▁mouth . ▁ ▁Un common ▁( 1 % ▁to ▁ 1 0 %) ▁— ▁Head ache , ▁psych om ot or ▁imp air ment , ▁der mat itis , ▁and ▁ant im us car in ic ▁effects ▁such ▁as ▁dip lop ia ▁( double ▁vision ), ▁t ach y card ia , ▁const ip ation , ▁ur inary ▁ret ention ▁and ▁g astro - int est inal ▁dist urban ces . ▁ ▁R are ▁( less ▁than ▁ 1 %) ▁— ▁Hyp ers ens itivity ▁re actions ▁( br on ch osp asm , ▁ang io ed ema , ▁an ap hy la xis , ▁r ash es ▁and ▁photos ens itivity ▁re actions ), ▁extra py ram idal ▁effects , ▁d izz iness , ▁confusion , ▁de pression , ▁sleep ▁dist urban ces , ▁trem or , ▁li ver ▁d ys function , ▁and ▁hall uc in ations . ▁ ▁Ph arm ac ology ▁Cy cl iz ine ▁is ▁a ▁pi per azine ▁derivative ▁with ▁hist am ine ▁H 1 - re ceptor ▁ant agon ist ▁( anti h ist am ine ) ▁activity . ▁The ▁precise ▁mechanism ▁of ▁action ▁in ▁in hib iting ▁the ▁sympt oms ▁of ▁motion ▁sick ness ▁is ▁not ▁well ▁understood . ▁It ▁may ▁have ▁effects ▁directly ▁on ▁the ▁vest ib ular ▁system ▁and ▁on ▁the ▁chem ore ceptor ▁trigger ▁zone . ▁Cy cl iz ine ▁ex ert s ▁a ▁central ▁ant ich ol iner g ic ▁( ant im us car in ic ) ▁action . ▁