., ▁code ine ) ▁as ▁a ▁combined ▁prepar ation . ▁ ▁Ad verse ▁effects ▁Ad verse ▁re actions ▁include ▁de pression ▁of ▁the ▁resp iration , ▁sed ation , ▁coord ination ▁dis orders , ▁const ip ation , ▁and ▁ur inary ▁ret ention . ▁ ▁Long - term ▁administration ▁of ▁the ▁combination ▁product ▁of ▁ter pin ▁hyd rate ▁with ▁code ine ▁may ▁lead ▁to ▁code ine ▁dependence . ▁Ter pin ▁hyd rate ▁with ▁code ine ▁is ▁often ▁mixed ▁with ▁alco hol ▁as ▁code ine ▁is ▁not ▁as ▁readily ▁as ▁sol ub le ▁in ▁water . ▁The ▁high ▁alco hol ▁content ▁( 4 2 ▁percent ) ▁may ▁increase ▁de pression ▁of ▁the ▁central ▁nerv ous ▁system , ▁code ine ▁met abol ism , ▁as ▁well ▁as ▁ab use ▁potential . ▁ ▁Mechan ism ▁of ▁action ▁A ▁hum ect ant ▁and ▁expect or ant , ▁ter pin ▁hyd rate ▁works ▁directly ▁on ▁the ▁bron ch ial ▁secret ory ▁cells ▁in ▁the ▁lower ▁resp ir atory ▁tract ▁to ▁liqu ify ▁and ▁facil itate ▁the ▁elim ination ▁of ▁bron ch ial ▁secret ions . ▁It ▁also ▁ex ert s ▁a ▁weak ▁ant ise ptic ▁effect ▁on ▁the ▁pul mon ary ▁par en chy ma . ▁ ▁History ▁Ter pin ▁hyd rate ▁was ▁first ▁phys i olog ically ▁investig ated ▁by ▁L ép ine ▁in ▁ 1 8 5 5 . ▁He ▁reported ▁that ▁it ▁acted ▁upon ▁the ▁m uc ous ▁memb ran es ▁and ▁also ▁the ▁nerv ous ▁system ▁in ▁a ▁manner ▁similar ▁to ▁the ▁oil ▁of