This ▁rapid ▁on set ▁is ▁not ▁as ▁clearly ▁present ▁in ▁later ▁dru gs . ▁ ▁All ▁of ▁the ▁early ▁ β 2 ▁ag on ist ▁c ate ch ol am ines ▁used ▁for ▁bron ch osp asm ▁had ▁strong ▁side ▁effects , ▁with ▁increase ▁in ▁heart ▁rate ▁as ▁the ▁most ▁common ▁and ▁most ▁problem atic . ▁This ▁came ▁because ▁its ▁" β 2 ▁effect " ▁was ▁not ▁quite ▁as ▁select ive ▁as ▁might ▁be ▁hoped . ▁ β 1 ▁re cept ors ▁appeared ▁to ▁also ▁be ▁stim ulated ▁in ▁some ▁patients , ▁causing ▁card iac ▁and ▁other ▁C NS ▁side ▁effects . ▁With ▁is o et ar ine